<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019fa4e7-d33a-7e41-8779-4d8b2e30a78f,g:16a94d9d-45cd-4f24-b292-7e4375ba4fd0-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="acf-20260930.xsd#CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/CONDENSEDCONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_019fa4e7-d515-7ee9-8082-567100a1c4d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_019fa4e7-d515-7f6a-a929-a555ad6e4eb0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_019fa4e7-d515-7ee9-8082-567100a1c4d7" xlink:to="loc_us-gaap_StatementTable_019fa4e7-d515-7f6a-a929-a555ad6e4eb0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d515-7d89-8284-5798fcc1d0ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_019fa4e7-d515-7f6a-a929-a555ad6e4eb0" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d515-7d89-8284-5798fcc1d0ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7d89-8284-5798fcc1d0ae_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d515-7d89-8284-5798fcc1d0ae" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7d89-8284-5798fcc1d0ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7a4c-a32f-e054d33972d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d515-7d89-8284-5798fcc1d0ae" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7a4c-a32f-e054d33972d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_019fa4e7-d515-7d8d-9865-0634e5e40fe1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7a4c-a32f-e054d33972d3" xlink:to="loc_us-gaap_CommonStockMember_019fa4e7-d515-7d8d-9865-0634e5e40fe1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockMember_019fa4e7-d515-7ce6-b645-eeacdfd57e0b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7a4c-a32f-e054d33972d3" xlink:to="loc_us-gaap_PreferredStockMember_019fa4e7-d515-7ce6-b645-eeacdfd57e0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_019fa4e7-d515-7150-98e1-269bf676e803" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7a4c-a32f-e054d33972d3" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_019fa4e7-d515-7150-98e1-269bf676e803" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fa4e7-d515-7643-b793-168566777006" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7a4c-a32f-e054d33972d3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fa4e7-d515-7643-b793-168566777006" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_019fa4e7-d515-7b62-b39d-70e504b93467" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d515-7a4c-a32f-e054d33972d3" xlink:to="loc_us-gaap_RetainedEarningsMember_019fa4e7-d515-7b62-b39d-70e504b93467" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_019fa4e7-d515-7ee9-8082-567100a1c4d7" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019fa4e7-d515-7d42-baba-1d87c932d166" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:to="loc_us-gaap_StockholdersEquity_019fa4e7-d515-7d42-baba-1d87c932d166" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fa4e7-d515-7186-9c4e-10a0c1db681a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:to="loc_us-gaap_NetIncomeLoss_019fa4e7-d515-7186-9c4e-10a0c1db681a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019fa4e7-d515-7b63-b5da-495295f582df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent_019fa4e7-d515-7b63-b5da-495295f582df" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019fa4e7-d515-73c9-80d0-6f1d17e3063f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_019fa4e7-d515-73c9-80d0-6f1d17e3063f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Dividends_019fa4e7-d515-75bb-a554-665d65017225" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Dividends"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:to="loc_us-gaap_Dividends_019fa4e7-d515-75bb-a554-665d65017225" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsPreferredStock_019fa4e7-d515-7963-8ac5-349d28d21fbc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsPreferredStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_019fa4e7-d515-710a-85c4-e23ef96f24ab" xlink:to="loc_us-gaap_DividendsPreferredStock_019fa4e7-d515-7963-8ac5-349d28d21fbc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019fa4e7-d515-7d75-a5a5-878365eb157c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/VariableInterestEntitiesTables" xlink:type="simple" xlink:href="acf-20260930.xsd#VariableInterestEntitiesTables"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/VariableInterestEntitiesTables" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7b2d-b463-7b468a59ae3d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019fa4e7-d516-7ff9-a70a-ca9e897f6a1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7b2d-b463-7b468a59ae3d" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019fa4e7-d516-7ff9-a70a-ca9e897f6a1b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7e1c-abeb-1cb572b7e9cb" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019fa4e7-d516-7ff9-a70a-ca9e897f6a1b" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7e1c-abeb-1cb572b7e9cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7e1c-abeb-1cb572b7e9cb_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7e1c-abeb-1cb572b7e9cb" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7e1c-abeb-1cb572b7e9cb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7b72-bfbb-67e85f011027" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7e1c-abeb-1cb572b7e9cb" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7b72-bfbb-67e85f011027" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_VariableInterestEntityPrimaryBeneficiarySecuritizationandCreditFacilityVIEMember_019fa4e7-d516-736e-9b8a-638f6e668ed5" xlink:href="acf-20260930.xsd#acf_VariableInterestEntityPrimaryBeneficiarySecuritizationandCreditFacilityVIEMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7b72-bfbb-67e85f011027" xlink:to="loc_acf_VariableInterestEntityPrimaryBeneficiarySecuritizationandCreditFacilityVIEMember_019fa4e7-d516-736e-9b8a-638f6e668ed5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTextBlock_019fa4e7-d516-724f-a72f-3271e0d57482" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7b2d-b463-7b468a59ae3d" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTextBlock_019fa4e7-d516-724f-a72f-3271e0d57482" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/MarketableandOtherSecuritiesDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#MarketableandOtherSecuritiesDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/MarketableandOtherSecuritiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:href="acf-20260930.xsd#acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019fa4e7-d516-7d53-a612-f182e949d127" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019fa4e7-d516-7d53-a612-f182e949d127" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7882-a00c-d5eb95541fc7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7882-a00c-d5eb95541fc7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c5c-b46c-aec01998bbc3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c5c-b46c-aec01998bbc3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019fa4e7-d516-75ce-b56f-e5afd9d0b51f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019fa4e7-d516-75ce-b56f-e5afd9d0b51f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7836-92ad-ea509f8055b3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7836-92ad-ea509f8055b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_019fa4e7-d516-7307-a11e-1b72d6070736" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_019fa4e7-d516-7307-a11e-1b72d6070736" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignGovernmentDebtSecuritiesMember_019fa4e7-d516-73e7-bca7-b750c89cb1cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignGovernmentDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:to="loc_us-gaap_ForeignGovernmentDebtSecuritiesMember_019fa4e7-d516-73e7-bca7-b750c89cb1cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_CorporateDebtAndOtherSecuritiesMember_019fa4e7-d516-7afc-95b5-f230ba722a4b" xlink:href="acf-20260930.xsd#acf_CorporateDebtAndOtherSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:to="loc_acf_CorporateDebtAndOtherSecuritiesMember_019fa4e7-d516-7afc-95b5-f230ba722a4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_CashAndTimeDeposits_019fa4e7-d516-7ce1-ab8d-f091595c85b9" xlink:href="acf-20260930.xsd#acf_CashAndTimeDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_acf_CashAndTimeDeposits_019fa4e7-d516-7ce1-ab8d-f091595c85b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019fa4e7-d516-7af0-ad20-ae99c8e0a284" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019fa4e7-d516-7af0-ad20-ae99c8e0a284" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsAtCarryingValue_019fa4e7-d516-78d2-8aaa-b75ef6fc4cc6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_MoneyMarketFundsAtCarryingValue_019fa4e7-d516-78d2-8aaa-b75ef6fc4cc6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019fa4e7-d516-7034-a083-191e5d33178d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019fa4e7-d516-7034-a083-191e5d33178d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_019fa4e7-d516-7be4-88af-4a136d139b2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_019fa4e7-d516-7be4-88af-4a136d139b2d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_RestrictedCashAndMoneyMarketFunds_019fa4e7-d516-79d7-8c38-b1248c1f075a" xlink:href="acf-20260930.xsd#acf_RestrictedCashAndMoneyMarketFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_acf_RestrictedCashAndMoneyMarketFunds_019fa4e7-d516-79d7-8c38-b1248c1f075a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019fa4e7-d516-780b-b5f9-d0f26ca5d841" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019fa4e7-d516-780b-b5f9-d0f26ca5d841" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019fa4e7-d516-7961-a222-41aa9cb36eb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019fa4e7-d516-7961-a222-41aa9cb36eb1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019fa4e7-d516-7fb7-be58-6512d3759178" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/MarketableandOtherSecuritiesDetails_1" xlink:type="simple" xlink:href="acf-20260930.xsd#MarketableandOtherSecuritiesDetails_1"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/MarketableandOtherSecuritiesDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SummaryOfInvestmentHoldingsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:href="acf-20260930.xsd#acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7882-a00c-d5eb95541fc7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7882-a00c-d5eb95541fc7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7882-a00c-d5eb95541fc7" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c5c-b46c-aec01998bbc3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c5c-b46c-aec01998bbc3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_019fa4e7-d516-75ce-b56f-e5afd9d0b51f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77eb-9350-f40fe10148d7" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_019fa4e7-d516-75ce-b56f-e5afd9d0b51f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_ScheduleOfCashCashEquivalentsAndMarketableSecuritiesTable_019fa4e7-d516-7e35-bb23-4c31a9fdfdc8" xlink:to="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7836-92ad-ea509f8055b3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7836-92ad-ea509f8055b3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentAxis_019fa4e7-d516-7836-92ad-ea509f8055b3" xlink:to="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_USTreasuryAndGovernmentMember_019fa4e7-d516-7307-a11e-1b72d6070736" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_USTreasuryAndGovernmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:to="loc_us-gaap_USTreasuryAndGovernmentMember_019fa4e7-d516-7307-a11e-1b72d6070736" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignGovernmentDebtSecuritiesMember_019fa4e7-d516-73e7-bca7-b750c89cb1cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignGovernmentDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:to="loc_us-gaap_ForeignGovernmentDebtSecuritiesMember_019fa4e7-d516-73e7-bca7-b750c89cb1cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_CorporateDebtAndOtherSecuritiesMember_019fa4e7-d516-7afc-95b5-f230ba722a4b" xlink:href="acf-20260930.xsd#acf_CorporateDebtAndOtherSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TransfersAndServicingOfFinancialInstrumentsTypesOfFinancialInstrumentsDomain_019fa4e7-d516-7e31-9d77-8a8e30a8a3da" xlink:to="loc_acf_CorporateDebtAndOtherSecuritiesMember_019fa4e7-d516-7afc-95b5-f230ba722a4b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_CashAndTimeDeposits_019fa4e7-d516-7ce1-ab8d-f091595c85b9" xlink:href="acf-20260930.xsd#acf_CashAndTimeDeposits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_acf_CashAndTimeDeposits_019fa4e7-d516-7ce1-ab8d-f091595c85b9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019fa4e7-d516-7af0-ad20-ae99c8e0a284" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019fa4e7-d516-7af0-ad20-ae99c8e0a284" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MoneyMarketFundsAtCarryingValue_019fa4e7-d516-78d2-8aaa-b75ef6fc4cc6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MoneyMarketFundsAtCarryingValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_MoneyMarketFundsAtCarryingValue_019fa4e7-d516-78d2-8aaa-b75ef6fc4cc6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019fa4e7-d516-7034-a083-191e5d33178d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_CashAndCashEquivalentsFairValueDisclosure_019fa4e7-d516-7034-a083-191e5d33178d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_019fa4e7-d516-7be4-88af-4a136d139b2d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_019fa4e7-d516-7be4-88af-4a136d139b2d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_RestrictedCashAndMoneyMarketFunds_019fa4e7-d516-79d7-8c38-b1248c1f075a" xlink:href="acf-20260930.xsd#acf_RestrictedCashAndMoneyMarketFunds"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_acf_RestrictedCashAndMoneyMarketFunds_019fa4e7-d516-79d7-8c38-b1248c1f075a" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019fa4e7-d516-780b-b5f9-d0f26ca5d841" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesWithinOneYearFairValue_019fa4e7-d516-780b-b5f9-d0f26ca5d841" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019fa4e7-d516-7961-a222-41aa9cb36eb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SummaryOfInvestmentHoldingsLineItems_019fa4e7-d516-7998-a3b7-917633460cb2" xlink:to="loc_us-gaap_AvailableForSaleSecuritiesDebtMaturitiesAfterOneThroughFiveYearsFairValue_019fa4e7-d516-7961-a222-41aa9cb36eb1" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AvailableForSaleSecuritiesDebtSecurities_019fa4e7-d516-7fb7-be58-6512d3759178" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AvailableForSaleSecuritiesDebtSecurities"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#RelatedPartyTransactionsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/RelatedPartyTransactionsNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7482-ba6f-df45b686f43f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7482-ba6f-df45b686f43f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-766d-bb84-f104a7bf07e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7482-ba6f-df45b686f43f" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-766d-bb84-f104a7bf07e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-766d-bb84-f104a7bf07e5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-766d-bb84-f104a7bf07e5" xlink:to="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-766d-bb84-f104a7bf07e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-725f-ad9c-5701b83e4903" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-766d-bb84-f104a7bf07e5" xlink:to="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-725f-ad9c-5701b83e4903" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ParentCompanyMember_019fa4e7-d516-7294-825a-ed7e6905d007" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ParentCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-725f-ad9c-5701b83e4903" xlink:to="loc_srt_ParentCompanyMember_019fa4e7-d516-7294-825a-ed7e6905d007" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-732d-8ab9-ef7b5e485b80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7482-ba6f-df45b686f43f" xlink:to="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-732d-8ab9-ef7b5e485b80" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-732d-8ab9-ef7b5e485b80_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-732d-8ab9-ef7b5e485b80" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-732d-8ab9-ef7b5e485b80_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7560-abf5-4c1b7b39bef8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-732d-8ab9-ef7b5e485b80" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7560-abf5-4c1b7b39bef8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_JuniorSubordinatedRevolvingCreditFacilityMember_019fa4e7-d516-75a1-9e80-3ae81d7a08c9" xlink:href="acf-20260930.xsd#acf_JuniorSubordinatedRevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7560-abf5-4c1b7b39bef8" xlink:to="loc_acf_JuniorSubordinatedRevolvingCreditFacilityMember_019fa4e7-d516-75a1-9e80-3ae81d7a08c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019fa4e7-d516-77f1-830e-9061ca55e172" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7560-abf5-4c1b7b39bef8" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019fa4e7-d516-77f1-830e-9061ca55e172" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019fa4e7-d516-703a-9bf1-3d5b77181811" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7482-ba6f-df45b686f43f" xlink:to="loc_dei_LegalEntityAxis_019fa4e7-d516-703a-9bf1-3d5b77181811" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019fa4e7-d516-703a-9bf1-3d5b77181811_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019fa4e7-d516-703a-9bf1-3d5b77181811" xlink:to="loc_dei_EntityDomain_019fa4e7-d516-703a-9bf1-3d5b77181811_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019fa4e7-d516-7d03-872e-7ade87bf8815" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019fa4e7-d516-703a-9bf1-3d5b77181811" xlink:to="loc_dei_EntityDomain_019fa4e7-d516-7d03-872e-7ade87bf8815" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_GeneralMotorsMember_019fa4e7-d516-74a2-b774-c4e40d9b5d09" xlink:href="acf-20260930.xsd#acf_GeneralMotorsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019fa4e7-d516-7d03-872e-7ade87bf8815" xlink:to="loc_acf_GeneralMotorsMember_019fa4e7-d516-74a2-b774-c4e40d9b5d09" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-766a-8dad-34ae57108a49" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7482-ba6f-df45b686f43f" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-766a-8dad-34ae57108a49" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-766a-8dad-34ae57108a49_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-766a-8dad-34ae57108a49" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-766a-8dad-34ae57108a49_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-71d0-bb3b-90dfd5eecaa5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-766a-8dad-34ae57108a49" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-71d0-bb3b-90dfd5eecaa5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_019fa4e7-d516-7604-bea6-7a264782d97d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-71d0-bb3b-90dfd5eecaa5" xlink:to="loc_us-gaap_LineOfCreditMember_019fa4e7-d516-7604-bea6-7a264782d97d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-7974-9810-743fdaef1503" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7482-ba6f-df45b686f43f" xlink:to="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-7974-9810-743fdaef1503" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-7974-9810-743fdaef1503_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-7974-9810-743fdaef1503" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-7974-9810-743fdaef1503_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-76d9-8731-2c3a272cd5d3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-7974-9810-743fdaef1503" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-76d9-8731-2c3a272cd5d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FiveYearRevolvingCreditFacilityMember_019fa4e7-d516-7692-9b2b-4edbd81629cc" xlink:href="acf-20260930.xsd#acf_FiveYearRevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-76d9-8731-2c3a272cd5d3" xlink:to="loc_acf_FiveYearRevolvingCreditFacilityMember_019fa4e7-d516-7692-9b2b-4edbd81629cc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_ThreeYearRevolvingCreditFacilityExpiringMarch2028Member_019fa4e7-d516-7ba6-b9dc-467feb728b5f" xlink:href="acf-20260930.xsd#acf_ThreeYearRevolvingCreditFacilityExpiringMarch2028Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-76d9-8731-2c3a272cd5d3" xlink:to="loc_acf_ThreeYearRevolvingCreditFacilityExpiringMarch2028Member_019fa4e7-d516-7ba6-b9dc-467feb728b5f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_ThreeHundredandSixtyFourDayRevolvingCreditFacilitiesMember_019fa4e7-d516-7de0-acf2-94a949b09dfb" xlink:href="acf-20260930.xsd#acf_ThreeHundredandSixtyFourDayRevolvingCreditFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-76d9-8731-2c3a272cd5d3" xlink:to="loc_acf_ThreeHundredandSixtyFourDayRevolvingCreditFacilitiesMember_019fa4e7-d516-7de0-acf2-94a949b09dfb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019fa4e7-d516-70dc-a3bf-f620d2652174" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:to="loc_us-gaap_Revenues_019fa4e7-d516-70dc-a3bf-f620d2652174" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTaxExpenseDueToAffiliatesDeferred_019fa4e7-d516-7eb5-900d-6f2c69b7351c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTaxExpenseDueToAffiliatesDeferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:to="loc_us-gaap_RelatedPartyTaxExpenseDueToAffiliatesDeferred_019fa4e7-d516-7eb5-900d-6f2c69b7351c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_LineOfCreditFacilitiesRelatedPartyFacility_019fa4e7-d516-755a-8b8f-08c0cf14113c" xlink:href="acf-20260930.xsd#acf_LineOfCreditFacilitiesRelatedPartyFacility"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:to="loc_acf_LineOfCreditFacilitiesRelatedPartyFacility_019fa4e7-d516-755a-8b8f-08c0cf14113c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019fa4e7-d516-7bd6-b898-53d36c582e3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019fa4e7-d516-7bd6-b898-53d36c582e3c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_019fa4e7-d516-74d7-b308-29f3f32a3ebf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:to="loc_us-gaap_DebtInstrumentTerm_019fa4e7-d516-74d7-b308-29f3f32a3ebf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019fa4e7-d516-72cc-8bb9-4548340686ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7008-bcbf-a7d4a126b8f7" xlink:to="loc_us-gaap_LineOfCreditFacilityCurrentBorrowingCapacity_019fa4e7-d516-72cc-8bb9-4548340686ef" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/RelatedPartyTransactionsScheduleofRelatedPartyTransactionsDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#RelatedPartyTransactionsScheduleofRelatedPartyTransactionsDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/RelatedPartyTransactionsScheduleofRelatedPartyTransactionsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7fa4-b6a3-0b2206d602eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:to="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7fa4-b6a3-0b2206d602eb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-73d1-94bb-4fb634415a3f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7fa4-b6a3-0b2206d602eb" xlink:to="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-73d1-94bb-4fb634415a3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-73d1-94bb-4fb634415a3f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-73d1-94bb-4fb634415a3f" xlink:to="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-73d1-94bb-4fb634415a3f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-7a9a-aeba-7b76f2c7584b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_019fa4e7-d516-73d1-94bb-4fb634415a3f" xlink:to="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-7a9a-aeba-7b76f2c7584b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RelatedPartyMember_019fa4e7-d516-777c-9111-72bdad853a36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RelatedPartyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyDomain_019fa4e7-d516-7a9a-aeba-7b76f2c7584b" xlink:to="loc_us-gaap_RelatedPartyMember_019fa4e7-d516-777c-9111-72bdad853a36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7a06-99e3-2f464d255923" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_019fa4e7-d516-7fa4-b6a3-0b2206d602eb" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7a06-99e3-2f464d255923" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7a06-99e3-2f464d255923_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7a06-99e3-2f464d255923" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7a06-99e3-2f464d255923_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7720-a665-c6be9097a023" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7a06-99e3-2f464d255923" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7720-a665-c6be9097a023" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7dc7-9e6f-ff31a7ce6480" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7720-a665-c6be9097a023" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7dc7-9e6f-ff31a7ce6480" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-78e4-a992-794720d7f210" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7720-a665-c6be9097a023" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-78e4-a992-794720d7f210" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-7055-b1b9-394c0600684f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:to="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-7055-b1b9-394c0600684f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_IntercompanySubventionReceivable_019fa4e7-d516-7b97-87d4-b38c9eb57173" xlink:href="acf-20260930.xsd#acf_IntercompanySubventionReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:to="loc_acf_IntercompanySubventionReceivable_019fa4e7-d516-7b97-87d4-b38c9eb57173" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesPayable_019fa4e7-d516-7b6d-946a-aa22c9d45791" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesPayable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:to="loc_us-gaap_NotesPayable_019fa4e7-d516-7b6d-946a-aa22c9d45791" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxesPayableCurrentAndNoncurrent_019fa4e7-d516-7e5a-8461-cd680f2386df" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_TaxesPayableCurrentAndNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:to="loc_us-gaap_TaxesPayableCurrentAndNoncurrent_019fa4e7-d516-7e5a-8461-cd680f2386df" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeOperating_019fa4e7-d516-7f49-b3e9-592b5192ae5f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestIncomeOperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:to="loc_us-gaap_InterestIncomeOperating_019fa4e7-d516-7f49-b3e9-592b5192ae5f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_RelatedPartyLeasedVehicleIncomeEarned_019fa4e7-d516-78c5-bbc4-b4c46c2c3128" xlink:href="acf-20260930.xsd#acf_RelatedPartyLeasedVehicleIncomeEarned"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RelatedPartyTransactionLineItems_019fa4e7-d516-7e3e-a8de-82c70dc2e478" xlink:to="loc_acf_RelatedPartyLeasedVehicleIncomeEarned_019fa4e7-d516-78c5-bbc4-b4c46c2c3128" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofFinanceReceivablesNetDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#FinanceReceivablesScheduleofFinanceReceivablesNetDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofFinanceReceivablesNetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7b8c-b6e7-b401e0bf412f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-78c1-9ae7-b300f18e681e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7b8c-b6e7-b401e0bf412f" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-78c1-9ae7-b300f18e681e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7dea-984f-1afd5bcd0eb4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-78c1-9ae7-b300f18e681e" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7dea-984f-1afd5bcd0eb4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7dea-984f-1afd5bcd0eb4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7dea-984f-1afd5bcd0eb4" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7dea-984f-1afd5bcd0eb4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-79a3-8b00-b9fc5dc636a3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7dea-984f-1afd5bcd0eb4" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-79a3-8b00-b9fc5dc636a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-757f-9084-ae65ac522915" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-79a3-8b00-b9fc5dc636a3" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-757f-9084-ae65ac522915" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7569-9e56-1edb91590868" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-79a3-8b00-b9fc5dc636a3" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7569-9e56-1edb91590868" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-75b1-bd4c-6598b41a75ea" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-78c1-9ae7-b300f18e681e" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-75b1-bd4c-6598b41a75ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-75b1-bd4c-6598b41a75ea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-75b1-bd4c-6598b41a75ea" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-75b1-bd4c-6598b41a75ea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7e55-9379-2db7e2663aa9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-75b1-bd4c-6598b41a75ea" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7e55-9379-2db7e2663aa9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7d9d-9c3f-fe42a60bfb36" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7e55-9379-2db7e2663aa9" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7d9d-9c3f-fe42a60bfb36" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019fa4e7-d516-7fbf-af27-0c9f55214b80" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7e55-9379-2db7e2663aa9" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019fa4e7-d516-7fbf-af27-0c9f55214b80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-75e7-a60d-580fe14037b6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-78c1-9ae7-b300f18e681e" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-75e7-a60d-580fe14037b6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-75e7-a60d-580fe14037b6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-75e7-a60d-580fe14037b6" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-75e7-a60d-580fe14037b6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7f08-975a-488ef148b68c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-75e7-a60d-580fe14037b6" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7f08-975a-488ef148b68c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_DealerFinancingMember_019fa4e7-d516-76ca-ac86-fcda09ce8ee5" xlink:href="acf-20260930.xsd#acf_DealerFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7f08-975a-488ef148b68c" xlink:to="loc_acf_DealerFinancingMember_019fa4e7-d516-76ca-ac86-fcda09ce8ee5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_OtherFinancingMember_019fa4e7-d516-7eec-a900-1d728f92479d" xlink:href="acf-20260930.xsd#acf_OtherFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7f08-975a-488ef148b68c" xlink:to="loc_acf_OtherFinancingMember_019fa4e7-d516-7eec-a900-1d728f92479d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-7aae-9d0c-c95566057a6b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7b8c-b6e7-b401e0bf412f" xlink:to="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-7aae-9d0c-c95566057a6b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019fa4e7-d516-7872-b487-2963c63e0b4f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7b8c-b6e7-b401e0bf412f" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019fa4e7-d516-7872-b487-2963c63e0b4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_019fa4e7-d516-71d5-a001-f5fd234b89a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7b8c-b6e7-b401e0bf412f" xlink:to="loc_us-gaap_NotesReceivableNet_019fa4e7-d516-71d5-a001-f5fd234b89a8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReceivablesFairValueDisclosure_019fa4e7-d516-7949-b985-f3bd4a40814e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReceivablesFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7b8c-b6e7-b401e0bf412f" xlink:to="loc_us-gaap_ReceivablesFairValueDisclosure_019fa4e7-d516-7949-b985-f3bd4a40814e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashEquivalents_019fa4e7-d516-7d7e-9181-6d6ea537f59b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7b8c-b6e7-b401e0bf412f" xlink:to="loc_us-gaap_RestrictedCashEquivalents_019fa4e7-d516-7d7e-9181-6d6ea537f59b" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofAllowanceforCreditLossesonFinancingReceivablesDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#FinanceReceivablesScheduleofAllowanceforCreditLossesonFinancingReceivablesDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofAllowanceforCreditLossesonFinancingReceivablesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_019fa4e7-d516-78f8-aee9-213bbc890049" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_019fa4e7-d516-74ff-b1b4-ac5047f5baf2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_019fa4e7-d516-78f8-aee9-213bbc890049" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_019fa4e7-d516-74ff-b1b4-ac5047f5baf2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-754f-90e9-307366a74c24" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableAllowanceForCreditLossesTable_019fa4e7-d516-74ff-b1b4-ac5047f5baf2" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-754f-90e9-307366a74c24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-754f-90e9-307366a74c24_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-754f-90e9-307366a74c24" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-754f-90e9-307366a74c24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-761f-9c1c-3093f911f84d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-754f-90e9-307366a74c24" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-761f-9c1c-3093f911f84d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-72bb-8e08-06bd1e8b0f74" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-761f-9c1c-3093f911f84d" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-72bb-8e08-06bd1e8b0f74" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019fa4e7-d516-705c-b2ab-d2cf29515d44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems_019fa4e7-d516-78f8-aee9-213bbc890049" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019fa4e7-d516-705c-b2ab-d2cf29515d44" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019fa4e7-d516-7e1f-a2a5-0d25ca97db5d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019fa4e7-d516-705c-b2ab-d2cf29515d44" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019fa4e7-d516-7e1f-a2a5-0d25ca97db5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_019fa4e7-d516-7942-8ac3-86b8307e774b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLeaseAndOtherLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019fa4e7-d516-705c-b2ab-d2cf29515d44" xlink:to="loc_us-gaap_ProvisionForLoanLeaseAndOtherLosses_019fa4e7-d516-7942-8ac3-86b8307e774b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019fa4e7-d516-792e-8282-f5aba864efbf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019fa4e7-d516-705c-b2ab-d2cf29515d44" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019fa4e7-d516-792e-8282-f5aba864efbf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_019fa4e7-d516-785c-a2bc-105ac05eadb1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019fa4e7-d516-705c-b2ab-d2cf29515d44" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRecovery_019fa4e7-d516-785c-a2bc-105ac05eadb1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossForeignCurrencyTranslation_019fa4e7-d516-715d-b0a3-3018962e53c8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossForeignCurrencyTranslation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesRollForward_019fa4e7-d516-705c-b2ab-d2cf29515d44" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossForeignCurrencyTranslation_019fa4e7-d516-715d-b0a3-3018962e53c8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLosses_019fa4e7-d516-7ab8-9df2-5513e4306a27" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLosses"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/FinanceReceivablesNarrativeDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#FinanceReceivablesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/FinanceReceivablesNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-72b4-840d-e6bfffbc66f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-75db-99e2-bf5ef4226ca6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-72b4-840d-e6bfffbc66f5" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-75db-99e2-bf5ef4226ca6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7427-9718-30f77b8740f5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-75db-99e2-bf5ef4226ca6" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7427-9718-30f77b8740f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7427-9718-30f77b8740f5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7427-9718-30f77b8740f5" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7427-9718-30f77b8740f5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-73da-b1b6-0427e59fbd95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7427-9718-30f77b8740f5" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-73da-b1b6-0427e59fbd95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-789e-8ea2-35b6d8e64941" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-73da-b1b6-0427e59fbd95" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-789e-8ea2-35b6d8e64941" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7445-b5ef-9a3c74c0fcf8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-73da-b1b6-0427e59fbd95" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7445-b5ef-9a3c74c0fcf8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-7141-b70e-56178592deab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-75db-99e2-bf5ef4226ca6" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-7141-b70e-56178592deab" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7141-b70e-56178592deab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-7141-b70e-56178592deab" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7141-b70e-56178592deab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7e59-9e16-6aaa1cd95492" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-7141-b70e-56178592deab" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7e59-9e16-6aaa1cd95492" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FloorplanAdvancesMember_019fa4e7-d516-77fb-b296-086fb2009430" xlink:href="acf-20260930.xsd#acf_FloorplanAdvancesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7e59-9e16-6aaa1cd95492" xlink:to="loc_acf_FloorplanAdvancesMember_019fa4e7-d516-77fb-b296-086fb2009430" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_FinancingReceivableAllowanceForCreditLossToNonaccrualPercent_019fa4e7-d516-77ea-98ff-c588dbdbba33" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_FinancingReceivableAllowanceForCreditLossToNonaccrualPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-72b4-840d-e6bfffbc66f5" xlink:to="loc_srt_FinancingReceivableAllowanceForCreditLossToNonaccrualPercent_019fa4e7-d516-77ea-98ff-c588dbdbba33" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_019fa4e7-d516-746a-bc95-63875f145ea8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-72b4-840d-e6bfffbc66f5" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus_019fa4e7-d516-746a-bc95-63875f145ea8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivableRevolvingPercentOfTotal_019fa4e7-d516-74c8-849e-b020d78d4565" xlink:href="acf-20260930.xsd#acf_FinancingReceivableRevolvingPercentOfTotal"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-72b4-840d-e6bfffbc66f5" xlink:to="loc_acf_FinancingReceivableRevolvingPercentOfTotal_019fa4e7-d516-74c8-849e-b020d78d4565" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivableAllowanceForCreditLossModificationOfLoans_019fa4e7-d516-7e1d-9192-dc75a27009c8" xlink:href="acf-20260930.xsd#acf_FinancingReceivableAllowanceForCreditLossModificationOfLoans"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-72b4-840d-e6bfffbc66f5" xlink:to="loc_acf_FinancingReceivableAllowanceForCreditLossModificationOfLoans_019fa4e7-d516-7e1d-9192-dc75a27009c8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding_019fa4e7-d516-77c2-83c9-8422e033d27b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-72b4-840d-e6bfffbc66f5" xlink:to="loc_us-gaap_ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding_019fa4e7-d516-77c2-83c9-8422e033d27b" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofFinancingReceivableCreditQualityIndicatorsDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#FinanceReceivablesScheduleofFinancingReceivableCreditQualityIndicatorsDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofFinancingReceivableCreditQualityIndicatorsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_019fa4e7-d516-76d4-8874-60ca8049e611" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_019fa4e7-d516-76d4-8874-60ca8049e611" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditScoreFicoAxis_019fa4e7-d516-7429-8af4-cd7ca6cff4d5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditScoreFicoAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_019fa4e7-d516-76d4-8874-60ca8049e611" xlink:to="loc_us-gaap_CreditScoreFicoAxis_019fa4e7-d516-7429-8af4-cd7ca6cff4d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditScoreFicoDomain_019fa4e7-d516-7429-8af4-cd7ca6cff4d5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditScoreFicoDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditScoreFicoAxis_019fa4e7-d516-7429-8af4-cd7ca6cff4d5" xlink:to="loc_us-gaap_CreditScoreFicoDomain_019fa4e7-d516-7429-8af4-cd7ca6cff4d5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditScoreFicoDomain_019fa4e7-d516-77b8-bef7-07dd7feb65fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditScoreFicoDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditScoreFicoAxis_019fa4e7-d516-7429-8af4-cd7ca6cff4d5" xlink:to="loc_us-gaap_CreditScoreFicoDomain_019fa4e7-d516-77b8-bef7-07dd7feb65fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FICOScoreGreaterThan680Member_019fa4e7-d516-7860-8713-88d50d7b1ca4" xlink:href="acf-20260930.xsd#acf_FICOScoreGreaterThan680Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditScoreFicoDomain_019fa4e7-d516-77b8-bef7-07dd7feb65fd" xlink:to="loc_acf_FICOScoreGreaterThan680Member_019fa4e7-d516-7860-8713-88d50d7b1ca4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FICOScore620To679Member_019fa4e7-d516-729c-a0ea-ca5dab1b247a" xlink:href="acf-20260930.xsd#acf_FICOScore620To679Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditScoreFicoDomain_019fa4e7-d516-77b8-bef7-07dd7feb65fd" xlink:to="loc_acf_FICOScore620To679Member_019fa4e7-d516-729c-a0ea-ca5dab1b247a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FICOScoreLessThan620Member_019fa4e7-d516-772b-b57c-417f455a9abe" xlink:href="acf-20260930.xsd#acf_FICOScoreLessThan620Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditScoreFicoDomain_019fa4e7-d516-77b8-bef7-07dd7feb65fd" xlink:to="loc_acf_FICOScoreLessThan620Member_019fa4e7-d516-772b-b57c-417f455a9abe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7de6-87e0-ee4978b765ec" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivableRecordedInvestmentCreditQualityIndicatorTable_019fa4e7-d516-76d4-8874-60ca8049e611" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7de6-87e0-ee4978b765ec" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7de6-87e0-ee4978b765ec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7de6-87e0-ee4978b765ec" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7de6-87e0-ee4978b765ec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7b08-a16e-0b24ccfb6e62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7de6-87e0-ee4978b765ec" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7b08-a16e-0b24ccfb6e62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-7cd6-bce2-b20102595d0e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7b08-a16e-0b24ccfb6e62" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-7cd6-bce2-b20102595d0e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019fa4e7-d516-79f9-8ab1-1fdf079aa957" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019fa4e7-d516-79f9-8ab1-1fdf079aa957" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019fa4e7-d516-7e93-8029-8bb2a5b7ba3b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019fa4e7-d516-7e93-8029-8bb2a5b7ba3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019fa4e7-d516-73e8-892c-fb38eef24108" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019fa4e7-d516-73e8-892c-fb38eef24108" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear_019fa4e7-d516-7a6e-966c-4c6e198e1195" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear_019fa4e7-d516-7a6e-966c-4c6e198e1195" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear_019fa4e7-d516-7a6b-88b2-8287f6e37db6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear_019fa4e7-d516-7a6b-88b2-8287f6e37db6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear_019fa4e7-d516-7fc0-aa39-2f93d184ad52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear_019fa4e7-d516-7fc0-aa39-2f93d184ad52" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-79c5-becb-105acc390ad5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-79c5-becb-105acc390ad5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivableBeforeAllowanceForCreditLossPercent_019fa4e7-d516-7bb1-b024-7ccd30abce5b" xlink:href="acf-20260930.xsd#acf_FinancingReceivableBeforeAllowanceForCreditLossPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentLineItems_019fa4e7-d516-7532-8e96-db0898191522" xlink:to="loc_acf_FinancingReceivableBeforeAllowanceForCreditLossPercent_019fa4e7-d516-7bb1-b024-7ccd30abce5b" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofDelinquencyDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#FinanceReceivablesScheduleofDelinquencyDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofDelinquencyDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019fa4e7-d516-7375-99d6-2d087b480753" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfFinancingReceivablesPastDueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019fa4e7-d516-7375-99d6-2d087b480753" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7cbe-94a3-b396f0125829" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019fa4e7-d516-7375-99d6-2d087b480753" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7cbe-94a3-b396f0125829" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7cbe-94a3-b396f0125829_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7cbe-94a3-b396f0125829" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7cbe-94a3-b396f0125829_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7ff0-9c87-9d726eb71be5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7cbe-94a3-b396f0125829" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7ff0-9c87-9d726eb71be5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-7392-af67-c5059915e3e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ConsumerPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7ff0-9c87-9d726eb71be5" xlink:to="loc_us-gaap_ConsumerPortfolioSegmentMember_019fa4e7-d516-7392-af67-c5059915e3e5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_019fa4e7-d516-71e1-a1c3-583b1c3247a4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019fa4e7-d516-7375-99d6-2d087b480753" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_019fa4e7-d516-71e1-a1c3-583b1c3247a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_019fa4e7-d516-71e1-a1c3-583b1c3247a4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_019fa4e7-d516-71e1-a1c3-583b1c3247a4" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_019fa4e7-d516-71e1-a1c3-583b1c3247a4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_019fa4e7-d516-7d66-9557-2b0046fcb9be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialInstrumentPerformanceStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusAxis_019fa4e7-d516-71e1-a1c3-583b1c3247a4" xlink:to="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_019fa4e7-d516-7d66-9557-2b0046fcb9be" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformingFinancingReceivableMember_019fa4e7-d516-7ff9-85b7-00fa1337f30b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PerformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_019fa4e7-d516-7d66-9557-2b0046fcb9be" xlink:to="loc_us-gaap_PerformingFinancingReceivableMember_019fa4e7-d516-7ff9-85b7-00fa1337f30b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonperformingFinancingReceivableMember_019fa4e7-d516-790b-8b22-84d7d315e705" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NonperformingFinancingReceivableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancialInstrumentPerformanceStatusDomain_019fa4e7-d516-7d66-9557-2b0046fcb9be" xlink:to="loc_us-gaap_NonperformingFinancingReceivableMember_019fa4e7-d516-790b-8b22-84d7d315e705" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019fa4e7-d516-76b4-9467-69bee03df51e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFinancingReceivablesPastDueTable_019fa4e7-d516-7375-99d6-2d087b480753" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019fa4e7-d516-76b4-9467-69bee03df51e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-76b4-9467-69bee03df51e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019fa4e7-d516-76b4-9467-69bee03df51e" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-76b4-9467-69bee03df51e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablesPeriodPastDueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueAxis_019fa4e7-d516-76b4-9467-69bee03df51e" xlink:to="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancialAssetNotPastDueMember_019fa4e7-d516-7bd1-90e1-d845c6d8e13c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancialAssetNotPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:to="loc_us-gaap_FinancialAssetNotPastDueMember_019fa4e7-d516-7bd1-90e1-d845c6d8e13c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivables31to60DaysPastDueMember_019fa4e7-d516-7f5d-a046-d1c1db7b7373" xlink:href="acf-20260930.xsd#acf_FinancingReceivables31to60DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:to="loc_acf_FinancingReceivables31to60DaysPastDueMember_019fa4e7-d516-7f5d-a046-d1c1db7b7373" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivablesGreaterThan60DaysPastDueMember_019fa4e7-d516-782a-aa2f-111e2cfdbad0" xlink:href="acf-20260930.xsd#acf_FinancingReceivablesGreaterThan60DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:to="loc_acf_FinancingReceivablesGreaterThan60DaysPastDueMember_019fa4e7-d516-782a-aa2f-111e2cfdbad0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivablesGreaterthan30DaysPastDueMember_019fa4e7-d516-772f-91b5-b23c02d5dd1d" xlink:href="acf-20260930.xsd#acf_FinancingReceivablesGreaterthan30DaysPastDueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:to="loc_acf_FinancingReceivablesGreaterthan30DaysPastDueMember_019fa4e7-d516-772f-91b5-b23c02d5dd1d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivablesInRepossessionMember_019fa4e7-d516-7148-bf3d-10ba9bc87419" xlink:href="acf-20260930.xsd#acf_FinancingReceivablesInRepossessionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:to="loc_acf_FinancingReceivablesInRepossessionMember_019fa4e7-d516-7148-bf3d-10ba9bc87419" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinanceReceivablesMoreThan30DaysDelinquentOrInRepossesionMember_019fa4e7-d516-7234-9fc3-a6ee9a3e9187" xlink:href="acf-20260930.xsd#acf_FinanceReceivablesMoreThan30DaysDelinquentOrInRepossesionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablesPeriodPastDueDomain_019fa4e7-d516-7878-a7e2-b6cc299178c0" xlink:to="loc_acf_FinanceReceivablesMoreThan30DaysDelinquentOrInRepossesionMember_019fa4e7-d516-7234-9fc3-a6ee9a3e9187" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019fa4e7-d516-700f-88f2-f487ff9fcf1c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019fa4e7-d516-700f-88f2-f487ff9fcf1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019fa4e7-d516-7cee-9753-59fd96e2732f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019fa4e7-d516-7cee-9753-59fd96e2732f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019fa4e7-d516-7d64-a19b-899f72d0866c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019fa4e7-d516-7d64-a19b-899f72d0866c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear_019fa4e7-d516-7875-991c-c43d6f8ee87c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear_019fa4e7-d516-7875-991c-c43d6f8ee87c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear_019fa4e7-d516-7a79-abe7-99fb47c6f3af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear_019fa4e7-d516-7a79-abe7-99fb47c6f3af" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear_019fa4e7-d516-7a32-8693-1c61c8d775af" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear_019fa4e7-d516-7a32-8693-1c61c8d775af" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-7841-b1c5-caa044ca560c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-7841-b1c5-caa044ca560c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePercentPastDue1_019fa4e7-d516-7adf-99e8-4b5e2c4ff0ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePercentPastDue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivablePercentPastDue1_019fa4e7-d516-7adf-99e8-4b5e2c4ff0ae" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentPastDueLineItems_019fa4e7-d516-7428-96ba-fa009bd05556" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearOneOriginatedCurrentFiscalYearWriteoff_019fa4e7-d516-7026-b1e0-ae18a2a3d3c6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableYearOneOriginatedCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:to="loc_us-gaap_FinancingReceivableYearOneOriginatedCurrentFiscalYearWriteoff_019fa4e7-d516-7026-b1e0-ae18a2a3d3c6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-702b-930b-e44f56edb532" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:to="loc_us-gaap_FinancingReceivableYearTwoOriginatedFiscalYearBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-702b-930b-e44f56edb532" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-7e48-93d0-8fefd500c961" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:to="loc_us-gaap_FinancingReceivableYearThreeOriginatedTwoYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-7e48-93d0-8fefd500c961" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-717d-840a-55bc9b5c452c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:to="loc_us-gaap_FinancingReceivableYearFourOriginatedThreeYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-717d-840a-55bc9b5c452c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-7080-bd63-2e5a8894f5cb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:to="loc_us-gaap_FinancingReceivableYearFiveOriginatedFourYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-7080-bd63-2e5a8894f5cb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-7ae0-af74-d5b31bbf5a7f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:to="loc_us-gaap_FinancingReceivableOriginatedMoreThanFiveYearsBeforeCurrentFiscalYearWriteoff_019fa4e7-d516-7ae0-af74-d5b31bbf5a7f" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019fa4e7-d516-73f0-8ed9-566f43dc48c5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableAllowanceForCreditLossWriteoffByOriginationYearAbstract_019fa4e7-d516-78c0-b949-9a31c584bec8" xlink:to="loc_us-gaap_FinancingReceivableAllowanceForCreditLossesWriteOffs_019fa4e7-d516-73f0-8ed9-566f43dc48c5" xlink:type="arc" order="7"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofCreditRiskProfilebyDealerDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#FinanceReceivablesScheduleofCreditRiskProfilebyDealerDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/FinanceReceivablesScheduleofCreditRiskProfilebyDealerDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccountsNotesAndLoansReceivableLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-7de6-bb6b-9090fd220c15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-7de6-bb6b-9090fd220c15" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7f4e-972f-ce440e23e956" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-7de6-bb6b-9090fd220c15" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7f4e-972f-ce440e23e956" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7f4e-972f-ce440e23e956_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7f4e-972f-ce440e23e956" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7f4e-972f-ce440e23e956_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7bfd-8799-46607fd7aea6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivablePortfolioSegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentAxis_019fa4e7-d516-7f4e-972f-ce440e23e956" xlink:to="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7bfd-8799-46607fd7aea6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7aa0-8ace-ac73b15a97aa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommercialPortfolioSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivablePortfolioSegmentDomain_019fa4e7-d516-7bfd-8799-46607fd7aea6" xlink:to="loc_us-gaap_CommercialPortfolioSegmentMember_019fa4e7-d516-7aa0-8ace-ac73b15a97aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-745a-ad45-2e7532b622f2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-7de6-bb6b-9090fd220c15" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-745a-ad45-2e7532b622f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-745a-ad45-2e7532b622f2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-745a-ad45-2e7532b622f2" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-745a-ad45-2e7532b622f2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7d03-8f92-2d341e0eb348" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis_019fa4e7-d516-745a-ad45-2e7532b622f2" xlink:to="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7d03-8f92-2d341e0eb348" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_DealerFinancingMember_019fa4e7-d516-70a8-89b0-404de374012b" xlink:href="acf-20260930.xsd#acf_DealerFinancingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FinancingReceivableRecordedInvestmentClassOfFinancingReceivableDomain_019fa4e7-d516-7d03-8f92-2d341e0eb348" xlink:to="loc_acf_DealerFinancingMember_019fa4e7-d516-70a8-89b0-404de374012b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentAxis_019fa4e7-d516-79de-b7f3-b3ad78b4c926" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAccountsNotesLoansAndFinancingReceivableTable_019fa4e7-d516-7de6-bb6b-9090fd220c15" xlink:to="loc_us-gaap_InternalCreditAssessmentAxis_019fa4e7-d516-79de-b7f3-b3ad78b4c926" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-79de-b7f3-b3ad78b4c926_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_019fa4e7-d516-79de-b7f3-b3ad78b4c926" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-79de-b7f3-b3ad78b4c926_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-7c0f-9a5e-b7296162f00b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalCreditAssessmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_InternalCreditAssessmentAxis_019fa4e7-d516-79de-b7f3-b3ad78b4c926" xlink:to="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-7c0f-9a5e-b7296162f00b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InternalInvestmentGradeMember_019fa4e7-d516-7164-a9ee-806da3379024" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InternalInvestmentGradeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-7c0f-9a5e-b7296162f00b" xlink:to="loc_us-gaap_InternalInvestmentGradeMember_019fa4e7-d516-7164-a9ee-806da3379024" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SpecialMentionMember_019fa4e7-d516-7db7-bbcc-9068a23b2374" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SpecialMentionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-7c0f-9a5e-b7296162f00b" xlink:to="loc_us-gaap_SpecialMentionMember_019fa4e7-d516-7db7-bbcc-9068a23b2374" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubstandardMember_019fa4e7-d516-73b3-9f1e-53d6ea7ba511" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubstandardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-7c0f-9a5e-b7296162f00b" xlink:to="loc_us-gaap_SubstandardMember_019fa4e7-d516-73b3-9f1e-53d6ea7ba511" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubprimeMember_019fa4e7-d516-7a7a-955a-444063905c03" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubprimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_InternalCreditAssessmentDomain_019fa4e7-d516-7c0f-9a5e-b7296162f00b" xlink:to="loc_us-gaap_SubprimeMember_019fa4e7-d516-7a7a-955a-444063905c03" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableRevolving_019fa4e7-d516-74a7-b7e0-f273f7f37587" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableRevolving"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_FinancingReceivableRevolving_019fa4e7-d516-74a7-b7e0-f273f7f37587" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019fa4e7-d516-77cd-a4ae-04381db59f69" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInCurrentFiscalYear_019fa4e7-d516-77cd-a4ae-04381db59f69" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019fa4e7-d516-753e-ac84-e39d2acfb133" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_FinancingReceivableOriginatedInFiscalYearBeforeLatestFiscalYear_019fa4e7-d516-753e-ac84-e39d2acfb133" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019fa4e7-d516-75a4-ac4f-db245894a906" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_FinancingReceivableOriginatedTwoYearsBeforeLatestFiscalYear_019fa4e7-d516-75a4-ac4f-db245894a906" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear_019fa4e7-d516-7854-b49a-fe68d017a7a0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_FinancingReceivableOriginatedThreeYearsBeforeLatestFiscalYear_019fa4e7-d516-7854-b49a-fe68d017a7a0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear_019fa4e7-d516-77af-8425-b5be94d30434" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_FinancingReceivableOriginatedFourYearsBeforeLatestFiscalYear_019fa4e7-d516-77af-8425-b5be94d30434" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear_019fa4e7-d516-7ec1-9a00-de06739259e6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_FinancingReceivableOriginatedFiveOrMoreYearsBeforeLatestFiscalYear_019fa4e7-d516-7ec1-9a00-de06739259e6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-70a9-8f35-a208d58b7336" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_us-gaap_NotesReceivableGross_019fa4e7-d516-70a9-8f35-a208d58b7336" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_FinancingReceivableBeforeAllowanceForCreditLossPercent_019fa4e7-d516-7dd6-9dea-828d6eb48f9a" xlink:href="acf-20260930.xsd#acf_FinancingReceivableBeforeAllowanceForCreditLossPercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccountsNotesAndLoansReceivableLineItems_019fa4e7-d516-7499-96e1-18879685da1a" xlink:to="loc_acf_FinancingReceivableBeforeAllowanceForCreditLossPercent_019fa4e7-d516-7dd6-9dea-828d6eb48f9a" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/EquityinNetAssetsofNonconsolidatedAffiliatesDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#EquityinNetAssetsofNonconsolidatedAffiliatesDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/EquityinNetAssetsofNonconsolidatedAffiliatesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterestLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestTable_019fa4e7-d516-7e30-b59b-b9eb7b4881d0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_MinorityInterestTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:to="loc_us-gaap_MinorityInterestTable_019fa4e7-d516-7e30-b59b-b9eb7b4881d0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019fa4e7-d516-7a17-930d-228441b50089" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_019fa4e7-d516-7e30-b59b-b9eb7b4881d0" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019fa4e7-d516-7a17-930d-228441b50089" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019fa4e7-d516-7a17-930d-228441b50089_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019fa4e7-d516-7a17-930d-228441b50089" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019fa4e7-d516-7a17-930d-228441b50089_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_019fa4e7-d516-7db9-bf7d-63978f2d8840" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_019fa4e7-d516-7a17-930d-228441b50089" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_019fa4e7-d516-7db9-bf7d-63978f2d8840" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_AICGMACSAICGMFLeasingCo.andPTSGMWMultifinanceIndonesiaMember_019fa4e7-d516-75a5-b4ef-298b7cad5881" xlink:href="acf-20260930.xsd#acf_AICGMACSAICGMFLeasingCo.andPTSGMWMultifinanceIndonesiaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019fa4e7-d516-7db9-bf7d-63978f2d8840" xlink:to="loc_acf_AICGMACSAICGMFLeasingCo.andPTSGMWMultifinanceIndonesiaMember_019fa4e7-d516-75a5-b4ef-298b7cad5881" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_SAICGMACAutomotiveFinanceCompanyLimitedMember_01a11db6-d8fc-7b23-be92-4079431565da" xlink:href="acf-20260930.xsd#acf_SAICGMACAutomotiveFinanceCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_019fa4e7-d516-7db9-bf7d-63978f2d8840" xlink:to="loc_acf_SAICGMACAutomotiveFinanceCompanyLimitedMember_01a11db6-d8fc-7b23-be92-4079431565da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_01a11db5-fa0e-78e2-8d0a-f851489f7b3a" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_MinorityInterestTable_019fa4e7-d516-7e30-b59b-b9eb7b4881d0" xlink:to="loc_dei_LegalEntityAxis_01a11db5-fa0e-78e2-8d0a-f851489f7b3a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a11db5-fa0e-78e2-8d0a-f851489f7b3a_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_01a11db5-fa0e-78e2-8d0a-f851489f7b3a" xlink:to="loc_dei_EntityDomain_01a11db5-fa0e-78e2-8d0a-f851489f7b3a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_01a11db5-fa0e-76de-92c8-5a6985a6be1e" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_01a11db5-fa0e-78e2-8d0a-f851489f7b3a" xlink:to="loc_dei_EntityDomain_01a11db5-fa0e-76de-92c8-5a6985a6be1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_SAICGMACAutomotiveFinanceCompanyLimitedMember_01a11db6-4043-7fe2-97bf-88088c6465de" xlink:href="acf-20260930.xsd#acf_SAICGMACAutomotiveFinanceCompanyLimitedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_01a11db5-fa0e-76de-92c8-5a6985a6be1e" xlink:to="loc_acf_SAICGMACAutomotiveFinanceCompanyLimitedMember_01a11db6-4043-7fe2-97bf-88088c6465de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestAndFeeIncomeLoansConsumer_019fa4e7-d516-75a0-829f-ba76b9101be6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestAndFeeIncomeLoansConsumer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:to="loc_us-gaap_InterestAndFeeIncomeLoansConsumer_019fa4e7-d516-75a0-829f-ba76b9101be6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fa4e7-d516-7438-bcc4-db8c7cd5a72e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fa4e7-d516-7438-bcc4-db8c7cd5a72e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_019fa4e7-d516-7e46-ba52-a2c9239d69ee" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:to="loc_us-gaap_NetIncomeLoss_019fa4e7-d516-7e46-ba52-a2c9239d69ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UndistributedEarningsOfForeignSubsidiaries_019fa4e7-d516-7ea4-a7e1-81118ec305c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UndistributedEarningsOfForeignSubsidiaries"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:to="loc_us-gaap_UndistributedEarningsOfForeignSubsidiaries_019fa4e7-d516-7ea4-a7e1-81118ec305c4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCash_01a0ad99-31f0-790f-a4af-aa742af9154c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:to="loc_us-gaap_DividendsCash_01a0ad99-31f0-790f-a4af-aa742af9154c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsReceivable_01a0ada0-e472-7e28-bf78-bcd604387bdd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsReceivable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MinorityInterestLineItems_019fa4e7-d516-7cac-b1e3-21b0c56a3716" xlink:to="loc_us-gaap_DividendsReceivable_01a0ada0-e472-7e28-bf78-bcd604387bdd" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/DebtScheduleofDebtDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#DebtScheduleofDebtDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/DebtScheduleofDebtDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:href="acf-20260930.xsd#acf_ShortTermandLongTermDebtLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_ShortTermandLongTermDebtTable_019fa4e7-d516-7576-a9b3-8a31fcc2eaeb" xlink:href="acf-20260930.xsd#acf_ShortTermandLongTermDebtTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:to="loc_acf_ShortTermandLongTermDebtTable_019fa4e7-d516-7576-a9b3-8a31fcc2eaeb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-7781-a326-bbabe5ad19ba" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_ShortTermandLongTermDebtTable_019fa4e7-d516-7576-a9b3-8a31fcc2eaeb" xlink:to="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-7781-a326-bbabe5ad19ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7781-a326-bbabe5ad19ba_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-7781-a326-bbabe5ad19ba" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7781-a326-bbabe5ad19ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-740e-9b9b-855b7f1cb3b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-7781-a326-bbabe5ad19ba" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-740e-9b9b-855b7f1cb3b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019fa4e7-d516-7ffd-a6ba-e988fd991d35" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-740e-9b9b-855b7f1cb3b8" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019fa4e7-d516-7ffd-a6ba-e988fd991d35" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_SecuritizationNotesPayableMember_019fa4e7-d516-777d-8473-e724c556add4" xlink:href="acf-20260930.xsd#acf_SecuritizationNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-740e-9b9b-855b7f1cb3b8" xlink:to="loc_acf_SecuritizationNotesPayableMember_019fa4e7-d516-777d-8473-e724c556add4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019fa4e7-d516-7a23-88ec-cc71da9e700f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-740e-9b9b-855b7f1cb3b8" xlink:to="loc_us-gaap_SeniorNotesMember_019fa4e7-d516-7a23-88ec-cc71da9e700f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_OtherUnsecuredDebtMember_019fa4e7-d516-7b3a-a7a1-b936b88ef036" xlink:href="acf-20260930.xsd#acf_OtherUnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-740e-9b9b-855b7f1cb3b8" xlink:to="loc_acf_OtherUnsecuredDebtMember_019fa4e7-d516-7b3a-a7a1-b936b88ef036" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7ce4-8ef5-b0781b45c062" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_ShortTermandLongTermDebtTable_019fa4e7-d516-7576-a9b3-8a31fcc2eaeb" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7ce4-8ef5-b0781b45c062" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7ce4-8ef5-b0781b45c062_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7ce4-8ef5-b0781b45c062" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7ce4-8ef5-b0781b45c062_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77c0-b441-65593db3eec3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-7ce4-8ef5-b0781b45c062" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77c0-b441-65593db3eec3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-78e0-9624-41311712eb3c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77c0-b441-65593db3eec3" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-78e0-9624-41311712eb3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_019fa4e7-d516-7b8d-9cfb-88972fcc5151" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-77c0-b441-65593db3eec3" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_019fa4e7-d516-7b8d-9cfb-88972fcc5151" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebt_019fa4e7-d516-78a1-b2c0-cf30b2a2c910" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:to="loc_us-gaap_SecuredDebt_019fa4e7-d516-78a1-b2c0-cf30b2a2c910" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebt_019fa4e7-d516-7adf-b3da-3dfe388708fe" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnsecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:to="loc_us-gaap_UnsecuredDebt_019fa4e7-d516-7adf-b3da-3dfe388708fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_019fa4e7-d516-703e-b851-bf6995cd528c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:to="loc_us-gaap_LongTermDebt_019fa4e7-d516-703e-b851-bf6995cd528c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_SecuredDebtFairValueDisclosure_019fa4e7-d516-71a6-8ffa-fded636224a9" xlink:href="acf-20260930.xsd#acf_SecuredDebtFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:to="loc_acf_SecuredDebtFairValueDisclosure_019fa4e7-d516-71a6-8ffa-fded636224a9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_UnsecuredDebtFairValueDisclosure_019fa4e7-d516-76a4-9817-79b8950712b1" xlink:href="acf-20260930.xsd#acf_UnsecuredDebtFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:to="loc_acf_UnsecuredDebtFairValueDisclosure_019fa4e7-d516-76a4-9817-79b8950712b1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_019fa4e7-d516-7e88-aa40-7e3ef64a068e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_acf_ShortTermandLongTermDebtLineItems_019fa4e7-d516-7ad0-bcdd-46069e5ce9db" xlink:to="loc_us-gaap_LongTermDebtFairValue_019fa4e7-d516-7e88-aa40-7e3ef64a068e" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/DebtNarrativeDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#DebtNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/DebtNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_019fa4e7-d516-781f-a24f-094c368e215d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_DebtTable_019fa4e7-d516-79b9-abd5-1c649f6a0449" xlink:href="acf-20260930.xsd#acf_DebtTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019fa4e7-d516-781f-a24f-094c368e215d" xlink:to="loc_acf_DebtTable_019fa4e7-d516-79b9-abd5-1c649f6a0449" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-76f4-a8de-524ce336d5ef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_DebtTable_019fa4e7-d516-79b9-abd5-1c649f6a0449" xlink:to="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-76f4-a8de-524ce336d5ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-76f4-a8de-524ce336d5ef_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-76f4-a8de-524ce336d5ef" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-76f4-a8de-524ce336d5ef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7698-b027-c35a0b7777a1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_019fa4e7-d516-76f4-a8de-524ce336d5ef" xlink:to="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7698-b027-c35a0b7777a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_019fa4e7-d516-7dcd-a64b-af0aa66397b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_019fa4e7-d516-7698-b027-c35a0b7777a1" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_019fa4e7-d516-7dcd-a64b-af0aa66397b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-7c95-a708-4856525fd07d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_DebtTable_019fa4e7-d516-79b9-abd5-1c649f6a0449" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-7c95-a708-4856525fd07d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-7c95-a708-4856525fd07d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-7c95-a708-4856525fd07d" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-7c95-a708-4856525fd07d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-7bf3-99ac-f164f4a6dec8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_019fa4e7-d516-7c95-a708-4856525fd07d" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-7bf3-99ac-f164f4a6dec8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_019fa4e7-d516-70e9-acb0-4df051a3cbcc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-7bf3-99ac-f164f4a6dec8" xlink:to="loc_us-gaap_SecuredDebtMember_019fa4e7-d516-70e9-acb0-4df051a3cbcc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnsecuredDebtMember_019fa4e7-d516-75f5-8074-18ee5878383b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_UnsecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_019fa4e7-d516-7bf3-99ac-f164f4a6dec8" xlink:to="loc_us-gaap_UnsecuredDebtMember_019fa4e7-d516-75f5-8074-18ee5878383b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-77e3-85c5-a98e3e778a62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_acf_DebtTable_019fa4e7-d516-79b9-abd5-1c649f6a0449" xlink:to="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-77e3-85c5-a98e3e778a62" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-77e3-85c5-a98e3e778a62_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-77e3-85c5-a98e3e778a62" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-77e3-85c5-a98e3e778a62_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-7714-8101-97abbf1200b0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_019fa4e7-d516-77e3-85c5-a98e3e778a62" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-7714-8101-97abbf1200b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_SecuritizationNotesPayableMember_019fa4e7-d516-7c49-b229-377de0dfa591" xlink:href="acf-20260930.xsd#acf_SecuritizationNotesPayableMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-7714-8101-97abbf1200b0" xlink:to="loc_acf_SecuritizationNotesPayableMember_019fa4e7-d516-7c49-b229-377de0dfa591" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_019fa4e7-d516-709e-9429-036a2b85ceb5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_019fa4e7-d516-7714-8101-97abbf1200b0" xlink:to="loc_us-gaap_SeniorNotesMember_019fa4e7-d516-709e-9429-036a2b85ceb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019fa4e7-d516-7179-9eed-8931f34ccf83" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019fa4e7-d516-781f-a24f-094c368e215d" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_019fa4e7-d516-7179-9eed-8931f34ccf83" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_019fa4e7-d516-7288-8146-7c887429d522" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019fa4e7-d516-781f-a24f-094c368e215d" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_019fa4e7-d516-7288-8146-7c887429d522" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtWeightedAverageInterestRate_019fa4e7-d516-7083-8850-8bb2c6b00f92" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_019fa4e7-d516-781f-a24f-094c368e215d" xlink:to="loc_us-gaap_DebtWeightedAverageInterestRate_019fa4e7-d516-7083-8850-8bb2c6b00f92" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/VariableInterestEntitiesDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#VariableInterestEntitiesDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/VariableInterestEntitiesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7733-ba99-ac73402e80ac" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_VariableInterestEntityLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019fa4e7-d516-799f-8186-34aa3ca75c9b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfVariableInterestEntitiesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7733-ba99-ac73402e80ac" xlink:to="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019fa4e7-d516-799f-8186-34aa3ca75c9b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7374-938b-89e7d9e1f9fe" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfVariableInterestEntitiesTable_019fa4e7-d516-799f-8186-34aa3ca75c9b" xlink:to="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7374-938b-89e7d9e1f9fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7374-938b-89e7d9e1f9fe_default" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7374-938b-89e7d9e1f9fe" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7374-938b-89e7d9e1f9fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7e87-abae-842931eb1c4c" xlink:href="https://xbrl.fasb.org/srt/2026/elts/srt-2026.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_019fa4e7-d516-7374-938b-89e7d9e1f9fe" xlink:to="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7e87-abae-842931eb1c4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_VariableInterestEntityPrimaryBeneficiarySecuritizationandCreditFacilityVIEMember_019fa4e7-d516-7816-8be7-74686ddb6bf1" xlink:href="acf-20260930.xsd#acf_VariableInterestEntityPrimaryBeneficiarySecuritizationandCreditFacilityVIEMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_019fa4e7-d516-7e87-abae-842931eb1c4c" xlink:to="loc_acf_VariableInterestEntityPrimaryBeneficiarySecuritizationandCreditFacilityVIEMember_019fa4e7-d516-7816-8be7-74686ddb6bf1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedCashAndCashEquivalents_019fa4e7-d516-7ba6-8468-0716405cf0e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_RestrictedCashAndCashEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7733-ba99-ac73402e80ac" xlink:to="loc_us-gaap_RestrictedCashAndCashEquivalents_019fa4e7-d516-7ba6-8468-0716405cf0e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_019fa4e7-d516-73b4-856a-7a2e6a6689f3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7733-ba99-ac73402e80ac" xlink:to="loc_us-gaap_NotesReceivableNet_019fa4e7-d516-73b4-856a-7a2e6a6689f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_019fa4e7-d516-7224-9987-62f9c4bdbd44" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7733-ba99-ac73402e80ac" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_019fa4e7-d516-7224-9987-62f9c4bdbd44" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebt_019fa4e7-d516-7276-b243-1a9485493096" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SecuredDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableInterestEntityLineItems_019fa4e7-d516-7733-ba99-ac73402e80ac" xlink:to="loc_us-gaap_SecuredDebt_019fa4e7-d516-7276-b243-1a9485493096" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofFairValueDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofFairValueDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofFairValueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-733e-bbea-9590ec1ddd60_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-733e-bbea-9590ec1ddd60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7486-8ca4-b8f09d8232f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7486-8ca4-b8f09d8232f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-759e-b287-d51199b2645e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-759e-b287-d51199b2645e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-79c1-a92a-f0bdac817159" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-79c1-a92a-f0bdac817159" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a11045-7aef-7351-bddb-9bb65871f30b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a11045-7aef-7351-bddb-9bb65871f30b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-705a-b497-930e98efd8b9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-705a-b497-930e98efd8b9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-73ef-9c11-e279967ab006" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:to="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-73ef-9c11-e279967ab006" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-70dc-9723-12bf72e45a30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:to="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-70dc-9723-12bf72e45a30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-79b2-9f3e-3cb3f011159e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-79b2-9f3e-3cb3f011159e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7f72-8a77-99f356c94a23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7f72-8a77-99f356c94a23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c42-8f00-e78191afead7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7f72-8a77-99f356c94a23" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c42-8f00-e78191afead7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-7118-9034-d4621f8f6e51_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-7118-9034-d4621f8f6e51_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-785f-8129-87a335fd6c06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-785f-8129-87a335fd6c06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7d1b-9de6-1f095fb60a15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:to="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7d1b-9de6-1f095fb60a15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019fa4e7-d516-7be3-9e96-1e10e354f399" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfFinancialPositionLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_StatementOfFinancialPositionLocationBalanceAxis_019fa4e7-d516-7be3-9e96-1e10e354f399" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount_019fa4e7-d516-7770-98ba-a3c62ba8050f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeAssetNotionalAmount_019fa4e7-d516-7770-98ba-a3c62ba8050f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019fa4e7-d516-7953-8a72-59cce9af0381" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeAssets_019fa4e7-d516-7953-8a72-59cce9af0381" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019fa4e7-d516-7e25-a122-3386a0619d29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeLiabilities_019fa4e7-d516-7e25-a122-3386a0619d29" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_DerivativeAssetsLiabilitiesNetFairValueAmountNotOffsetAgainstCollateral_019fa4e7-d516-7428-83f8-8d18492b4bd5" xlink:href="acf-20260930.xsd#acf_DerivativeAssetsLiabilitiesNetFairValueAmountNotOffsetAgainstCollateral"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_acf_DerivativeAssetsLiabilitiesNetFairValueAmountNotOffsetAgainstCollateral_019fa4e7-d516-7428-83f8-8d18492b4bd5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019fa4e7-d516-7a0b-9095-5b8351108dfc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeCollateralObligationToReturnCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019fa4e7-d516-7a0b-9095-5b8351108dfc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_019fa4e7-d516-7a8d-a585-97b5fde23964" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_019fa4e7-d516-7a8d-a585-97b5fde23964" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofFairValueDetails_1" xlink:type="simple" xlink:href="acf-20260930.xsd#DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofFairValueDetails_1"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofFairValueDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-733e-bbea-9590ec1ddd60_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-733e-bbea-9590ec1ddd60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-733e-bbea-9590ec1ddd60" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7486-8ca4-b8f09d8232f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7486-8ca4-b8f09d8232f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-759e-b287-d51199b2645e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-759e-b287-d51199b2645e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-79c1-a92a-f0bdac817159" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-79c1-a92a-f0bdac817159" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a11045-7aef-7351-bddb-9bb65871f30b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-74dc-b0fb-95a616b0ac54" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a11045-7aef-7351-bddb-9bb65871f30b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-705a-b497-930e98efd8b9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-705a-b497-930e98efd8b9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-705a-b497-930e98efd8b9" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-73ef-9c11-e279967ab006" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:to="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-73ef-9c11-e279967ab006" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-70dc-9723-12bf72e45a30" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7101-8e89-1210f31566dc" xlink:to="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-70dc-9723-12bf72e45a30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-79b2-9f3e-3cb3f011159e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-79b2-9f3e-3cb3f011159e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7f72-8a77-99f356c94a23" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_019fa4e7-d516-79b2-9f3e-3cb3f011159e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7f72-8a77-99f356c94a23" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c42-8f00-e78191afead7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_019fa4e7-d516-7f72-8a77-99f356c94a23" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_019fa4e7-d516-7c42-8f00-e78191afead7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-74e1-8593-a84558a8cfbc" xlink:to="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-7118-9034-d4621f8f6e51_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-7118-9034-d4621f8f6e51_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-7118-9034-d4621f8f6e51" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-785f-8129-87a335fd6c06" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-785f-8129-87a335fd6c06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7d1b-9de6-1f095fb60a15" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-774a-a292-e5d05977acaa" xlink:to="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7d1b-9de6-1f095fb60a15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssetNotionalAmount_019fa4e7-d516-7770-98ba-a3c62ba8050f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssetNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeAssetNotionalAmount_019fa4e7-d516-7770-98ba-a3c62ba8050f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_019fa4e7-d516-7953-8a72-59cce9af0381" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeAssets_019fa4e7-d516-7953-8a72-59cce9af0381" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_019fa4e7-d516-7e25-a122-3386a0619d29" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeLiabilities_019fa4e7-d516-7e25-a122-3386a0619d29" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_DerivativeAssetsLiabilitiesNetFairValueAmountNotOffsetAgainstCollateral_019fa4e7-d516-7428-83f8-8d18492b4bd5" xlink:href="acf-20260930.xsd#acf_DerivativeAssetsLiabilitiesNetFairValueAmountNotOffsetAgainstCollateral"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_acf_DerivativeAssetsLiabilitiesNetFairValueAmountNotOffsetAgainstCollateral_019fa4e7-d516-7428-83f8-8d18492b4bd5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019fa4e7-d516-7a0b-9095-5b8351108dfc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeCollateralObligationToReturnCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeCollateralObligationToReturnCash_019fa4e7-d516-7a0b-9095-5b8351108dfc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_019fa4e7-d516-7a8d-a585-97b5fde23964" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-74c5-98e6-22143c53b284" xlink:to="loc_us-gaap_DerivativeLiabilityCollateralRightToReclaimCashOffset_019fa4e7-d516-7a8d-a585-97b5fde23964" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofBalanceSheetDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofBalanceSheetDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofBalanceSheetDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-73e6-9d2f-83b6b8586eb5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7806-a867-437e281ae440" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-73e6-9d2f-83b6b8586eb5" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7806-a867-437e281ae440" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-743e-bec3-c2368835cdc7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7806-a867-437e281ae440" xlink:to="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-743e-bec3-c2368835cdc7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-743e-bec3-c2368835cdc7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-743e-bec3-c2368835cdc7" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-743e-bec3-c2368835cdc7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-7c83-876e-c3ce7889f8e3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-743e-bec3-c2368835cdc7" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-7c83-876e-c3ce7889f8e3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-7e54-9bbb-5af7e837c08f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-7c83-876e-c3ce7889f8e3" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-7e54-9bbb-5af7e837c08f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-74d5-8e39-b2668033e5b8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7806-a867-437e281ae440" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-74d5-8e39-b2668033e5b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-74d5-8e39-b2668033e5b8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-74d5-8e39-b2668033e5b8" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-74d5-8e39-b2668033e5b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-756b-9f98-95f8445ad081" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-74d5-8e39-b2668033e5b8" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-756b-9f98-95f8445ad081" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-7fc1-ad35-3349f2b08c26" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-756b-9f98-95f8445ad081" xlink:to="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-7fc1-ad35-3349f2b08c26" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgedLiabilityFairValueHedge_019fa4e7-d516-7ae0-808d-89cae6ea3532" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgedLiabilityFairValueHedge"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-73e6-9d2f-83b6b8586eb5" xlink:to="loc_us-gaap_HedgedLiabilityFairValueHedge_019fa4e7-d516-7ae0-808d-89cae6ea3532" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_DerivativeLiabilityFairValueHedgingAdjustmentIncreaseDecrease_019fa4e7-d516-7f8e-ada6-b8141634ae9f" xlink:href="acf-20260930.xsd#acf_DerivativeLiabilityFairValueHedgingAdjustmentIncreaseDecrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-73e6-9d2f-83b6b8586eb5" xlink:to="loc_acf_DerivativeLiabilityFairValueHedgingAdjustmentIncreaseDecrease_019fa4e7-d516-7f8e-ada6-b8141634ae9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_DerivativeLiabilityFairValueHedgingAdjustmentIncreaseDecreaseDiscontinuationOfHedgeAccounting_019fa4e7-d516-71b3-82d4-45458dc9391a" xlink:href="acf-20260930.xsd#acf_DerivativeLiabilityFairValueHedgingAdjustmentIncreaseDecreaseDiscontinuationOfHedgeAccounting"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-73e6-9d2f-83b6b8586eb5" xlink:to="loc_acf_DerivativeLiabilityFairValueHedgingAdjustmentIncreaseDecreaseDiscontinuationOfHedgeAccounting_019fa4e7-d516-71b3-82d4-45458dc9391a" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofIncomeLossesRecognizedinIncomeDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofIncomeLossesRecognizedinIncomeDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofIncomeLossesRecognizedinIncomeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7dc0-926b-ec614b89be20_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7dc0-926b-ec614b89be20_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7613-a214-a5341f59103c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7613-a214-a5341f59103c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-75ee-8c4a-e2e26bd32225" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-75ee-8c4a-e2e26bd32225" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-7cf7-b400-fab7ca7b1f40" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-7cf7-b400-fab7ca7b1f40" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a11dc6-9156-75fe-bb53-94a31e442b8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a11dc6-9156-75fe-bb53-94a31e442b8a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7148-af3d-913b85b3810a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7148-af3d-913b85b3810a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-739b-aa96-d63374cc35f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:to="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-739b-aa96-d63374cc35f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-7241-9773-ac4ee50b0f2f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:to="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-7241-9773-ac4ee50b0f2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-72bf-becd-afc1ff011edf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-72bf-becd-afc1ff011edf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-7d7a-8a90-5b084fb126a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-7d7a-8a90-5b084fb126a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7add-a334-77b4760da384" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:to="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7add-a334-77b4760da384" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019fa4e7-d516-7878-ba8c-f1704c3a79c7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementOfIncomeLocationBalanceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_StatementOfIncomeLocationBalanceAxis_019fa4e7-d516-7878-ba8c-f1704c3a79c7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7249-a780-778582cf6f72_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7249-a780-778582cf6f72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fa4e7-d516-7bda-8907-73228f731178" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fa4e7-d516-7bda-8907-73228f731178" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fa4e7-d516-70c9-af9e-9a9a54b06407" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fa4e7-d516-70c9-af9e-9a9a54b06407" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fa4e7-d516-775a-b54d-a5d5778a07eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fa4e7-d516-775a-b54d-a5d5778a07eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_019fa4e7-d516-73cc-b043-b7cc4e40164d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_019fa4e7-d516-73cc-b043-b7cc4e40164d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_019fa4e7-d516-7e8a-a6b5-5ae0fe492eab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_019fa4e7-d516-7e8a-a6b5-5ae0fe492eab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019fa4e7-d516-7105-a3fa-c00c0d90214c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019fa4e7-d516-7105-a3fa-c00c0d90214c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_01a11dc6-9156-7fda-85a0-cd8590357bf5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_01a11dc6-9156-7fda-85a0-cd8590357bf5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_019fa4e7-d516-7589-9491-9afed5b7b571" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_019fa4e7-d516-7589-9491-9afed5b7b571" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fa4e7-d516-76b2-9820-111b7aff9e47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fa4e7-d516-76b2-9820-111b7aff9e47" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019fa4e7-d516-7900-8369-6e4499082b72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_OperatingExpenses_019fa4e7-d516-7900-8369-6e4499082b72" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsBeforeTaxParent_019fa4e7-d516-75da-8f5e-7eee7ce53f8d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsBeforeTaxParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsBeforeTaxParent_019fa4e7-d516-75da-8f5e-7eee7ce53f8d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019fa4e7-d516-7fae-a201-ffae1d7b08be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019fa4e7-d516-7fae-a201-ffae1d7b08be" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofIncomeLossesRecognizedinIncomeDetails_1" xlink:type="simple" xlink:href="acf-20260930.xsd#DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofIncomeLossesRecognizedinIncomeDetails_1"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/DerivativeFinancialInstrumentsandHedgingActivitiesScheduleofIncomeLossesRecognizedinIncomeDetails_1" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativesFairValueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7dc0-926b-ec614b89be20_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7dc0-926b-ec614b89be20_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_019fa4e7-d516-7dc0-926b-ec614b89be20" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7613-a214-a5341f59103c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_InterestRateSwapMember_019fa4e7-d516-7613-a214-a5341f59103c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-75ee-8c4a-e2e26bd32225" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_CurrencySwapMember_019fa4e7-d516-75ee-8c4a-e2e26bd32225" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-7cf7-b400-fab7ca7b1f40" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestRateContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_InterestRateContractMember_019fa4e7-d516-7cf7-b400-fab7ca7b1f40" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_01a11dc6-9156-75fe-bb53-94a31e442b8a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_019fa4e7-d516-7c20-87f6-8400a380f2cd" xlink:to="loc_us-gaap_ForeignExchangeContractMember_01a11dc6-9156-75fe-bb53-94a31e442b8a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7148-af3d-913b85b3810a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7148-af3d-913b85b3810a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingRelationshipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_019fa4e7-d516-7148-af3d-913b85b3810a" xlink:to="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-739b-aa96-d63374cc35f8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_FairValueHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:to="loc_us-gaap_FairValueHedgingMember_019fa4e7-d516-739b-aa96-d63374cc35f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-7241-9773-ac4ee50b0f2f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CashFlowHedgingMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingRelationshipDomain_019fa4e7-d516-7b4e-9126-c238f2d67013" xlink:to="loc_us-gaap_CashFlowHedgingMember_019fa4e7-d516-7241-9773-ac4ee50b0f2f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-72bf-becd-afc1ff011edf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-72bf-becd-afc1ff011edf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_019fa4e7-d516-72bf-becd-afc1ff011edf" xlink:to="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-7d7a-8a90-5b084fb126a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_019fa4e7-d516-7d7a-8a90-5b084fb126a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7add-a334-77b4760da384" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_019fa4e7-d516-76e0-b6c4-36a388c72cab" xlink:to="loc_us-gaap_NondesignatedMember_019fa4e7-d516-7add-a334-77b4760da384" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValuesDerivativesBalanceSheetLocationByDerivativeContractTypeByHedgingDesignationTable_019fa4e7-d516-7726-a44e-a72b291e37ae" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7249-a780-778582cf6f72_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7249-a780-778582cf6f72_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7249-a780-778582cf6f72" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fa4e7-d516-7bda-8907-73228f731178" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fa4e7-d516-7bda-8907-73228f731178" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fa4e7-d516-70c9-af9e-9a9a54b06407" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fa4e7-d516-70c9-af9e-9a9a54b06407" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fa4e7-d516-775a-b54d-a5d5778a07eb" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7e7f-a57a-c670e67a290b" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_019fa4e7-d516-775a-b54d-a5d5778a07eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_019fa4e7-d516-73cc-b043-b7cc4e40164d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1_019fa4e7-d516-73cc-b043-b7cc4e40164d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_019fa4e7-d516-7e8a-a6b5-5ae0fe492eab" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_019fa4e7-d516-7e8a-a6b5-5ae0fe492eab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019fa4e7-d516-7105-a3fa-c00c0d90214c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments_019fa4e7-d516-7105-a3fa-c00c0d90214c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_01a11dc6-9156-7fda-85a0-cd8590357bf5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_GainLossOnForeignCurrencyDerivativeInstrumentsNotDesignatedAsHedgingInstruments_01a11dc6-9156-7fda-85a0-cd8590357bf5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_019fa4e7-d516-7589-9491-9afed5b7b571" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_019fa4e7-d516-7589-9491-9afed5b7b571" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fa4e7-d516-76b2-9820-111b7aff9e47" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fa4e7-d516-76b2-9820-111b7aff9e47" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_019fa4e7-d516-7900-8369-6e4499082b72" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_OperatingExpenses_019fa4e7-d516-7900-8369-6e4499082b72" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsBeforeTaxParent_019fa4e7-d516-75da-8f5e-7eee7ce53f8d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsBeforeTaxParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseAfterAdjustmentsBeforeTaxParent_019fa4e7-d516-75da-8f5e-7eee7ce53f8d" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019fa4e7-d516-7fae-a201-ffae1d7b08be" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativesFairValueLineItems_019fa4e7-d516-7c8d-ba27-4c7c6a94785b" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_019fa4e7-d516-7fae-a201-ffae1d7b08be" xlink:type="arc" order="8"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/CommitmentsandContingenciesDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_019fa4e7-d516-78da-a6d5-139376650b52" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_019fa4e7-d516-7262-bd1d-23ceb01721cd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_019fa4e7-d516-78da-a6d5-139376650b52" xlink:to="loc_us-gaap_LossContingenciesTable_019fa4e7-d516-7262-bd1d-23ceb01721cd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsAxis_019fa4e7-d516-76f1-aee3-3d2dc0afcacd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_019fa4e7-d516-7262-bd1d-23ceb01721cd" xlink:to="loc_us-gaap_OtherCommitmentsAxis_019fa4e7-d516-76f1-aee3-3d2dc0afcacd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsDomain_019fa4e7-d516-76f1-aee3-3d2dc0afcacd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_OtherCommitmentsAxis_019fa4e7-d516-76f1-aee3-3d2dc0afcacd" xlink:to="loc_us-gaap_OtherCommitmentsDomain_019fa4e7-d516-76f1-aee3-3d2dc0afcacd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitmentsDomain_019fa4e7-d516-7dde-bf6d-099e87adbd8b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_OtherCommitmentsAxis_019fa4e7-d516-76f1-aee3-3d2dc0afcacd" xlink:to="loc_us-gaap_OtherCommitmentsDomain_019fa4e7-d516-7dde-bf6d-099e87adbd8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_ElectricVehiclesMember_019fa4e7-d516-7c88-b04c-330b5ddc1f1e" xlink:href="acf-20260930.xsd#acf_ElectricVehiclesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherCommitmentsDomain_019fa4e7-d516-7dde-bf6d-099e87adbd8b" xlink:to="loc_acf_ElectricVehiclesMember_019fa4e7-d516-7c88-b04c-330b5ddc1f1e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_IndirectTaxContingency_019fa4e7-d516-7824-98f4-ca0157dd41ac" xlink:href="acf-20260930.xsd#acf_IndirectTaxContingency"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019fa4e7-d516-78da-a6d5-139376650b52" xlink:to="loc_acf_IndirectTaxContingency_019fa4e7-d516-7824-98f4-ca0157dd41ac" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCommitment_019fa4e7-d516-72df-a2b5-3df5147107e5" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OtherCommitment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019fa4e7-d516-78da-a6d5-139376650b52" xlink:to="loc_us-gaap_OtherCommitment_019fa4e7-d516-72df-a2b5-3df5147107e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PurchaseCommitmentRemainingMinimumAmountCommitted_019fa4e7-d516-720f-853f-eb60e7e909d2" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PurchaseCommitmentRemainingMinimumAmountCommitted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_019fa4e7-d516-78da-a6d5-139376650b52" xlink:to="loc_us-gaap_PurchaseCommitmentRemainingMinimumAmountCommitted_019fa4e7-d516-720f-853f-eb60e7e909d2" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/ShareholdersEquityScheduleofCommonandPreferredStockDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#ShareholdersEquityScheduleofCommonandPreferredStockDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/ShareholdersEquityScheduleofCommonandPreferredStockDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7239-a7b0-f44d6ba5aef8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7239-a7b0-f44d6ba5aef8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-752e-abd2-80f14f0b32e1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7239-a7b0-f44d6ba5aef8" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-752e-abd2-80f14f0b32e1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-752e-abd2-80f14f0b32e1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-752e-abd2-80f14f0b32e1" xlink:to="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-752e-abd2-80f14f0b32e1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-78ba-a66f-4245af2c9b1b" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-752e-abd2-80f14f0b32e1" xlink:to="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-78ba-a66f-4245af2c9b1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_019fa4e7-d516-7d6c-94dd-58e59f068ef3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-78ba-a66f-4245af2c9b1b" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_019fa4e7-d516-7d6c-94dd-58e59f068ef3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_019fa4e7-d516-77f6-afd9-a864c6c4a277" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-78ba-a66f-4245af2c9b1b" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_019fa4e7-d516-77f6-afd9-a864c6c4a277" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesCPreferredStockMember_019fa4e7-d516-70a8-a697-555dea1c3041" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesCPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-78ba-a66f-4245af2c9b1b" xlink:to="loc_us-gaap_SeriesCPreferredStockMember_019fa4e7-d516-70a8-a697-555dea1c3041" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesAuthorized_019fa4e7-d516-71fe-ad72-76c7b13d8dcd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_CommonStockSharesAuthorized_019fa4e7-d516-71fe-ad72-76c7b13d8dcd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_019fa4e7-d516-7640-b616-dfba7039c2f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_CommonStockSharesIssued_019fa4e7-d516-7640-b616-dfba7039c2f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_019fa4e7-d516-70cd-8df7-1e214d7be340" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_019fa4e7-d516-70cd-8df7-1e214d7be340" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_019fa4e7-d516-7297-80ea-f9c2229cc412" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_019fa4e7-d516-7297-80ea-f9c2229cc412" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_019fa4e7-d516-72c2-8095-4a271b4325f1" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_PreferredStockSharesIssued_019fa4e7-d516-72c2-8095-4a271b4325f1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_019fa4e7-d516-7eca-a12b-e50e309b00d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_019fa4e7-d516-7eca-a12b-e50e309b00d6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockLiquidationPreference_019fa4e7-d516-750d-8768-5ba8b5ffda45" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PreferredStockLiquidationPreference"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-77f4-b4c9-f006c70427e9" xlink:to="loc_us-gaap_PreferredStockLiquidationPreference_019fa4e7-d516-750d-8768-5ba8b5ffda45" xlink:type="arc" order="6"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/ShareholdersEquityNarrativeDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#ShareholdersEquityNarrativeDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/ShareholdersEquityNarrativeDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-782a-bd59-5c53ffedf6c0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7e74-b347-92aa11c204a6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-782a-bd59-5c53ffedf6c0" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7e74-b347-92aa11c204a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-777d-ad4a-14a013a262f4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7e74-b347-92aa11c204a6" xlink:to="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-777d-ad4a-14a013a262f4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-777d-ad4a-14a013a262f4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-777d-ad4a-14a013a262f4" xlink:to="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-777d-ad4a-14a013a262f4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-75be-ba37-5f093dd339a7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_019fa4e7-d516-777d-ad4a-14a013a262f4" xlink:to="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-75be-ba37-5f093dd339a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_019fa4e7-d516-74f6-97e0-96a63c3aabf6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-75be-ba37-5f093dd339a7" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_019fa4e7-d516-74f6-97e0-96a63c3aabf6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesBPreferredStockMember_019fa4e7-d516-7696-bee3-974e1e2bb617" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-75be-ba37-5f093dd339a7" xlink:to="loc_us-gaap_SeriesBPreferredStockMember_019fa4e7-d516-7696-bee3-974e1e2bb617" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesCPreferredStockMember_019fa4e7-d516-7734-afd7-a51c7536dbd4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SeriesCPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_019fa4e7-d516-75be-ba37-5f093dd339a7" xlink:to="loc_us-gaap_SeriesCPreferredStockMember_019fa4e7-d516-7734-afd7-a51c7536dbd4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStock_019fa4e7-d516-7c85-bbb3-a27c0bf0d4d6" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_DividendsCommonStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-782a-bd59-5c53ffedf6c0" xlink:to="loc_us-gaap_DividendsCommonStock_019fa4e7-d516-7c85-bbb3-a27c0bf0d4d6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_019fa4e7-d516-7d39-a0c9-0b3d1ebc7e62" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-782a-bd59-5c53ffedf6c0" xlink:to="loc_us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock_019fa4e7-d516-7d39-a0c9-0b3d1ebc7e62" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/ShareholdersEquityScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#ShareholdersEquityScheduleofAccumulatedOtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/ShareholdersEquityScheduleofAccumulatedOtherComprehensiveIncomeLossDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-7902-9530-033698836ca7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ClassOfStockLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7b95-9d78-6fcaeb6f2750" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfStockByClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-7902-9530-033698836ca7" xlink:to="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7b95-9d78-6fcaeb6f2750" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7bd5-8e4f-01b98b3dabc9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfStockByClassTable_019fa4e7-d516-7b95-9d78-6fcaeb6f2750" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7bd5-8e4f-01b98b3dabc9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7bd5-8e4f-01b98b3dabc9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7bd5-8e4f-01b98b3dabc9" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7bd5-8e4f-01b98b3dabc9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7c4c-94f2-4a6aacc2408f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_019fa4e7-d516-7bd5-8e4f-01b98b3dabc9" xlink:to="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7c4c-94f2-4a6aacc2408f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fa4e7-d516-759b-bb47-f38cc0584310" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7c4c-94f2-4a6aacc2408f" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_019fa4e7-d516-759b-bb47-f38cc0584310" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fa4e7-d516-7d2b-aa89-52486754d791" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_019fa4e7-d516-7c4c-94f2-4a6aacc2408f" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_019fa4e7-d516-7d2b-aa89-52486754d791" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019fa4e7-d516-784e-ad35-1c3dbd7222a8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockLineItems_019fa4e7-d516-7902-9530-033698836ca7" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019fa4e7-d516-784e-ad35-1c3dbd7222a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019fa4e7-d516-751c-8204-397ef391d656" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019fa4e7-d516-784e-ad35-1c3dbd7222a8" xlink:to="loc_us-gaap_StockholdersEquity_019fa4e7-d516-751c-8204-397ef391d656" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019fa4e7-d516-77cd-a3ef-3f99953dbafd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_019fa4e7-d516-784e-ad35-1c3dbd7222a8" xlink:to="loc_us-gaap_OciBeforeReclassificationsNetOfTaxAttributableToParent_019fa4e7-d516-77cd-a3ef-3f99953dbafd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_019fa4e7-d516-7b3c-9163-f8a36d6984fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StockholdersEquity"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/SegmentReportingScheduleofOperationsReportingbyRevenueDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#SegmentReportingScheduleofOperationsReportingbyRevenueDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/SegmentReportingScheduleofOperationsReportingbyRevenueDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-76b1-8d1a-d1801b5f0348" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fa4e7-d516-7464-8aa6-12b478128343" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-76b1-8d1a-d1801b5f0348" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fa4e7-d516-7464-8aa6-12b478128343" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7cb5-b957-1686179d59c4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fa4e7-d516-7464-8aa6-12b478128343" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7cb5-b957-1686179d59c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fa4e7-d516-7cb5-b957-1686179d59c4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7cb5-b957-1686179d59c4" xlink:to="loc_us-gaap_SegmentDomain_019fa4e7-d516-7cb5-b957-1686179d59c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fa4e7-d516-7f1a-a0b6-bbc1fdde47e9" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7cb5-b957-1686179d59c4" xlink:to="loc_us-gaap_SegmentDomain_019fa4e7-d516-7f1a-a0b6-bbc1fdde47e9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember_019fa4e7-d516-75f1-87b7-b8e0762abb95" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fa4e7-d516-7f1a-a0b6-bbc1fdde47e9" xlink:to="loc_us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember_019fa4e7-d516-75f1-87b7-b8e0762abb95" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_NorthAmericaSegmentMember_019fa4e7-d516-7b79-b4d7-f1cf13f4ef85" xlink:href="acf-20260930.xsd#acf_NorthAmericaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember_019fa4e7-d516-75f1-87b7-b8e0762abb95" xlink:to="loc_acf_NorthAmericaSegmentMember_019fa4e7-d516-7b79-b4d7-f1cf13f4ef85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_InternationalSegmentMember_019fa4e7-d516-74b1-8bf2-04602a2831c5" xlink:href="acf-20260930.xsd#acf_InternationalSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReportableSegmentAggregationBeforeOtherOperatingSegmentMember_019fa4e7-d516-75f1-87b7-b8e0762abb95" xlink:to="loc_acf_InternationalSegmentMember_019fa4e7-d516-74b1-8bf2-04602a2831c5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllOtherSegmentsMember_019fa4e7-d516-718d-b55c-37538867570c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllOtherSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fa4e7-d516-7f1a-a0b6-bbc1fdde47e9" xlink:to="loc_us-gaap_AllOtherSegmentsMember_019fa4e7-d516-718d-b55c-37538867570c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Revenues_019fa4e7-d516-748a-bbc6-69fa9b7923d4" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Revenues"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-76b1-8d1a-d1801b5f0348" xlink:to="loc_us-gaap_Revenues_019fa4e7-d516-748a-bbc6-69fa9b7923d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CostsAndExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-76b1-8d1a-d1801b5f0348" xlink:to="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LaborAndRelatedExpense_019fa4e7-d516-7b1a-87e3-3cc25f52ceef" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_LaborAndRelatedExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:to="loc_us-gaap_LaborAndRelatedExpense_019fa4e7-d516-7b1a-87e3-3cc25f52ceef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease_019fa4e7-d516-7e40-a909-8cebcdd093ff" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:to="loc_us-gaap_OperatingLeasesIncomeStatementDepreciationExpenseOnPropertySubjectToOrHeldForLease_019fa4e7-d516-7e40-a909-8cebcdd093ff" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnTerminationOfLease_019fa4e7-d516-700a-9402-f74a07df71b3" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_GainLossOnTerminationOfLease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:to="loc_us-gaap_GainLossOnTerminationOfLease_019fa4e7-d516-700a-9402-f74a07df71b3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForLoanLossesExpensed_019fa4e7-d516-7afc-bafa-35ffb25c21fd" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ProvisionForLoanLossesExpensed"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:to="loc_us-gaap_ProvisionForLoanLossesExpensed_019fa4e7-d516-7afc-bafa-35ffb25c21fd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpenseNonoperating_019fa4e7-d516-725a-aad3-fd7057ccd007" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_InterestExpenseNonoperating"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:to="loc_us-gaap_InterestExpenseNonoperating_019fa4e7-d516-725a-aad3-fd7057ccd007" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PolicyholderBenefitsAndClaimsIncurredNet_019fa4e7-d516-73aa-be48-b83719419b5e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PolicyholderBenefitsAndClaimsIncurredNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostsAndExpensesAbstract_019fa4e7-d516-7588-bbe2-5ffc94bfbf8c" xlink:to="loc_us-gaap_PolicyholderBenefitsAndClaimsIncurredNet_019fa4e7-d516-73aa-be48-b83719419b5e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingOtherItemAmount_019fa4e7-d516-783d-96a2-2929779b82da" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingOtherItemAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-76b1-8d1a-d1801b5f0348" xlink:to="loc_us-gaap_SegmentReportingOtherItemAmount_019fa4e7-d516-783d-96a2-2929779b82da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019fa4e7-d516-76ed-8661-8a6888b2b54f" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromEquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-76b1-8d1a-d1801b5f0348" xlink:to="loc_us-gaap_IncomeLossFromEquityMethodInvestments_019fa4e7-d516-76ed-8661-8a6888b2b54f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fa4e7-d516-7626-9c50-f937742a10e0" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-76b1-8d1a-d1801b5f0348" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_019fa4e7-d516-7626-9c50-f937742a10e0" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/SegmentReportingScheduleofOperationsReportingbyAssetsDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#SegmentReportingScheduleofOperationsReportingbyAssetsDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/SegmentReportingScheduleofOperationsReportingbyAssetsDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-7b47-9179-0601b70553e8" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fa4e7-d516-7ae5-92a7-fe6bb03cda61" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-7b47-9179-0601b70553e8" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fa4e7-d516-7ae5-92a7-fe6bb03cda61" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7b0a-9c17-c22fbc0786ed" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fa4e7-d516-7ae5-92a7-fe6bb03cda61" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7b0a-9c17-c22fbc0786ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fa4e7-d516-7b0a-9c17-c22fbc0786ed_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7b0a-9c17-c22fbc0786ed" xlink:to="loc_us-gaap_SegmentDomain_019fa4e7-d516-7b0a-9c17-c22fbc0786ed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_019fa4e7-d516-765c-b45c-6c66da289e26" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_019fa4e7-d516-7b0a-9c17-c22fbc0786ed" xlink:to="loc_us-gaap_SegmentDomain_019fa4e7-d516-765c-b45c-6c66da289e26" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_NorthAmericaSegmentMember_019fa4e7-d516-7abf-9096-2ab41e04b0a4" xlink:href="acf-20260930.xsd#acf_NorthAmericaSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fa4e7-d516-765c-b45c-6c66da289e26" xlink:to="loc_acf_NorthAmericaSegmentMember_019fa4e7-d516-7abf-9096-2ab41e04b0a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_InternationalSegmentMember_019fa4e7-d516-70bf-bf45-4e7f6b5bc3db" xlink:href="acf-20260930.xsd#acf_InternationalSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_019fa4e7-d516-765c-b45c-6c66da289e26" xlink:to="loc_acf_InternationalSegmentMember_019fa4e7-d516-70bf-bf45-4e7f6b5bc3db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsAxis_019fa4e7-d516-795c-b23b-70e29a475734" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_019fa4e7-d516-7ae5-92a7-fe6bb03cda61" xlink:to="loc_us-gaap_SubsegmentsAxis_019fa4e7-d516-795c-b23b-70e29a475734" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_019fa4e7-d516-795c-b23b-70e29a475734_default" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsegmentsAxis_019fa4e7-d516-795c-b23b-70e29a475734" xlink:to="loc_us-gaap_SubsegmentsDomain_019fa4e7-d516-795c-b23b-70e29a475734_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsegmentsDomain_019fa4e7-d516-7d45-a103-b6a971cfc774" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_SubsegmentsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsegmentsAxis_019fa4e7-d516-795c-b23b-70e29a475734" xlink:to="loc_us-gaap_SubsegmentsDomain_019fa4e7-d516-7d45-a103-b6a971cfc774" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllOtherSegmentsMember_019fa4e7-d516-7ceb-a3ec-309031f0f5d7" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_AllOtherSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsegmentsDomain_019fa4e7-d516-7d45-a103-b6a971cfc774" xlink:to="loc_us-gaap_AllOtherSegmentsMember_019fa4e7-d516-7ceb-a3ec-309031f0f5d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NotesReceivableNet_019fa4e7-d516-7b2b-be75-fb30f7b3f79c" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_NotesReceivableNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-7b47-9179-0601b70553e8" xlink:to="loc_us-gaap_NotesReceivableNet_019fa4e7-d516-7b2b-be75-fb30f7b3f79c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_019fa4e7-d516-7408-85b3-bdd7660f4a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-7b47-9179-0601b70553e8" xlink:to="loc_us-gaap_PropertySubjectToOrAvailableForOperatingLeaseNet_019fa4e7-d516-7408-85b3-bdd7660f4a9e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_AssetsFromReportableSegments_019fa4e7-d516-779a-8317-78af1945d858" xlink:href="acf-20260930.xsd#acf_AssetsFromReportableSegments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-7b47-9179-0601b70553e8" xlink:to="loc_acf_AssetsFromReportableSegments_019fa4e7-d516-779a-8317-78af1945d858" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_SegmentReportingOtherSegmentItemOtherAssets_019fa4e7-d516-740a-b8ed-787dc96fa22c" xlink:href="acf-20260930.xsd#acf_SegmentReportingOtherSegmentItemOtherAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-7b47-9179-0601b70553e8" xlink:to="loc_acf_SegmentReportingOtherSegmentItemOtherAssets_019fa4e7-d516-740a-b8ed-787dc96fa22c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019fa4e7-d516-733e-8580-1805a8ce1197" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_019fa4e7-d516-7b47-9179-0601b70553e8" xlink:to="loc_us-gaap_Assets_019fa4e7-d516-733e-8580-1805a8ce1197" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://www.gmfinancial.com/role/RegulatoryCapitalandOtherRegulatoryMattersDetails" xlink:type="simple" xlink:href="acf-20260930.xsd#RegulatoryCapitalandOtherRegulatoryMattersDetails"/>
  <link:definitionLink xlink:role="http://www.gmfinancial.com/role/RegulatoryCapitalandOtherRegulatoryMattersDetails" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsLineItems_019fa4e7-d516-7dd1-a26f-88c3e6f9078d" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsTable_019fa4e7-d516-73aa-be9b-ac2efe25e187" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsLineItems_019fa4e7-d516-7dd1-a26f-88c3e6f9078d" xlink:to="loc_us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsTable_019fa4e7-d516-73aa-be9b-ac2efe25e187" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_019fa4e7-d516-780b-b769-0b8c5ff6b80c" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsTable_019fa4e7-d516-73aa-be9b-ac2efe25e187" xlink:to="loc_dei_LegalEntityAxis_019fa4e7-d516-780b-b769-0b8c5ff6b80c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019fa4e7-d516-780b-b769-0b8c5ff6b80c_default" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_019fa4e7-d516-780b-b769-0b8c5ff6b80c" xlink:to="loc_dei_EntityDomain_019fa4e7-d516-780b-b769-0b8c5ff6b80c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_019fa4e7-d516-7699-a7b3-e965d72404e6" xlink:href="https://xbrl.sec.gov/dei/2026/dei-2026.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_019fa4e7-d516-780b-b769-0b8c5ff6b80c" xlink:to="loc_dei_EntityDomain_019fa4e7-d516-7699-a7b3-e965d72404e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_acf_InternationalRegulatedBankAndFinanceCompaniesMember_019fa4e7-d516-73ab-a86a-070b30bc96ad" xlink:href="acf-20260930.xsd#acf_InternationalRegulatedBankAndFinanceCompaniesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_019fa4e7-d516-7699-a7b3-e965d72404e6" xlink:to="loc_acf_InternationalRegulatedBankAndFinanceCompaniesMember_019fa4e7-d516-73ab-a86a-070b30bc96ad" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_019fa4e7-d516-7947-ba09-f8c39ff3e8dc" xlink:href="https://xbrl.fasb.org/us-gaap/2026/elts/us-gaap-2026.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CapitalRequirementsOnForeignFinancialInstitutionsLineItems_019fa4e7-d516-7dd1-a26f-88c3e6f9078d" xlink:to="loc_us-gaap_Assets_019fa4e7-d516-7947-ba09-f8c39ff3e8dc" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
