Exhibit 31.1



I, Susan B. Sheffield, certify that:



| | 1. | I have reviewed this report on Form 10-K and all reports on Form 10-D required to be filed in respect of the period covered by this
report on Form 10-K of GM Financial Consumer Automobile Receivables Trust 2018-3 (the “Exchange Act periodic reports”);
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| | 2. | Based on my knowledge, the Exchange Act periodic reports, taken as a whole, do not contain any untrue statement of a material fact
or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were
made, not misleading with respect to the period covered by this report;
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| | 3. | Based on my knowledge, all of the distribution, servicing and other information required to be provided under Form 10-D for the period
covered by this report is included in the Exchange Act periodic reports;
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| | 4. | Based on my knowledge and the servicer compliance statement required in this report under Item 1123 of Regulation AB, and except as
disclosed in the Exchange Act periodic reports, the servicer has fulfilled its obligations under the servicing agreements in all material
respects; and
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| | 5. | All of the reports on assessment of compliance with servicing criteria for asset-backed securities and their related attestation reports
on assessment of compliance with servicing criteria for asset-backed securities required to be included in this report in accordance with
Item 1122 of Regulation AB and Exchange Act Rules 13a-18 and 15d-18 have been included as an exhibit to this report, except as otherwise
disclosed in this report. Any material instances of noncompliance described in such reports have been disclosed in this report on Form
10-K.
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In giving the certifications above, I have reasonably relied on information
provided to me by the following unaffiliated parties: The Bank of New York Mellon.



|By:    | /s/ Susan B. Sheffield                                | 
|------ | ----------------------------------------------------- | 
|Name:  | Susan B. Sheffield                                    | 
|Title: | Executive Vice President and 
Chief Financial Officer | 
|Date:  | March 4, 2022                                         |