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Cadillac U2A91

In some cases, these DTC's will not be set. Cause This condition may be caused if the VIN or mileage fails to w

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Cadillac dealer or qualified Cadillac/GM service facility for diagnosis. The supplied evidence does not establish a customer-performed repair.
Confidence95%

Quick answer

For certain 2023–2025 Cadillac LYRIQ vehicles in the U.S., DTC U2A91 is referenced in GM/Cadillac bulletin PIT5851F in connection with a condition involving zero or incorrect displayed mileage. The supplied evidence says the condition may occur if VIN or mileage information fails to write, but the provided excerpt is truncated and does not establish the complete cause, repair, or driving/charging impact.

This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.

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1. What does U2A91 mean?

For certain 2023–2025 Cadillac LYRIQ vehicles in the U.S., DTC U2A91 is referenced in GM/Cadillac bulletin PIT5851F in connection with a condition involving zero or incorrect displayed mileage. The supplied evidence says the condition may occur if VIN or mileage information fails to write, but the provided excerpt is truncated and does not establish the complete cause, repair, or driving/charging impact.

2. Technical explanation

NHTSA manufacturer communication PIT5851F, published April 4, 2025, lists U2A91 among DTCs that may be current with a zero-mile or incorrect-mileage condition. The bulletin excerpt also states that, in some cases, these DTCs will not be set. It further says the condition may be caused if the VIN or mileage fails to write; however, the supplied verified evidence ends mid-sentence, so the complete technical mechanism is not established.

3. What system is affected?

Not yet established by verified evidence. The verified bulletin excerpt concerns VIN or mileage information and a zero-mile or incorrect-mileage condition.

4. How serious is this code?

Unknown. The supplied verified evidence does not assign a severity level or describe a safety consequence.

5. Symptoms you may notice

  • Zero miles displayed or incorrect mileage.
  • U2A91 may be current.
  • The relevant DTCs may not be set in some cases.

6. Possible causes

  • The bulletin states that the condition may be caused if VIN or mileage information fails to write. The complete cause statement is not available in the supplied evidence.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Record the displayed mileage condition and any diagnostic codes present.
  • Arrange Cadillac service evaluation, particularly if the vehicle displays zero or incorrect mileage.
  • Do not attempt high-voltage or module repair procedures based on this information.

10. Step-by-step troubleshooting

  1. Confirm whether the vehicle is a 2023–2025 Cadillac LYRIQ in the U.S.
  2. Document whether mileage is displayed as zero or appears incorrect.
  3. Have a qualified service facility check for current DTC U2A91 and the other codes referenced by PIT5851F.
  4. Review Cadillac/GM bulletin PIT5851F using the vehicle VIN and current service information.

11. When to contact service

Contact a Cadillac dealer or qualified Cadillac/GM service facility for diagnosis. The supplied evidence does not establish a customer-performed repair.

12. What the service center may check

  • Verify the reported zero-mile or incorrect-mileage condition.
  • Check whether U2A91 is current.
  • Check for other DTCs listed in PIT5851F.
  • Determine whether VIN or mileage information failed to write, consistent with the bulletin excerpt.
  • Use the complete applicable GM/Cadillac service information and bulletin procedure; the supplied excerpt does not provide the repair procedure.

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied bulletin excerpt does not include a verified repair or resolution.

14. Affected vehicles

15. Related TSBs / service bulletins

  • PIT5851F — NHTSA Manufacturer Communication PDF 11016674, published April 4, 2025. It references U2A91 in relation to zero or incorrect mileage and states that DTCs may not be set in some cases. Applicability supplied: 2023–2025 Cadillac LYRIQ, U.S.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official source: NHTSA Manufacturer Communication PDF 11016674, PIT5851F: https://static.nhtsa.gov/odi/tsbs/2025/MC-11016674-0001.pdf

19. Frequently asked questions

What does U2A91 mean for a Cadillac LYRIQ?

In the supplied official bulletin excerpt, U2A91 is one of several DTCs that may be current when the vehicle has zero or incorrect mileage. A complete code definition is not established by the provided evidence.

Can U2A91 appear without a mileage issue?

Not yet established by verified evidence.

Can a mileage issue occur without U2A91?

Yes. PIT5851F states that, in some cases, the referenced DTCs will not be set.

Is there a verified fix?

Not yet established by verified evidence because the supplied bulletin excerpt does not contain the repair procedure.

20. Sources & verification

Verified
Cadillac U2A91: In some cases, these DTC's will not be set. Cause This… | EV Diagnostics