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Chevrolet U0131

If the entire bus is impacted (multiple ECUs with comm loss). • Do not replace the front camera. • Diagnose the CAN Bus 2

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceService evaluation is appropriate because the verified bulletin directs diagnosis of CAN Bus 2 for the described multi-ECU communication-loss condition.
Confidence95%

Quick answer

For specified U.S. Chevrolet Blazer and Equinox vehicles, verified GM/NHTSA service-bulletin evidence says that when U0131 occurs as part of an entire CAN Bus 2 communication loss affecting multiple ECUs, the front camera should not be replaced; CAN Bus 2 should be diagnosed.

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 U0131 mean?

For specified U.S. Chevrolet Blazer and Equinox vehicles, verified GM/NHTSA service-bulletin evidence says that when U0131 occurs as part of an entire CAN Bus 2 communication loss affecting multiple ECUs, the front camera should not be replaced; CAN Bus 2 should be diagnosed.

2. Technical explanation

U0131 is cited in GM bulletin PIT6503/PIT6503A/PIT6503B as an example of a loss-of-communication DTC that may be set by the K56 Serial Data Gateway Module against other ECUs on CAN Bus 2. The bulletin distinguishes an entire-bus condition, described as multiple ECUs with communication loss. For that condition, the bulletin directs technicians not to replace the B174W Front View Camera module and to diagnose CAN Bus 2.

3. What system is affected?

CAN Bus 2 serial-data communications. The verified bulletin evidence also references the K56 Serial Data Gateway Module and the B174W Front View Camera module.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • Multiple ECUs with loss-of-communication conditions on CAN Bus 2, when the entire bus is impacted.

6. Possible causes

  • An entire CAN Bus 2 communication issue is indicated for diagnosis when multiple ECUs have communication loss. The specific underlying cause is not yet established by verified 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

  • Have the vehicle assessed by a qualified Chevrolet/GM service technician using the applicable diagnostic information.
  • Do not assume the B174W Front View Camera module requires replacement when multiple ECUs are affected by CAN Bus 2 communication loss.

10. Step-by-step troubleshooting

  1. Confirm whether the K56 Serial Data Gateway Module is setting loss-of-communication DTCs for other ECUs on CAN Bus 2.
  2. If multiple ECUs have communication loss and the entire bus is impacted, diagnose CAN Bus 2.
  3. Do not replace the B174W Front View Camera module for the verified entire-bus condition described in PIT6503-series bulletins.

11. When to contact service

Service evaluation is appropriate because the verified bulletin directs diagnosis of CAN Bus 2 for the described multi-ECU communication-loss condition.

12. What the service center may check

  • Check whether the K56 Serial Data Gateway Module is also setting loss-of-communication DTCs against other ECUs on CAN Bus 2.
  • Determine whether the condition affects the entire bus, with multiple ECUs reporting communication loss.
  • Diagnose CAN Bus 2 if the entire bus is impacted.

13. Possible repair or resolution

  • For the verified condition of multiple ECUs with communication loss across CAN Bus 2, do not replace the B174W Front View Camera module solely on that basis.
  • Diagnose CAN Bus 2. The final repair is not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • GM PIT6503B, published June 17, 2026; NHTSA manufacturer communication MC-11034014-0001.
  • GM PIT6503A, published June 3, 2026; NHTSA manufacturer communication MC-11033726-0001.
  • GM PIT6503, published April 14, 2026; NHTSA manufacturer communication MC-11031514-0001.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official NHTSA-hosted manufacturer communication: PIT6503B, https://static.nhtsa.gov/odi/tsbs/2026/MC-11034014-0001.pdf. Earlier related versions: PIT6503A, https://static.nhtsa.gov/odi/tsbs/2026/MC-11033726-0001.pdf; PIT6503, https://static.nhtsa.gov/odi/tsbs/2026/MC-11031514-0001.pdf. Verified applicability: U.S. Chevrolet Blazer, model years 2024–2026; U.S. Chevrolet Equinox, model years 2024–2026. The supplied applicability data also separately lists Equinox model years 2025–2026.

19. Frequently asked questions

Does U0131 mean the front camera should be replaced?

No, not for the verified condition in which multiple ECUs have communication loss and the entire CAN Bus 2 is impacted. PIT6503-series bulletins say not to replace the B174W Front View Camera module and to diagnose CAN Bus 2.

What should be diagnosed when multiple ECUs have communication loss?

The verified bulletin direction is to diagnose CAN Bus 2.

Which vehicles are covered by the supplied evidence?

The supplied applicability evidence covers U.S. Chevrolet Blazer model years 2024–2026 and U.S. Chevrolet Equinox model years 2024–2026.

Is it safe to drive or charge with U0131?

Not yet established by verified evidence.

20. Sources & verification

ReferenceVerified
Chevrolet U0131: If the entire bus is impacted (multiple ECUs with… | EV Diagnostics