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Honda U357C

If all of these DTCs are NOT SET as current or history, this bulletin does not apply; continue with normal trou

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceService support is appropriate if U357C is present, particularly to verify whether the complete DTC set required by Honda bulletin A25-043 is stored as current or history. Further service urgency is not established by the supplied evidence.
Confidence95%

Quick answer

For certain 2024–2025 Honda Prologue vehicles in the U.S., DTC U357C is included in Honda bulletin A25-043 only when it is present together with all listed companion DTCs as current or history codes. If all listed DTCs are not set, the bulletin does not apply and normal troubleshooting should continue.

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 U357C mean?

For certain 2024–2025 Honda Prologue vehicles in the U.S., DTC U357C is included in Honda bulletin A25-043 only when it is present together with all listed companion DTCs as current or history codes. If all listed DTCs are not set, the bulletin does not apply and normal troubleshooting should continue.

2. Technical explanation

Verified evidence identifies U357C as one of the DTCs referenced in NHTSA-posted Honda manufacturer communication A25-043. The supplied bulletin excerpt requires verification that the vehicle has all of the following DTCs set: P2C8A, P2C8B, U3577, U3578, U3579, U357A, U357B, U357C, U357D, U357E, and U35AF. The excerpt states that if all of these DTCs are not set as current or history, the bulletin does not apply and normal troubleshooting should continue. The supplied evidence does not establish a standalone technical definition, subsystem, cause, or repair for U357C.

3. What system is affected?

Not yet established by verified evidence.

4. How serious is this code?

Unknown. The supplied verified evidence does not provide a severity classification.

5. Symptoms you may notice

  • Not yet established by verified evidence.

6. Possible causes

  • 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’s diagnostic trouble codes checked and determine whether every DTC listed in Honda bulletin A25-043 is present as a current or history code.
  • If the complete listed DTC set is not present, follow normal troubleshooting as directed by the bulletin excerpt.
  • Do not infer a repair or high-voltage procedure from U357C alone; none is established by the supplied evidence.

10. Step-by-step troubleshooting

  1. Verify whether P2C8A, P2C8B, U3577, U3578, U3579, U357A, U357B, U357C, U357D, U357E, and U35AF are all set as current or history DTCs.
  2. If all listed DTCs are not set, Honda bulletin A25-043 does not apply; continue with normal troubleshooting.

11. When to contact service

Service support is appropriate if U357C is present, particularly to verify whether the complete DTC set required by Honda bulletin A25-043 is stored as current or history. Further service urgency is not established by the supplied evidence.

12. What the service center may check

  • Read current and history DTCs.
  • Confirm whether all DTCs required by bulletin A25-043 are present: P2C8A, P2C8B, U3577, U3578, U3579, U357A, U357B, U357C, U357D, U357E, and U35AF.

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied excerpt refers to inspection and repair procedures but does not provide the procedure or repair outcome.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Honda bulletin A25-043, published in an NHTSA manufacturer communication dated May 23, 2025, applies only after verifying that all of these DTCs are set as current or history: P2C8A, P2C8B, U3577, U3578, U3579, U357A, U357B, U357C, U357D, U357E, and U35AF.
  • If all listed DTCs are not set as current or history, the bulletin does not apply and normal troubleshooting should continue.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official source: NHTSA Manufacturer Communication PDF 11019250, Honda bulletin A25-043, published May 23, 2025: https://static.nhtsa.gov/odi/tsbs/2025/MC-11019250-0001.pdf

19. Frequently asked questions

What does U357C mean on a 2024–2025 Honda Prologue?

The supplied verified evidence does not establish a standalone definition for U357C. It identifies U357C as one DTC in the required code set referenced by Honda bulletin A25-043.

Does Honda bulletin A25-043 apply if U357C is the only code present?

No, based on the supplied bulletin excerpt. The bulletin requires all listed DTCs to be set as current or history; if all are not set, the bulletin does not apply.

Which vehicles are covered by the supplied evidence?

The supplied applicability data identifies U.S. 2024–2025 Honda Prologue vehicles.

Is it safe to drive or charge with U357C?

Not yet established by verified evidence.

20. Sources & verification

Accepted ResearchVerified
Honda U357C: If all of these DTCs are NOT SET as current or history,… | EV Diagnostics