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Audi B127D04

Replacing the control module for driver assistance systems (J1121

DriveUnknown. The supplied verified evidence does not establish whether the vehicle is safe to drive with B127D04.
ChargeUnknown. The supplied verified evidence does not establish whether the vehicle is safe to charge with B127D04.
ServiceService need is not explicitly established by the supplied evidence. However, Audi-qualified diagnosis is appropriate because the verified communication concerns a driver-assistance camera system and control-module context.
Confidence95%

Quick answer

B127D04 is identified in verified Audi service information as a diagnostic trouble code associated with the rear overhead-view camera. The supplied evidence also references replacement of the control module for driver assistance systems (J1121), but does not establish a complete fault description or a specific repair for this code alone.

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 B127D04 mean?

B127D04 is identified in verified Audi service information as a diagnostic trouble code associated with the rear overhead-view camera. The supplied evidence also references replacement of the control module for driver assistance systems (J1121), but does not establish a complete fault description or a specific repair for this code alone.

2. Technical explanation

Verified NHTSA-hosted Audi manufacturer communication 10181431 lists B127D04 in a group for the rear overhead-view camera, alongside C12AF02 and B127D4B. The communication’s supplied excerpt also includes the phrase “Replacing the control module for driver assistance systems (J1121,” but the excerpt is truncated. Therefore, the exact relationship between B127D04 and module replacement is not fully established by the verified evidence provided.

3. What system is affected?

Rear overhead-view camera / driver-assistance system context. The specific affected component and fault mechanism are not yet established by verified evidence.

4. How serious is this code?

Unknown. The supplied verified evidence does not assign a severity level.

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?

Unknown. The supplied verified evidence does not establish whether the vehicle is safe to drive with B127D04.

8. Can I charge the vehicle?

Unknown. The supplied verified evidence does not establish whether the vehicle is safe to charge with B127D04.

9. What you can safely do

  • Arrange diagnosis by an Audi-qualified service provider.
  • Record any driver-assistance or camera warnings and preserve the diagnostic scan results.
  • Do not assume that replacement of any control module is required based on this code alone.

10. Step-by-step troubleshooting

  1. Use Audi diagnostic procedures and the applicable manufacturer communication to evaluate B127D04 in the rear overhead-view camera context.
  2. Not yet established by verified evidence: specific inspection steps, test values, wiring checks, software actions, coding steps, or component replacement criteria.

11. When to contact service

Service need is not explicitly established by the supplied evidence. However, Audi-qualified diagnosis is appropriate because the verified communication concerns a driver-assistance camera system and control-module context.

12. What the service center may check

  • Confirm the stored DTCs and associated diagnostic information.
  • Review the applicable Audi manufacturer communication referenced below.
  • Not yet established by verified evidence: the exact required diagnostic checks or repair decision criteria.

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied communication excerpt references replacement of control module J1121, but does not provide enough verified context to conclude that module replacement resolves B127D04 in every case.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA Manufacturer Communication PDF 10181431, Audi reference A9120172055188_3, published October 15, 2020. Verified excerpt lists B127D04 under “Rear overhead view camera” and references “Replacing the control module for driver assistance systems (J1121.”
  • Applicability in supplied data: 2019–2022 Audi A7, A8, and e-tron, US market.

16. Recall information

  • No recall information was supplied or established by verified evidence.

17. Official manufacturer information

Official source: NHTSA-hosted Audi manufacturer communication 10181431 (A9120172055188_3): https://static.nhtsa.gov/odi/tsbs/2020/MC-10181431-0001.pdf

19. Frequently asked questions

What does Audi code B127D04 refer to?

The verified Audi communication lists B127D04 in the rear overhead-view camera group. A complete fault description is not established by the supplied evidence.

Which vehicles are covered by the supplied applicability data?

The supplied data identifies US-market 2019–2022 Audi A7, A8, and e-tron vehicles.

Does B127D04 prove that J1121 must be replaced?

No. The verified excerpt references replacement of the control module for driver assistance systems (J1121), but it does not establish that replacement is required for every B127D04 occurrence.

Can I drive or charge the vehicle with B127D04?

Not yet established by verified evidence.

20. Sources & verification

Verified
Audi B127D04: Replacing the control module for driver assistance… | EV Diagnostics