EV Diagnostics
Verified EV diagnostic knowledge page

Audi B127E4B

Replacing the control module for driver assistance systems (J1121) for the above mentioned DTCs is not effective. Scenario 1: When

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact an authorized Audi service provider for diagnosis. The supplied official communication indicates that replacing J1121 is not effective for this DTC group.
Confidence95%

Quick answer

For Audi A7, A8, and e-tron vehicles (model years 2019–2022, US), DTC B127E4B is listed in an official Audi/NHTSA manufacturer communication for the right overhead-view camera. The communication specifically states that replacing the driver-assistance systems control module (J1121) is not effective for the listed DTCs.

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

Video guides

Watch Videos

Relevant videos play here without leaving this diagnostic page.

No sufficiently relevant embeddable video has been accepted for this diagnostic yet.

Videos are supporting material and never override OEM or regulator evidence.

1. What does B127E4B mean?

For Audi A7, A8, and e-tron vehicles (model years 2019–2022, US), DTC B127E4B is listed in an official Audi/NHTSA manufacturer communication for the right overhead-view camera. The communication specifically states that replacing the driver-assistance systems control module (J1121) is not effective for the listed DTCs.

2. Technical explanation

Verified evidence identifies B127E4B as a DTC associated with the right overhead-view camera. The supplied official communication also groups it with other overhead-view camera DTCs and states that replacement of J1121 is not an effective remedy for these DTCs. The supplied excerpt does not establish the complete diagnostic procedure, underlying fault mechanism, or final repair for B127E4B.

3. What system is affected?

Right overhead-view camera / driver-assistance system. The exact system name is not otherwise established by the supplied verified evidence.

4. How serious is this code?

Not yet established by verified evidence.

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

  • Do not assume that replacement of the driver-assistance systems control module J1121 will resolve B127E4B; the official communication says this is not effective for the listed DTCs.
  • Have the vehicle assessed using applicable Audi service information and diagnostic equipment.

10. Step-by-step troubleshooting

  1. Confirm the stored DTC is B127E4B.
  2. Refer to the applicable Audi manufacturer communication and current service information. The supplied evidence does not provide further diagnostic steps.

11. When to contact service

Contact an authorized Audi service provider for diagnosis. The supplied official communication indicates that replacing J1121 is not effective for this DTC group.

12. What the service center may check

  • Verify B127E4B is present in diagnostic records.
  • Review the applicable Audi/NHTSA manufacturer communication, reference MC-10181431-0001 / A9120172055188_3.
  • Further service checks are not yet established by the supplied verified evidence.

13. Possible repair or resolution

  • Do not treat replacement of the driver-assistance systems control module (J1121) as an effective resolution for B127E4B based on the official communication.
  • The final repair resolution is not yet established by the supplied verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Official manufacturer communication: NHTSA Manufacturer Communication PDF 10181431, document A9120172055188_3, published October 15, 2020. It lists B127E4B for the right overhead-view camera and states that replacing J1121 is not effective for the listed DTCs.
  • Source: https://static.nhtsa.gov/odi/tsbs/2020/MC-10181431-0001.pdf

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Applicable verified vehicle coverage: US-market Audi A7, A8, and e-tron model years 2019–2022. Source: NHTSA manufacturer communication MC-10181431-0001 (Audi document A9120172055188_3), published October 15, 2020: https://static.nhtsa.gov/odi/tsbs/2020/MC-10181431-0001.pdf

19. Frequently asked questions

What does Audi DTC B127E4B relate to?

The supplied official communication lists B127E4B for the right overhead-view camera.

Will replacing J1121 fix B127E4B?

The official communication states that replacing the control module for driver assistance systems (J1121) is not effective for the listed DTCs, including B127E4B.

Which vehicles are covered by the supplied evidence?

US-market 2019–2022 Audi A7, A8, and e-tron vehicles.

Is there a verified final repair procedure?

Not yet established by the supplied verified evidence.

20. Sources & verification

Verified
Audi B127E4B: Replacing the control module for driver assistance… | EV Diagnostics