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Audi Rear cross-traffic assist: fault. Please contact workshop.

Rear cross-traffic assist: fault. Please contact workshop.

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceYes. The alert explicitly states, “Please contact workshop.”
Confidence90%

Quick answer

This Audi alert indicates a fault affecting rear cross-traffic assist. The verified Audi service evidence directs contacting a workshop.

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 Rear cross-traffic assist: fault. Please contact workshop. mean?

This Audi alert indicates a fault affecting rear cross-traffic assist. The verified Audi service evidence directs contacting a workshop.

2. Technical explanation

Verified Audi technical-service evidence lists this instrument-cluster message when intersection/lane-change assist functions are inoperative. In one documented scenario, DTC C12BFF0, “Radar sensor automatic calibration not possible,” may be stored in a lane-change-assist control module (J769/J770) or a radar sensor control module for object detection (J1088/J1089). The supplied evidence does not establish that this DTC is present in every vehicle displaying the alert.

3. What system is affected?

Rear cross-traffic assist; verified service evidence also associates the message with the intersection/lane-change-assist system.

4. How serious is this code?

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

5. Symptoms you may notice

  • Instrument-cluster message: “Rear cross-traffic assist: fault. Please contact workshop.”
  • Rear cross-traffic assist fault.
  • Verified service evidence describes intersection/lane-change assist as inoperative in documented cases.

6. Possible causes

  • A documented service scenario may involve DTC C12BFF0: “Radar sensor automatic calibration not possible.”
  • The supplied evidence does not establish the underlying cause of the calibration fault.

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

  • Follow the displayed instruction to contact a workshop.
  • Do not rely on rear cross-traffic assist or the associated intersection/lane-change-assist functions while the fault message is displayed.

10. Step-by-step troubleshooting

  1. Have a qualified workshop check for stored fault information in lane-change-assist control modules J769/J770 (address words 003C/00CF) and radar sensor control modules for object detection J1088/J1089 (address words 00DB/00DC).
  2. Check whether DTC C12BFF0, “Radar sensor automatic calibration not possible,” is stored. This is a documented finding, not a confirmed diagnosis for every occurrence.

11. When to contact service

Yes. The alert explicitly states, “Please contact workshop.”

12. What the service center may check

  • Confirm the customer-reported rear cross-traffic-assist fault message.
  • Assess operation of intersection/lane-change assist functions.
  • Read diagnostic information from J769/J770 and J1088/J1089.
  • Check for DTC C12BFF0, “Radar sensor automatic calibration not possible.”

13. Possible repair or resolution

  • Not yet established by verified evidence. The supplied excerpts identify a documented fault-message scenario and diagnostic finding but do not provide the repair procedure or final resolution.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Audi technical service bulletin/Manufacturer Communication 10233770, A9623842063336_3, published March 8, 2023. It documents the message “Rear cross-traffic assist: fault. Please contact workshop.” in a condition where intersection/lane-change assist is inoperative.
  • Audi technical service bulletin/Manufacturer Communication 10197970, A9621702063336_1, published June 10, 2021. It documents this message and reports that DTC C12BFF0 may be stored in specified lane-change-assist or radar sensor control modules.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official NHTSA-hosted Audi manufacturer communications: 10233770 (A9623842063336_3) and 10197970 (A9621702063336_1).

19. Frequently asked questions

What does this Audi message mean?

It indicates a rear cross-traffic-assist fault and instructs the driver to contact a workshop. Verified Audi service evidence links the message to documented cases of inoperative intersection/lane-change assist.

Can I keep driving?

Not yet established by verified evidence. The supplied evidence does establish that assistance functions may be inoperative; do not rely on them.

Is a diagnostic trouble code associated with this message?

In a documented Audi service scenario, C12BFF0, “Radar sensor automatic calibration not possible,” may be stored in J769/J770 or J1088/J1089. Its presence is not established for every vehicle with this alert.

Which vehicles are covered by the supplied applicability evidence?

US-market Audi A7 (2019–2024), A8 (2019–2024), Q4 e-tron (2019–2024), RS e-tron GT (2019–2024), e-tron (2019–2024), and e-tron GT (2019–2024). Some supplied entries also list narrower overlapping ranges for the A7, A8, and e-tron.

20. Sources & verification

Verified
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