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Audi C12EBF1

laser for adaptive cruise control, malfunction

DriveNot yet established by verified evidence. Audi communications state that, after the applicable update, the vehicle can be released if Adaptive Cruise Assist can be reactivated.
ChargeNot yet established by verified evidence.
ServiceContact an Audi dealer or qualified Audi service provider, especially if Adaptive Cruise Assist remains unavailable or cannot be reactivated.
Confidence95%

Quick answer

C12EBF1 indicates a malfunction reported for the laser used by Adaptive Cruise Assist. For specified U.S. Audi applications, Audi service communications identify a laser-scanner control-module software issue and prescribe a software update.

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 C12EBF1 mean?

C12EBF1 indicates a malfunction reported for the laser used by Adaptive Cruise Assist. For specified U.S. Audi applications, Audi service communications identify a laser-scanner control-module software issue and prescribe a software update.

2. Technical explanation

Audi identifies C12EBF1 as “laser for adaptive cruise control, malfunction.” The code is stored in the laser-scanner control module J1122 (address word 00CD). In the applicable Audi service communications, the documented technical background is a software bug or a need to update software to correct an Adaptive Cruise Assist activation issue. A stored C12EBF1 can remain after certain updates with no further effect on functionality, according to the relevant Audi communications.

3. What system is affected?

Adaptive Cruise Assist / adaptive driving assistance; laser-scanner control module J1122 (address word 00CD).

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • Adaptive driving assistance or Adaptive Cruise Assist is unavailable or cannot be activated.
  • After a short time, the system may become available again without an ignition cycle.
  • The documented code may be stored in J1122, the laser-scanner control module.

6. Possible causes

  • For the covered Audi service cases, Audi identifies a software bug in the laser-scanner control module.
  • Audi also states that software requires updating to correct the Adaptive Cruise Assist activation issue.
  • Other causes are not yet established by verified evidence.

7. Can I still drive the vehicle?

Not yet established by verified evidence. Audi communications state that, after the applicable update, the vehicle can be released if Adaptive Cruise Assist can be reactivated.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Do not rely on Adaptive Cruise Assist while it is unavailable or cannot be activated.
  • Arrange diagnosis by an Audi service provider to confirm whether the applicable software update applies.
  • Do not perform laser-scanner or high-voltage-system repair work yourself.

10. Step-by-step troubleshooting

  1. Have the vehicle scanned for C12EBF1 in laser-scanner control module J1122, address word 00CD.
  2. Have an Audi service provider check the applicable Audi software-update guidance for the vehicle.
  3. After the applicable update, Audi guidance notes that a bus-sleep period may be required before clearing DTCs.
  4. A remaining C12EBF1 with specified symptom codes after an update may have no effect on system functionality; this determination should be made using the applicable Audi service information.

11. When to contact service

Contact an Audi dealer or qualified Audi service provider, especially if Adaptive Cruise Assist remains unavailable or cannot be reactivated.

12. What the service center may check

  • Confirm C12EBF1 in J1122, the laser-scanner control module at address word 00CD.
  • Confirm whether the vehicle matches the covered model year, model, and U.S. applicability in Audi communications.
  • Check installed laser-scanner control-module software and apply the applicable Audi software update.
  • Verify whether Adaptive Cruise Assist can be reactivated after the update.
  • Follow applicable Audi instructions regarding bus sleep and DTC clearing.

13. Possible repair or resolution

  • For documented applicable cases, update the laser-scanner control-module software using Audi service procedures.
  • Audi communications for certain software versions state that a stored C12EBF1 with symptom code 11546627 may be ignored after updating if it no longer affects functionality and Adaptive Cruise Assist can be reactivated.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Audi/NHTSA manufacturer communication A9121602061817_2, published January 8, 2021: software update for adaptive driving assistance activation issue associated with C12EBF1.
  • Audi/NHTSA manufacturer communication A9120562061817_1, published December 18, 2020: replaces PSS TSB 2055338 and calls for a software update.
  • Audi/NHTSA manufacturer communication A9120542053776_7, published December 18, 2020: after update to SW0304, C12EBF1 with symptom code 11546627 may remain stored without affecting functionality.
  • Audi/NHTSA manufacturer communication A9120422055338_4, published December 7, 2020: identifies a software bug in J1122.
  • Audi/NHTSA manufacturer communication A9120472055338_3, published March 6, 2020: earlier communication concerning the same software bug.
  • Audi/NHTSA manufacturer communication A9120292053776_4, published January 15, 2020: notes post-update handling for C12EBF1 with symptom code 11546627.
  • Audi/NHTSA manufacturer communication A9119052055338_2, published October 29, 2019: earlier communication concerning the same software bug.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified NHTSA-hosted Audi manufacturer communications: https://static.nhtsa.gov/odi/tsbs/2021/MC-10185683-0001.pdf ; https://static.nhtsa.gov/odi/tsbs/2020/MC-10185261-0001.pdf ; https://static.nhtsa.gov/odi/tsbs/2020/MC-10185263-0001.pdf ; https://static.nhtsa.gov/odi/tsbs/2020/MC-10185282-0001.pdf

19. Frequently asked questions

What does C12EBF1 mean?

Audi defines it as “laser for adaptive cruise control, malfunction.”

What is the documented cause?

For the covered Audi service cases, Audi identifies a software bug in the laser-scanner control module or states that software needs updating.

Can the issue clear without cycling the ignition?

Audi documents cases where Adaptive Cruise Assist became available again after a short time without an ignition cycle.

Does a stored code always mean the system still has a functional problem after an update?

No. Audi states that after specified updates, C12EBF1 with symptom code 11546627 may remain stored but have no further influence on functionality.

20. Sources & verification

Verified
Audi C12EBF1: laser for adaptive cruise control, malfunction | EV Diagnostics