Audi B122D29
implausible signal). Technical Background The software needs to be updated. Production Solution New software in the door electronics control module, J386 – J389 (0042 – drivers, 00
Quick answer
For certain 2019–2020 US Audi e-tron vehicles, DTC B122D29 identifies an implausible signal from the central-locking locking unit. Audi manufacturer communications state that the software needs to be updated in the door electronics control module(s).
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 B122D29 mean?
For certain 2019–2020 US Audi e-tron vehicles, DTC B122D29 identifies an implausible signal from the central-locking locking unit. Audi manufacturer communications state that the software needs to be updated in the door electronics control module(s).
2. Technical explanation
Audi identifies B122D29 as “locking unit for central locking - implausible signal.” The DTC may be stored in one or more door control modules J386–J389: driver door (0042), passenger door (0052), rear driver-side door (00BB), and rear passenger-side door (00BC). Audi’s documented technical background is that the software needs to be updated. A production solution was new software in the door electronics control modules.
3. What system is affected?
Door electronics and central-locking system; specifically door control modules J386–J389.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- An affected door may temporarily not be electronically unlocked from the inside.
- A “Malfunction! Please go to workshop” message may be shown in the instrument cluster.
- Mechanical opening of the affected door is possible, according to the Audi manufacturer communications.
6. Possible causes
- Audi’s verified technical background states that door-electronics-control-module software needs to be updated.
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
- If electronic unlocking from inside a door is unavailable, use the mechanical opening method described in the vehicle’s owner documentation.
- Arrange Audi service for diagnostic confirmation and applicable door-control-module software updating.
10. Step-by-step troubleshooting
- Have a qualified Audi service facility check for B122D29 in door control modules J386–J389.
- The cited communications also identify B14FF29 in door modules and U122800 in the ABS control module as potentially stored with this condition.
- Do not attempt high-voltage or vehicle-module repair procedures yourself.
11. When to contact service
Contact an authorized Audi service facility. The official Audi manufacturer communications instruct service personnel to perform an SVM software update procedure when applicable.
12. What the service center may check
- Check door control modules J386–J389 at addresses 0042, 0052, 00BB, and 00BC for B122D29.
- Where applicable, check for B14FF29 in one or more door modules.
- Where applicable, check ABS control module J104 at address 0003 for U122800.
- Confirm and perform the applicable Audi SVM software update according to current Audi service information.
13. Possible repair or resolution
- Audi documented new software for door electronics control modules J386–J389 as the production solution.
- Audi’s service direction is a software update for the affected door electronics control module(s).
14. Affected vehicles
- Audi e-tron · 2019–2020 · US
15. Related TSBs / service bulletins
- Audi manufacturer communication A5719582055933_1, published August 30, 2019; NHTSA communication MC-10164483-0001: https://static.nhtsa.gov/odi/tsbs/2019/MC-10164483-0001.pdf
- Audi manufacturer communication A5719612055933_2, published November 25, 2019; NHTSA communication MC-10168644-0001: https://static.nhtsa.gov/odi/tsbs/2019/MC-10168644-0001.pdf
- Audi manufacturer communication A5720692055933_3, published June 17, 2020; NHTSA communication MC-10176752-0001: https://static.nhtsa.gov/odi/tsbs/2020/MC-10176752-0001.pdf
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified applicability: Audi e-tron, model years 2019–2020, United States. The cited records are NHTSA-hosted Audi manufacturer communications, not verified recall records.
19. Frequently asked questions
What does Audi code B122D29 mean?
Audi identifies B122D29 as “locking unit for central locking - implausible signal.”
What may happen when B122D29 is present?
Audi states that an affected door may temporarily not electronically unlock from inside. Mechanical opening is possible.
What is Audi’s documented remedy?
Audi states that software in the door electronics control module needs to be updated; new door-module software is documented as the production solution.
Which vehicles are verified as applicable?
The supplied verified applicability identifies US-market 2019–2020 Audi e-tron vehicles.