Audi B12CB15
up light bulb Open circuit/ short circuit to B+). DTC B12CC15 (Right back-up light bulb Open circuit/short circuit to B+). Technical Background The internal circuit board for the
Quick answer
For a 2020 Audi Q5 in the US, DTC B12CB15 is documented as a left back-up light bulb circuit fault: “Open circuit/short circuit to B+.” Audi’s bulletin describes a possible reverse-lamp internal circuit-board separation in the rear-bumper lamp.
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 B12CB15 mean?
For a 2020 Audi Q5 in the US, DTC B12CB15 is documented as a left back-up light bulb circuit fault: “Open circuit/short circuit to B+.” Audi’s bulletin describes a possible reverse-lamp internal circuit-board separation in the rear-bumper lamp.
2. Technical explanation
Audi documents B12CB15 as: Left back-up light bulb — open circuit/short circuit to B+. The DTC may be stored in the comfort system control module J393 (address word 0046). The verified bulletin states that the internal circuit board for the reverse lamp, located in the lamps on the rear bumper, may separate from the tail-lamp housing. When this occurs, the metal contact loses connection.
3. What system is affected?
Left reverse/back-up lamp circuit; comfort system control module J393 (address 0046).
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- A tail-lamp warning may be displayed in the instrument cluster.
- DTC B12CB15 may be stored in comfort system control module J393.
6. Possible causes
- The internal circuit board for the reverse lamp in the rear-bumper lamp may become separated from the tail-lamp housing.
- When separation occurs, the metal contact loses connection.
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
- Arrange diagnosis by an Audi-qualified service provider.
- Report any instrument-cluster tail-lamp warning and the stored code B12CB15.
- Do not attempt high-voltage repairs; no high-voltage repair procedure is established by the supplied evidence.
10. Step-by-step troubleshooting
- A service provider can confirm whether B12CB15 is stored in comfort system control module J393 (address 0046).
- A service provider can assess the reverse lamp in the rear bumper for the bulletin-described circuit-board separation and loss of metal-contact connection.
11. When to contact service
Contact an Audi service provider for diagnosis, particularly if a tail-lamp warning is displayed or B12CB15 is present.
12. What the service center may check
- Check comfort system control module J393 (address word 0046) for B12CB15.
- Inspect the rear-bumper reverse lamp for separation of its internal circuit board from the tail-lamp housing.
- Assess whether the metal contact has lost connection as described in the bulletin.
13. Possible repair or resolution
- Not yet established by verified evidence.
14. Affected vehicles
- Audi Q5 · 2020 · US
15. Related TSBs / service bulletins
- NHTSA Manufacturer Communication PDF 10201520: A9421452063766_1, published September 2, 2021. It applies to 2018–2020 Audi Q5 and SQ5 and 2020 Q5 PHEV vehicles, with all VIN ranges listed. The supplied applicability record specifically identifies the 2020 Audi Q5 in the US.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Official source: NHTSA Manufacturer Communication PDF 10201520: A9421452063766_1 — https://static.nhtsa.gov/odi/tsbs/2021/MC-10201520-0001.pdf
19. Frequently asked questions
What does Audi code B12CB15 mean?
Audi documents B12CB15 as a left back-up light bulb open-circuit/short-circuit-to-B+ fault.
What warning may occur with B12CB15?
The verified bulletin states that a tail-lamp warning may be displayed in the instrument cluster.
What component is described in the bulletin?
The bulletin describes the reverse lamp located in the rear bumper, where an internal circuit board may separate from the tail-lamp housing and cause loss of metal-contact connection.
Is this confirmed as safe or unsafe to drive?
Not yet established by verified evidence.