Audi B16D7F4
Right tail lamp 2 Turn signal light defective
Quick answer
For applicable 2019–2020 US Audi e-tron vehicles, DTC B16D7F4 means “Right tail lamp 2 Turn signal light defective.” Audi documentation states that the turn signals remain functional and identifies a timing issue in tail-lamp software as the technical background.
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 B16D7F4 mean?
For applicable 2019–2020 US Audi e-tron vehicles, DTC B16D7F4 means “Right tail lamp 2 Turn signal light defective.” Audi documentation states that the turn signals remain functional and identifies a timing issue in tail-lamp software as the technical background.
2. Technical explanation
Audi identifies B16D7F4 as a fault stored in the comfort control module J393 (address word 0046). The code refers specifically to right tail lamp 2 and its turn-signal light. In the cited Audi communications, the reported condition is associated with a tail-lamp software timing issue.
3. What system is affected?
Right tail lamp 2 turn-signal function; the DTC is stored in the comfort control module J393 (address word 0046).
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- The turn signals remain functional, according to the cited Audi manufacturer communications.
- DTC B16D7F4 may be stored in comfort control module J393 (address word 0046).
6. Possible causes
- Audi identifies a timing issue in the tail-lamp software as the technical background for this condition on the covered vehicles.
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 with an Audi service provider if B16D7F4 is present.
- Do not assume that a functional turn signal means the stored DTC has been resolved.
10. Step-by-step troubleshooting
- Confirm whether the vehicle is a 2019–2020 Audi e-tron in the US.
- Check for DTC B16D7F4 in comfort control module J393, address word 0046.
- Have Audi determine whether the applicable tail-lamp software update applies.
11. When to contact service
Contact an Audi service provider for diagnosis and applicability confirmation. The supplied evidence does not establish whether service is required in every case.
12. What the service center may check
- Verify B16D7F4 in comfort control module J393 (address word 0046).
- Evaluate the condition in accordance with the applicable Audi manufacturer communication.
- Confirm the tail-lamp software level and whether updated software is applicable.
13. Possible repair or resolution
- Audi states that new software in tail lamps MX3, MX4, and MX13 addressed the condition.
- Not yet established by verified evidence whether any other repair is required.
14. Affected vehicles
- Audi e-tron · 2019–2020 · US
15. Related TSBs / service bulletins
- Audi manufacturer communication A9421492062241_2, published November 19, 2021; available through NHTSA as MC-10203693-0001: https://static.nhtsa.gov/odi/tsbs/2021/MC-10203693-0001.pdf
- Audi manufacturer communication A9421352062241_1, published February 23, 2021; available through NHTSA as MC-10187587-0001: https://static.nhtsa.gov/odi/tsbs/2021/MC-10187587-0001.pdf
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified applicability: Audi e-tron, model years 2019–2020, US. The supplied official Audi communications describe a tail-lamp software timing issue and state that updated software in tail lamps MX3, MX4, and MX13 addressed the condition.
19. Frequently asked questions
What does B16D7F4 mean?
It means “Right tail lamp 2 Turn signal light defective.”
Are the turn signals functional with this code?
The cited Audi communications state that the turn signals remain functional.
What does Audi identify as the technical background?
Audi identifies a timing issue in the tail-lamp software.
Which vehicles are verified as applicable?
The supplied evidence establishes applicability for US 2019–2020 Audi e-tron vehicles.
Is this a recall?
Not yet established by verified evidence.