Audi U015100
Airbag control unit no communication
Quick answer
For certain 2019–2020 Audi e-tron vehicles in the US, DTC U015100 can be stored in the ABS control module with an ESC warning light due to a timing condition as the vehicle enters sleep mode. Audi states that waking the bus—for example, by opening a door or connecting the charger—can mistakenly trigger the code. New software was being prepared at the time of the bulletin.
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 U015100 mean?
For certain 2019–2020 Audi e-tron vehicles in the US, DTC U015100 can be stored in the ABS control module with an ESC warning light due to a timing condition as the vehicle enters sleep mode. Audi states that waking the bus—for example, by opening a door or connecting the charger—can mistakenly trigger the code. New software was being prepared at the time of the bulletin.
2. Technical explanation
U015100 means “Airbag control unit no communication.” In the verified Audi/NHTSA bulletin, this code may be stored in the ABS control module, J104 (address word 0003), rather than establishing a confirmed failed airbag control unit. The bulletin describes a small time window while the vehicle enters sleep mode: waking the vehicle communication bus can mistakenly cause U015100 and illuminate the ESC warning light.
3. What system is affected?
ABS control module J104 (address word 0003), vehicle communication bus, and ESC warning indication. The code description refers to communication with the airbag control unit.
4. How serious is this code?
Not yet established by verified evidence. The verified bulletin identifies an ESC warning light and a potentially mistaken stored DTC during vehicle sleep-mode entry, but does not provide a driving-risk classification.
5. Symptoms you may notice
- ESC warning light on.
- U015100 may be stored in the ABS control module J104 (address word 0003).
6. Possible causes
- During vehicle sleep-mode entry, the communication bus may be awakened within a small timing window.
- Examples of bus wake-up events identified by Audi include opening a door or connecting the charger.
- Audi states that this timing condition can mistakenly cause U015100 in the ABS control module.
7. Can I still drive the vehicle?
Not yet established by verified evidence.
8. Can I charge the vehicle?
The verified bulletin identifies connecting the charger as an example of a bus wake-up event that can mistakenly trigger the stored DTC during sleep-mode entry. Whether the vehicle can be charged with this code present is not yet established by verified evidence.
9. What you can safely do
- If an ESC warning light is displayed, arrange diagnosis by an authorized Audi service provider.
- Record when the warning occurred, including whether a door was opened or the charger was connected while the vehicle was entering sleep mode.
- Do not attempt high-voltage or airbag-system repairs.
10. Step-by-step troubleshooting
- Have a service provider check whether U015100 is stored in ABS control module J104 (address word 0003).
- Have the provider evaluate the condition against Audi communication A4519132055702_1 and applicable software information.
11. When to contact service
Contact an authorized Audi service provider for diagnosis, particularly if the ESC warning light is illuminated or the code returns.
12. What the service center may check
- Confirm whether U015100 is stored in ABS control module J104 (address word 0003).
- Check for the ESC warning light condition described in the Audi bulletin.
- Assess whether the event occurred as the vehicle entered sleep mode and the bus was awakened, such as by opening a door or connecting the charger.
- Check for applicable software updates described by Audi.
13. Possible repair or resolution
- Audi's bulletin states that new software was being prepared. The verified evidence does not establish the final software version, repair procedure, or repair outcome.
14. Affected vehicles
- Audi e-tron · 2019–2020 · US
15. Related TSBs / service bulletins
- NHTSA Manufacturer Communication PDF 10163426: A4519132055702_1, published July 26, 2019. Applicable verified population: 2019–2020 Audi e-tron, US. The bulletin describes mistakenly stored U015100 in the ABS control module during a sleep-mode/bus-wake timing condition and states that new software was being prepared.
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified official source: NHTSA-hosted Audi manufacturer communication 10163426, A4519132055702_1: https://static.nhtsa.gov/odi/tsbs/2019/MC-10163426-0001.pdf
19. Frequently asked questions
What does U015100 mean?
It means “Airbag control unit no communication.”
Which vehicles are covered by the verified bulletin?
The verified applicability is Audi e-tron model-year 2019–2020 vehicles in the US.
Why can this code occur according to Audi?
Audi states that while the vehicle is entering sleep mode, waking the communication bus in a small timing window—such as by opening a door or connecting the charger—can mistakenly cause the DTC in the ABS control module and turn on the ESC warning light.
Does this bulletin prove that the airbag control unit has failed?
No. The verified bulletin describes a condition in which U015100 can be mistakenly stored in the ABS control module. It does not establish a failed airbag control unit.
Is there a confirmed fix?
The bulletin states that new software was being prepared. A final software version or repair procedure is not established by the supplied verified evidence.