Audi C1399F0
in process then takes place when the brakes are applied while driving. This is not shown actively to the customer in the instrument cluster or the MMI. This mode and the DTC are de
Quick answer
Audi DTC C1399F0 indicates that brake application mode is active during a brake-pad/disc break-in process. In the verified Audi material, the DTC is logged in the ABS control module and is automatically deactivated when the required energy amount is reached.
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 C1399F0 mean?
Audi DTC C1399F0 indicates that brake application mode is active during a brake-pad/disc break-in process. In the verified Audi material, the DTC is logged in the ABS control module and is automatically deactivated when the required energy amount is reached.
2. Technical explanation
Audi’s verified manufacturer communications describe C1399F0 as “Brake application mode active.” This mode is used for breaking in brake pads on the discs. While active, recuperation is deactivated and braking is performed manually. The break-in process occurs when the brakes are applied while driving. The mode and DTC automatically deactivate once the required amount of energy is reached.
3. What system is affected?
ABS control module J104, address word 0003; brake application mode; brake pad/disc break-in process.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- C1399F0 may be stored in ABS control module J104.
- Recuperation is deactivated while brake application mode is active.
- The brake-pad/disc break-in process takes place when brakes are applied during driving.
- Audi states this mode is not actively shown to the customer in the instrument cluster or MMI.
6. Possible causes
- Verified context: brake application mode is active for brake-pad/disc break-in.
- Not yet established by verified evidence whether C1399F0, in this documented context, indicates a component fault.
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
- Do not attempt high-voltage or brake-system repairs based on this page.
- Have a qualified Audi service provider evaluate the vehicle if the code is present outside a documented brake-pad/disc break-in procedure or if there are brake concerns.
10. Step-by-step troubleshooting
- Confirm whether Audi brake-pad/disc break-in was initiated using the Test Plan “003 Brake-In Service Pads.”
- Read fault memory in ABS control module J104, address word 0003, with suitable diagnostic equipment.
- Verify whether the required break-in energy amount has been reached; Audi states the mode and DTC deactivate automatically when it is reached.
11. When to contact service
Contact an authorized Audi service provider for diagnosis if C1399F0 does not clear after the documented break-in process or if there are any braking concerns.
12. What the service center may check
- Check ABS control module J104 (address word 0003) for DTC C1399F0.
- Determine whether brake application mode was initiated for brake-pad/disc break-in.
- Confirm whether the documented break-in process has completed and the required energy amount has been reached.
13. Possible repair or resolution
- Audi’s verified communications state that C1399F0 and brake application mode automatically deactivate when the required amount of energy is reached.
- No component repair procedure is established by the supplied verified evidence.
14. Affected vehicles
- Audi RS e-tron GT · 2022–2023 · US
- Audi e-tron · 2022 · US
- Audi e-tron GT · 2022–2023 · US
15. Related TSBs / service bulletins
- NHTSA Manufacturer Communication 10212111, published May 20, 2022: Documents C1399F0 during Audi brake-pad/disc break-in, with recuperation deactivated and manual braking used. https://static.nhtsa.gov/odi/tsbs/2022/MC-10212111-0001.pdf
- NHTSA Manufacturer Communication 10198161, published June 16, 2021: Documents C1399F0 as “Brake application mode active” in ABS control module J104 during brake-pad/disc break-in. https://static.nhtsa.gov/odi/tsbs/2021/MC-10198161-0001.pdf
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified NHTSA-hosted Audi manufacturer communications describe C1399F0 in connection with brake application mode for brake-pad/disc break-in. Applicable vehicles in the supplied evidence are US-market 2022 Audi e-tron and 2022–2023 Audi e-tron GT and RS e-tron GT.
19. Frequently asked questions
What does Audi C1399F0 mean?
Verified Audi communication identifies C1399F0 as “Brake application mode active.” It is logged during a brake-pad/disc break-in process.
Where is C1399F0 stored?
The verified material states that it is stored in ABS control module J104, address word 0003.
Why is recuperation unavailable when C1399F0 is active?
Audi states that recuperation is deactivated while the brake application mode is active and braking is performed manually.
Will the driver see brake application mode in the instrument cluster or MMI?
Audi states that this mode is not actively shown to the customer in the instrument cluster or MMI.
Does C1399F0 clear by itself?
Audi states that brake application mode and the DTC deactivate automatically when the required amount of energy is reached.