2022 Audi e-tron DTC C1399F0 for Low Brake Recuperation

Symptoms

Owners of 2022 Audi e-tron vehicles may notice "Recuperation too low" when braking. This condition is particularly common in new vehicles or after the brake discs or brake pads have been replaced.

Fault Codes / DTCs

Technicians investigating this issue may find the following Diagnostic Trouble Code stored in the ABS control module, J104 (address word 0003):

Code	Description	Module
C1399F0	Brake application mode active	ABS control module J104

Technical Background and Diagnosis

Audi vehicles, including the 2022 Audi e-tron, utilize a specific "brake application mode" for breaking in new brake pads and discs. During this period, the vehicle temporarily deactivates its recuperation function, and braking is performed manually.

While this break-in process is active, the system logs the "2022 Audi e-tron DTC C1399F0" (Brake application mode active) in the ABS control module, J104. This is a normal operational state and not indicative of a fault.

This mode and the associated DTC C1399F0 will automatically deactivate once the required amount of energy has been reached, signaling the completion of the break-in process. The vehicle's instrument cluster or MMI does not actively display any notification to the customer about this break-in mode.

Repair Procedure Summary

If a 2022 Audi e-tron is exhibiting symptoms of low recuperation or has the "2022 Audi e-tron DTC C1399F0" stored, technicians should follow these steps:

1. Access the ODIS diagnostic system (via GFF or Guided Functions).
2. Select the function labeled "003 Break-in service brakes."
3. Follow any specific instructions provided by the diagnostic tester, especially if brake discs or pads have been recently replaced or if the DTC C1399F0 is present.
4. After completing the procedure, reevaluate the vehicle's braking system and release it.

Warranty Information

Audi provides warranty coverage for this issue under specific conditions:

• Up to 48 months or 50,000 miles.
• For Certified Pre-Owned (CPO) vehicles, coverage falls under G10, requiring owner verification.
• If the vehicle is outside of these warranty parameters, this Technical Service Bulletin serves as informational guidance only.

The service number for this procedure is 4530, with a damage code of 0040. Diagnostic time is GFF 0150 0000 (maximum 40 TU). Road tests prior to and after the service procedure are allocated 10 TU each (0121 0002 and 0121 0004 respectively). All warranty claims must comply with the Audi Warranty Policies and Procedures Manual.

Important Warnings

Owners should be aware that the vehicle does not actively display any message in the instrument cluster or MMI regarding the brake break-in process or the temporary deactivation of recuperation. The presence of "2022 Audi e-tron DTC C1399F0" is a normal part of this process and will resolve itself once the break-in is complete.

Source: NHTSA Manufacturer Communication 10198161