2022-2024 Audi e-tron GT DTC C1399F0 ABS Module Fault

Audi has issued Technical Service Bulletin (TSB) 2063679/4 to address specific braking system concerns in 2022-2024 Audi e-tron GT and RS e-tron GT models. This bulletin, dated January 12, 2024, supersedes Technical Service Bulletin Group 45 number 22-24, which was dated May 20, 2022. The update includes revisions to the header and warranty claim types.

This TSB provides guidance for technicians when the diagnostic trouble code (DTC) C1399F0 is stored in the Anti-lock Braking System (ABS) control module. The bulletin details the conditions under which this fault code may appear and outlines the necessary steps to resolve the issue, ensuring proper brake function and energy recuperation for the Audi e-tron GT C1399F0 issue.

Symptoms

Owners of 2022-2024 Audi e-tron GT and RS e-tron GT vehicles may notice one of the following conditions:

• "Recuperation too low when braking on new vehicle."
• Reduced recuperation efficiency after brake discs or brake pads have been replaced.

These symptoms are often linked to a specific diagnostic trouble code stored in the ABS control module.

Fault Codes / DTCs

When the above symptoms are present, workshops may find the following diagnostic trouble code stored in the ABS control module, specifically module -J104- (address word 0003):

Technical Background

Audi has implemented a new brake application mode for bedding in new brake pads on the disc. This mode is designed to ensure proper break-in of the braking components. It can be initiated by technicians using the Test Plan "003 Brake-In Service Pads".

During this brake application mode, the vehicle's recuperation function is temporarily deactivated, and braking is performed manually. The DTC C1399F0 is logged in the ABS control module, J104, to indicate that this special mode is active. The breaking-in process occurs when the brakes are applied while driving, and it is not actively displayed to the customer in the instrument cluster or the MMI. The mode and the DTC C1399F0 are automatically deactivated once the required amount of energy has been reached, signaling the completion of the break-in process.

Repair Procedure Summary

If brake discs and/or brake pads have been replaced, or if the DTC C1399F0 is present, technicians should follow these steps:

1. Select Test Plan: Using the ODIS diagnostic system (via Guided Functions or GFF), select the Test Plan titled "003 Break-in service brakes."
2. Reevaluate and Release: After performing the Test Plan, reevaluate the vehicle's systems and then release it.

This procedure ensures that the brake components are properly bedded in and that the special brake application mode is correctly deactivated, resolving the Audi e-tron GT C1399F0 condition.

Warranty Information

Warranty claims for this procedure must adhere to the Audi Warranty Policies and Procedures Manual. The following details apply:

• Claim Type: 110 (up to 48 Months/50,000 Miles).
• Service Number: 4708
• Damage Code: 0011
• Diagnostic Time: GFF (0150 0000), with time stated on the diagnostic protocol (Maximum 40 TU).
• Road test prior to service procedure: No Allowance (0 TU).
• Road test after service procedure: No Allowance (0 TU).
• Claim Comment: As per TSB 2063679/4.

Important Warnings

Owners should be aware that if their vehicle is outside the specified warranty period (48 months or 50,000 miles), this Technical Service Bulletin is for informational purposes only. In such cases, the repair may not be covered under warranty, and associated costs could apply.

NHTSA ID: 10249673