2022-2024 Audi e-tron GT Brake Pedal Vibration TSB 206847

Bulletin Revision History

Technical Service Bulletin 206847, also identified as 47 23 23 2068205/4, was issued on April 18, 2023. This bulletin supersedes Technical Service Bulletin Group 47 number 22-22 dated December 19, 2022. The latest revision, version 4, included revised service and technical background, revised procedure, and an added model year to the header. Previous revisions on December 19, 2022 (version 3) and November 8, 2022 (version 2) also revised service procedures, warranty information, and added parts and tools.

Symptoms

Owners of 2022-2024 Audi e-tron GT and RS e-tron GT vehicles may experience specific brake system symptoms, including Audi e-tron GT brake pedal vibration. These symptoms are typically reported as:

• During braking at low speeds, a "vibration/pulsation is felt at the brake pedal."
• The "brake response feels 'different'."

This sensation can occur if the vehicle transitions between electric and hydraulic braking, leading to a different pedal feel even if the applied pressure is consistent.

Fault Codes / DTCs

During workshop diagnosis, the following Diagnostic Trouble Code (DTC) may be stored in the ABS/ESC Control Module -J104- (address word 0003):

Code	Description
P05FF00	Brake pressure sensor / Sensor for brake pedal travel deviation

Technical Background

The Audi e-tron GT brake system incorporates several unique functions that can influence brake pedal feel. These include a 'bedding-in routine' for new brake pads, a 'brake refresh' function, and a 'stiffness adaptation routine'.

• Bedding-in routine: New brakes require bedding-in, which the vehicle performs by briefly deactivating the recuperation function. This process can take up to 1,000 miles, depending on driving style.
• Brake refresh function: This function maintains brake friction by applying 500 kJ of braking energy to the mechanical brakes after the vehicle has been stationary for over 12 hours. Recuperation is briefly deactivated during this process.
• Stiffness adaptation routine: During regenerative braking, the system blends electric and hydraulic braking. To ensure smooth blending, the ABS/ESC control unit learns the stiffness of the wheel brakes. This routine involves the electromechanical brake servo building and releasing pressure, causing the brake pedal to move approximately 1 inch. This routine is performed during every charging procedure, takes about 10 seconds, and does not activate the brake lights.

Additionally, the e-tron GT features a smaller brake master cylinder for improved modulation during parking, which can result in generally longer pedal travel when maneuvering. Both brake circuits also open fully at speeds below 12 mph to reduce noise and vibrations, contributing to longer pedal travel. Ceramic brakes may also exhibit inferior friction in wet and cold conditions compared to cast iron brakes.

Repair Procedure Summary

The service procedure for addressing the Audi e-tron GT brake pedal vibration involves several steps to ensure proper brake system function and customer understanding:

1. Bedding-in Routine: Ensure the brake system's bedding-in routine is complete. Once finished, the relevant event memory entry in the ABS/ESC control unit is automatically deleted. For more details, refer to TSB 2063679.
2. Customer Information: Inform the customer about the 'brake refresh' function and other vehicle characteristics, including potentially longer pedal travel during maneuvering and the characteristics of ceramic/tungsten carbide brakes in wet/cold conditions.
3. Owner's Manual: Advise the customer to consult the "Brakes" chapter of their Owner's Manual if needed.
4. Diagnostic Steps (if pedal travel remains unsuitable):
   • Read out the measured value "Adaptation value offset wheel brake stiffness" and upload the ODIS protocol to the GFF database.
   • Run the ODIS test plan "0023 - Brake booster / bleed brakes."
   • Charge the vehicle for at least 60 seconds to ensure the stiffness adaptation routine is performed. Afterward, read out the measured value again and upload the protocol to the GFF database.

Audi is also preparing a new software version for the ABS/ESC control unit to address this issue.

Important Warnings

Owners and technicians should be aware of specific conditions that affect the brake system's adaptation routines:

• "No adaptation procedure is accepted if the brakes are hot or the steering wheel is turned significantly out of the center position."
• "The adaptation procedure is only performed if the temperature of the brake discs is <100°C (212° F) and the temperature of the brake calipers is <55°C (131° F)."
• If your vehicle is outside of the specified warranty period, "this Technical Service Bulletin is informational only," meaning repairs may not be covered.

Warranty Information

Warranty claims for this issue fall under Claim Type 110. Coverage is provided for up to 48 months or 50,000 miles, whichever comes first. If the vehicle is outside of this warranty period, the Technical Service Bulletin serves as informational guidance only.

The service number associated with this bulletin is 4708, with a damage code of 0011. Labor operations include:

• Bleed brake system: 4701 0750
• Diagnostic Time (GFF): 0150 0000 (Max 70 TU)
• Road test prior to service: 0121 0002 (10 TU)
• Road test after service: 0121 0004 (10 TU)

All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual, and are subject to review or audit by Audi Warranty. All part and service references in TSB 2068205 are subject to change.

NHTSA ID: 10235472