2022-2024 Audi e-tron GT Brake System Software Update 49A4

Audi has released Technical Service Bulletin (TSB) 49A4 to address specific concerns regarding the brake system in 2022-2024 Audi e-tron GT and RS e-tron GT models. This update proactively prevents conditions that can lead to an Audi e-tron GT brake system noise or increased brake pedal travel.

The TSB, released on March 21, 2024, outlines a software update for the brake electronics and a subsequent brake system bleed to resolve these issues. This is a proactive measure to ensure optimal brake performance and driver comfort.

Symptoms

Owners of affected 2022-2024 Audi e-tron GT and RS e-tron GT vehicles may notice the following symptoms related to their brake system:

• Loud operating noises from the hydraulic unit: The hydraulic unit may produce sounds that are louder than what is typically expected.
• Increased brake pedal travel at very low speeds: The brake pedal might feel like it travels further than usual before engaging effectively, particularly when the vehicle is moving slowly.

These conditions are addressed by the software update and brake system bleed outlined in TSB 49A4, aiming to restore normal brake system operation and eliminate the Audi e-tron GT brake system noise.

Fault Codes / DTCs

After the SVM (Software Version Management) update, technicians may encounter a specific fault code related to the parking brake system:

• C10E1F2: "Parking brake motor position not plausible"

If this fault code is present and cannot be cleared, it must be addressed by performing the "0003 - Brake Button Initiation" test plan through the guided functions of DA 0003 before proceeding with the brake system bleeding steps.

Important Warnings for Owners and Technicians

This TSB includes several critical warnings to ensure safety and proper repair:

• Radiator Fan Operation: "Radiator Fan(s) may cycle ON high speed during the Update Process! There is a serious risk that personal injury may result if contact is made with spinning fan blades. Keep hands and all objects away from Radiator Fan(s) during Update Process!" This emphasizes the danger of moving fan blades during the update.
• Warranty Claim Reimbursement: "A warranty claim may not be reimbursed if there is no confirmation response to support the claim." This highlights the importance of completing the SVM process entirely.
• Diagnostic Tool Connection: The VAS Diagnostics Interface "MUST ONLY be connected to the tester with a USB cable." Using Bluetooth or WiFi for software updates increases the risk of connection loss and potential control module damage, and can lead to denial of additional time requests.
• Guided Fault Finding (GFF): "DO NOT USE Guided Fault Finding (GFF) to perform this flash." Using GFF will make the flash procedure take longer, and requests for additional time will not be considered.
• Brake Bleeding Test Plan: During brake bleeding procedures, if the test plan shows "False result" or "Unknown status," this is normal. "Do not press the complete/continue button! If used, the test plan will fail." Allow the test plan to automatically continue.
• In-cabin Warnings During Bleed: "While performing brake bleeding steps, there will be several warnings that appear in the instrument cluster and MMI, these can be ignored." This advises technicians not to be alarmed by temporary warning messages.
• No Road Test Required for C10E1F2: If DTC C10E1F2 is present, the test plan will indicate a road test is required. However, "A road test is not required as there were not any parking brake components replaced."

Repair Procedure Summary

The repair process for TSB 49A4 involves two main sections: a software update to the brake electronics and a comprehensive brake system bleed.

Section A – Brake Electronics Software Update

1. Preparation: Ensure the ODIS software is up to date, a battery charger (minimum 90 Amp continuous supply) is connected to maintain voltage above 12.5 volts, and screen saver/power saving settings are off on the diagnostic tester. The VAS Diagnostic Tester must be plugged in via its power adapter and connected to the vehicle with a USB cable.
2. Software Update: The technician will select "SVM – Code Input" in ODIS and enter SVM code 49A4A144. They will follow on-screen prompts to update the brake electronics software.
3. Parking Brake Position Detection: If the message "Electromechanical parking brake: not in position" appears in the MMI after the SVM update, the technician will follow the on-screen instructions: "Please press the brake pedal and start the position detection function. This can also be done later by going to Vehicle > Settings & Service > Electromechanical parking brake." They will then select "Detect parking brake position."

Section B – Brake System Bleeding

1. DTC C10E1F2 Check: After the SVM update, the vehicle is scanned for fault code C10E1F2 ("Parking brake motor position not plausible"). If present and not clearable, the technician performs the "0003 - Brake Button Initiation" test plan.
2. Brake System Bleed Steps: The brake system is bled in three stages:
   • Conventional Brake Bleeding: Performed according to the ELSA Repair Manual, referencing the "Conventional bleeding" section.
   • NX6 Brake Booster Bleeding: Performed via ODIS using test plan "0023 - Brake Boost / brake bleeding." Technicians are advised to ignore "False result" or "Unknown status" messages during this process.
   • Service Bleeding Procedure: Performed via ODIS using test plan "0003 - Service Bleeding." Again, "Unknown status" is normal. The test plan requires applying and releasing the brake pedal cyclically until conditions are met.
3. Post-Bleed: After bleeding, the vehicle undergoes a bus sleep procedure (disconnecting the diagnostic tester, removing the key, locking the vehicle for 5 minutes) and fault memory is erased.

Required Tools and Parts

To perform TSB 49A4, specific tools and parts are required:

• Brake Fluid: Up to 4.5 liters of DOT 4 brake fluid (Part Number: B 000750S0).
• Battery Tester/Charger: Capable of a minimum 90 Amp continuous supply.
• Diagnostic Tester: VAS6150X/VAS6160X or equivalent.
• Brake Filling and Bleeding Equipment: VAS6860 or equivalent.
• Brake Bleeding Tool Set: VAS6564 or equivalent.
• Wrench - Brake Bleeder Set: VAS5519 or equivalent.

Warranty Information

This update is covered under warranty, provided the vehicle is within its New Vehicle Limited Warranty and shows the 49A4 code in the Elsa Campaign/Action Information screen. The service number for this campaign is 49A4, with Damage Code 0099 and Parts Vendor Code 002. Claim types are 710 for sold vehicles and 790 for unsold vehicles. The causal indicator should be marked as "labor as causal." Technicians must attach an Elsa printout showing the "open" status to the repair order for reimbursement.

Owner Action

If you own a 2022-2024 Audi e-tron GT or RS e-tron GT and experience an Audi e-tron GT brake system noise from the hydraulic unit or increased brake pedal travel at low speeds, you should contact an authorized Audi dealer. They will be able to verify if your vehicle is eligible for this software update and brake system bleed under TSB 49A4. This procedure is performed under warranty.

NHTSA ID: 10252010