2021 Audi Quattro Ultra Drivetrain Noises TSB

Audi has issued Technical Service Bulletin (TSB) 39 21 43 2059057/4 to address customer complaints regarding drivetrain noises and vibrations in certain 2021 Audi Quattro Ultra models. This TSB, dated July 16, 2021, supersedes an earlier bulletin, Group 39 number 21-40, from February 26, 2021, with revisions to include additional model years and expanded repair procedures.

This bulletin specifically applies to 2021 Audi A4, A5, A6, A7, and Q5 vehicles equipped with the Quattro Ultra all-wheel-drive system. The 2021 Audi Quattro Ultra drivetrain noises are a known concern that Audi is actively addressing.

Symptoms

Owners of affected vehicles may experience the following symptoms related to the 2021 Audi Quattro Ultra drivetrain noises:

• "Noises from the drive train when pulling away quickly from a stop with the wheels turned."
• "Vibrations, humming, droning, or rubbing when fully turning the steering wheel in the vehicle interior and/or on the rear seats can be heard and felt."

These symptoms are typically reproducible by technicians and can be traced to the all-wheel-drive clutch, propeller shaft, or rear differential.

Diagnosis and Trigger Conditions

The technical background for these 2021 Audi Quattro Ultra drivetrain noises stems from the varying speeds between the front axle differential and the rear final drive. When the vehicle is in a very tight corner with the four-wheel-drive clutch 1 closed, this can lead to humming, drumming, or other vibrations.

An important diagnostic note is that there are typically no Diagnostic Trouble Codes (DTCs) stored in the Transmission Control Module (TCM), identified as J217 (address word 0002), or in the All-Wheel-Drive Control Module, J492 (address word 0022), even when the symptoms are present.

Important Warnings for Owners

If your vehicle undergoes the initial repair procedure (ATF oil change), please be aware of the following:

• The condition may take up to 60 miles of driving before it is fully corrected. Do not pursue further repair steps if the issue persists immediately after the oil change; instead, drive the vehicle for at least 60 miles first.

Repair Procedure Summary

The repair procedure outlined in TSB 39 21 43 2059057/4 involves a two-stage approach, starting with an all-wheel-drive clutch fluid exchange and potentially escalating to clutch replacement if the initial repair is unsuccessful.

Stage 1: All-Wheel-Drive Clutch ATF Exchange

1. Initial Assessment: Technicians will first attempt to reproduce the customer's concern and check the vehicle's repair history. If the TSB has already been performed and the vehicle driven over 60 miles, they will skip to the clutch replacement stage.
2. Preparation: Ensure the S-tronic or manual transmission is at operating temperature.
3. Diagnosis Log: Using ODIS Guided Functions, technicians will access the All-Wheel Drive Electronics (address 0022), read measured values, and upload a diagnosis log to GFF Paperless.
4. ATF Drainage & Documentation: The ATF from four-wheel-drive clutch 1 is completely drained. Technicians are instructed to document the ATF quality with photos (including date stamp and VIN reference) before disposal.
5. First ATF Fill: New ATF (part number G 055 515 A2) is filled, and the level is set according to the repair manual, reusing the sealing bolts.
6. Driving & Cooling Cycles: The vehicle is driven to achieve operating temperature, then allowed to cool for at least 30 minutes. This cycle is repeated.
7. Second ATF Drainage & Fill: The ATF is drained again, and new ATF (part number G 055 515 A2) is filled, this time replacing the sealing bolts.
8. Final Steps: Another drive cycle to operating temperature, followed by a 30-minute cool-down. The basic setting for "Reset learnt values for oil ageing" is performed using ODIS Guided Functions or Self Diagnosis, targeting All-Wheel Drive Electronics (address 0022).
9. Test Drive: A final test drive confirms normal operation. If the issue is resolved, the vehicle is released to the customer.

Stage 2: All-Wheel-Drive Clutch Replacement (If Needed)

If the 2021 Audi Quattro Ultra drivetrain noises persist after the ATF exchange and the vehicle has been driven for at least 60 miles, the next step is to replace the All-Wheel Drive Clutch assembly. This procedure is performed according to the Elsa repair manual. The repair is concluded by using ODIS Guided Functions, All-Wheel Drive Electronics (address 0022) to perform the "Replace control module" function.

Required Tools or Parts

For the ATF exchange procedure (Steps 1-16):

• G 055 515 A2: Transfer box gear oil (ATF) (Quantity: 02)
• N 90281802: Seal Bolt (combination) (Quantity: 02)
• See ETKA: Fasteners, Bolts, Nuts, and Screws as needed per the Repair Manual

For replacing the All-Wheel Drive Clutch (Steps 17-18):

• Order to VIN: Four Wheel Coupling (Quantity: 01)
• N 91239202: Bolt Hexagon socket flat head bolt M8 x 100 (Quantity: 01)
• N 10739501: Bolt Hexagon socket flat head bolt M8 x 70 (Quantity: 03)
• See ETKA: Fasteners, Bolts, Nuts, and Screws as needed per the Repair Manual

Warranty Information

This repair is covered under Audi's warranty for up to 48 months or 50,000 miles, whichever comes first. For Certified Pre-Owned (CPO) vehicles, coverage falls under G10. If the vehicle is outside of warranty, this Technical Service Bulletin serves as informational guidance only. The Service Number for claims is 3960, and the Damage Code is 0020. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual, referencing TSB #2059057/4.

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Source: NHTSA ID 10199368