2021-2022 Audi A6/A7 Steering Warning TSB

Owners of 2021-2022 Audi A6, A6 allroad, S6, RS 6, A7, A7 PHEV, S7, and RS7 vehicles may experience a Audi A6 steering warning message in their instrument cluster. This warning is often accompanied by an increased effort required to steer the vehicle, indicating a potential problem with the power steering system.

Audi Technical Service Bulletin (TSB) 94 22 55 2065605/1, issued on January 7, 2022, details the diagnosis and repair for this specific condition. The root cause has been identified as oxidation at the coupling point (TMR T1c/T1cx) to the electromechanical steering rack, which affects the power steering module.

Symptoms

If you own an affected Audi model, you might observe the following symptoms:

• A "Warning message relating to the steering is displayed in the instrument cluster."
• "Increased effort may be needed to steer the vehicle."

These symptoms point to a potential issue with the vehicle's power steering system, which can impact driving safety and comfort.

Fault Codes / DTCs

During workshop diagnosis for the Audi A6 steering warning, technicians often find various diagnostic trouble codes (DTCs) stored. These codes are typically related to the power steering module, identified as J500 (diagnostic address 0044). While the TSB does not list specific DTCs, their presence confirms an electronic fault within the steering system.

Diagnosis and Technical Background

The primary cause of the Audi A6 steering warning and steering effort issues is oxidation. The contact points within the connector housing for the electromechanical steering rack become oxidized due to moisture ingress. This corrosion disrupts the electrical signals to the power steering module (J500), leading to the observed symptoms and stored DTCs.

Technicians will inspect the connector T1c/T1cx at the TMR station for signs of oxidation. This visual inspection is crucial for confirming the diagnosis before proceeding with repairs.

Repair Procedure Summary

The repair outlined in TSB 94 22 55 2065605/1 involves replacing the oxidized repair cable. The procedure generally follows these steps:

1. De-energize the 12V system: This is a critical safety step before starting any electrical work.
2. Inspect for oxidation: Confirm that the connector T1c/T1cx at the TMR station is oxidized. If the connector on the steering side of the harness (T1cx) is also affected, the steering harness section may need replacement.
3. Replace the repair cable: Route the new repair cable from the central fuse (fuse D, 125A) on the 12V battery along the original wiring to the front right longitudinal member.
4. Secure the new cable: Wrap adhesive tape (N 107 290 02) around the new repair cable in specific areas to prevent chafing or noise.

Important Note: This repair DOES NOT require the entire body harness to be replaced, which can save significant time and cost. The old cable can remain in the vehicle, and only specific areas of the new repair cable need to be wrapped in tape to keep it in place and prevent noise.

Required Parts and Tools

To address the Audi A6 steering warning issue, specific repair cables and materials are required. It's important to use the parts listed in this TSB, as they may differ from those in ETKA and include superseding part numbers.

Part Number	Part Description	Quantity
4K1 974 177 A	Repair cable only for OK3 + LOL (high-voltage vehicles with left-hand drive)	01
4K1 974 177	Repair cable only for OK4 + LOL (48V vehicles with left-hand drive)	01
N 107 290 02	Adhesive tape	0.25
5G0886373	Grommet for rear seat bench	02

Additional fasteners, bolts, nuts, and screws may be needed as per the Repair Manual and ETKA/ELSA.

Warranty Information

For vehicles experiencing the Audi A6 steering warning and related issues, warranty coverage for this repair is typically available:

• Standard Warranty: Up to 48 months or 50,000 miles.
• Certified Pre-Owned (CPO) Vehicles: Covered under G10, requiring owner verification.
• Out of Warranty: If your vehicle is outside of any warranty, this Technical Service Bulletin is informational only, meaning the repair costs would be the owner's responsibility.

All warranty claims submitted for payment must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review by Audi Warranty.

NHTSA ID: 10207164