2022-2026 Audi Start/Stop System Fault TSB 2074810/1

Owners of 2022-2026 Audi vehicles may encounter a specific problem with their start/stop system, especially when the vehicle is relatively new and has accumulated less than 50 km (32 miles). This condition is detailed in Technical Service Bulletin (TSB) 2074810/1, which provides guidance for technicians to resolve the Audi e-tron start/stop fault.

Symptoms

Drivers typically notice the following indications:

• An error message displayed in the instrument cluster, such as: "Start/stop system: system fault. Function unavailable. Please contact workshop"
• Alternatively, the message may read: "Vehicle start system: fault. Please contact workshop"
• The start/stop system does not function as intended.
• These symptoms are most commonly reported when the vehicle's mileage is less than 50 km (32 miles).

Workshop investigations have found that there are usually no specific event memory entries or diagnostic trouble codes (DTCs) stored in the control units that would directly indicate a restriction of the start/stop system's function.

Important Warnings

Audi has issued a critical advisory regarding this issue:

• "The start/stop system is activated automatically after covering 50 km/32 miles."
• "Important: Once the vehicle has a mileage of 50 km/32 miles or more, the start/stop system can no longer be set to 'not active'."

This means that if your vehicle exceeds 50 km (32 miles) before the production mode is deactivated and the start/stop system is activated, the necessary adjustments outlined in TSB 2074810/1 may no longer be possible.

Technical Background

The underlying cause of this Audi e-tron start/stop fault is often related to the vehicle's initial setup. Specifically, the production mode may not have been deactivated, or the start/stop system was not properly activated during the vehicle's first use or pre-delivery inspection. This prevents the system from operating correctly.

Repair Procedure Summary

To resolve the start/stop system fault, technicians follow a specific procedure involving the ODIS diagnostic tester to adjust the engine control unit settings. The process involves two main steps:

1. Deactivating Production Mode: The technician sets adaptation channel 04FC in the engine control unit to "00 00 00" using the ODIS tester. This is followed by cycling Terminal 15 (ignition) OFF, waiting for 10 seconds during the post-run phase, and then turning Terminal 15 ON. This action deactivates the production mode, which also clears any associated EPC (Electronic Power Control) and exhaust emissions warning lamps.
2. Activating the Start/Stop System: The technician then activates the start/stop system by setting adaptation channel $0927: activation of start/stop system: entry to "active" in the engine control unit. After these steps, a road test is performed to confirm that the start/stop system is now fully functional.

Required Tools

The primary tool required for this repair is the ODIS diagnostic tester, which is used to perform the necessary adaptations within the engine control unit.

Warranty Information

For vehicles still under warranty, this repair is typically covered. The claim type is informational if the vehicle is outside of warranty. The service numbers associated with this procedure are 2470 for gas engines and 2360 for diesel engines, with a damage code of 0039. Labor operations include programming the EDC control unit (gas engines) or the electronic injection system control unit (diesel engines), with specific labor times (2360 2599 20 TU for gas, 2470 2599 20 TU for diesel) as per TSB 2074810/1.

All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual.

Additional Information

All part and service references in this TSB are subject to change. Technicians are advised to consult the latest information from the Parts Department and ETKA, as well as the Repair Manual for any fasteners, bolts, nuts, and screws that may require replacement.

NHTSA ID: 11005861