2021-2026 Audi Driver Assist System Fault TSB

Symptoms

Owners of affected Audi vehicles may observe various warning messages or malfunctions related to driver assistance systems. These symptoms are typically intermittent and may include:

• "Audi adaptive light: system fault"
• "Audi pre sense: system fault"
• "Adaptive cruise assist: restricted"
• "Predictive control currently restricted"
• Distance regulation indicator display (ACC) malfunctions
• Automatic headlamp control or high beam automatic headlamp control issues
• Traffic sign detection display error messages
• Exterior lighting malfunction indicators
• Adaptive headlamp/cornering lamp malfunction display
• Predictive efficiency assist indicator warnings
• Cruise control system (ADR, ACC) malfunction display
• Adaptive distance regulation (ADR) indicator display
• Dynamic curve light malfunctions

These messages often disappear after cycling the ignition off and on, or after the vehicle enters a bus sleep cycle.

Fault Codes / DTCs

When these symptoms occur, diagnostic scans may reveal specific fault codes stored in the vehicle's control units. The primary diagnostic trouble code associated with these intermittent issues is:

| Code | Description | Module | | :--- | :---------- | | C12D5FA | Driver Assistance Systems Control Module Image processing processor not reacting | 00A5 - Front sensor for driver assistance systems |

This DTC indicates a sporadic issue with the image processing within the front sensor for driver assistance systems.

Diagnosis and Trigger Conditions

Audi Technical Service Bulletin 2076396/2 identifies the root cause as an intermittent fault within the Driver assist systems control unit -J1121-. This unit, specifically the 00A5 - Front sensor for driver assistance systems, may sporadically report that its image processing processor is not reacting, leading to the DTC C12D5FA. The TSB emphasizes that this is a sporadic, not active or static, issue. The warnings and associated fault codes are temporary and resolve themselves after an ignition cycle or bus sleep, indicating a transient condition rather than a persistent hardware failure.

Repair Procedure Summary

For the Audi e-tron C12D5FA fault, Audi Technical Service Bulletin 2076396/2 outlines a straightforward resolution. The recommended procedure is to delete the DTC C12D5FA from the Driver assist systems control unit -J1121-. It is critical to note that the TSB explicitly states that replacing any parts, including the Driver assist systems control unit -J1121- or the Front sensor for driver assistance systems, will not fix this intermittent problem. Attempting such replacements is considered unjustified and may result in the dealer being debited for parts and labor. The repair focuses solely on clearing the sporadic fault code after confirming its presence through diagnostic tools.

Owner Action

If your 2021-2026 Audi vehicle is displaying intermittent warnings such as "Audi adaptive light: system fault," "Audi pre sense: system fault," or "adaptive cruise assist restricted," and these messages clear after restarting the vehicle, you should contact your authorized Audi dealership. Inform them about the intermittent nature of these warnings and reference Technical Service Bulletin 2076396/2. This TSB specifically advises against part replacement for the Audi e-tron C12D5FA fault. Your dealer will perform diagnostic checks to confirm the sporadic DTC C12D5FA and then clear the fault code. This service is typically covered under warranty if your vehicle is eligible.