2023-2026 Audi Driver Assist System Fault DTC C12D5FA

Symptoms

Owners of 2023-2026 Audi vehicles may experience issues with their driver assist systems becoming unavailable. This often presents with specific messages displayed on the instrument cluster. These messages typically appear after the vehicle has been driven and then disappear after the ignition is switched off and back on, or after the vehicle enters a bus sleep cycle.

Common instrument cluster messages include:

• "Audi adaptive light: system fault."
• "Audi pre sense: system fault."
• "Adaptive cruise assist: restricted."
• "Adaptive cruise assist: predictive control currently restricted."

If you are seeing these messages, especially if they are intermittent, your vehicle may be affected by the condition described in this TSB, which relates to the Audi e-tron C12D5FA issue.

Fault Codes / DTCs

When these driver assist system faults occur, a specific Diagnostic Trouble Code (DTC) is stored in the Driver assist systems control unit -J1121- (address word 00A5). This DTC is typically sporadic, meaning it does not indicate a permanent hardware failure.

Code	Description	Module	Symptom Number
C12D5FA	Driver assistance systems control module Image processing processor not reacting	Driver assist systems control unit -J1121-	221281

Diagnosis and Trigger Conditions

Technicians may initially find the DTC C12D5FA stored in the Driver assist systems control unit -J1121-. It's important to note that this TSB specifically applies to sporadic issues. If the fault is active/static, or if the DTC C12D5FA is not stored, this bulletin does not apply. The TSB also highlights that the GFF (Guided Fault Finding) system might initially recommend replacing the J1121 control unit, but this is not the correct solution for this specific sporadic fault.

Important Warnings for Owners and Technicians

Audi has issued critical warnings regarding the diagnosis and repair of this specific issue:

• "This TSB does not apply in the event of an active/static issue. The TSB also does not apply if the DTC listed above is not stored." This means the bulletin is only for intermittent faults where C12D5FA is present.
• "Do not replace any parts! Replacing parts will not remedy the customer complaint." This is a crucial instruction. Attempting to replace the Driver assist systems control unit -J1121- or any other components will not resolve the sporadic C12D5FA fault and will result in unnecessary costs.
• "Replacing parts or attempting repairs will not fix the problem. Unjustified labor/replacement parts will be debited." This warning emphasizes that any unauthorized or incorrect repairs will not be covered under warranty, protecting owners from being charged for ineffective solutions related to the Audi e-tron C12D5FA problem.

Repair Procedure Summary

The recommended repair for the sporadic DTC C12D5FA is straightforward and does not involve replacing any hardware. The primary action for technicians is to delete the DTC "C12D5FA: Driver assistance systems control module Image processing processor not reacting" (symptom number 221281) from the Driver assist systems control unit -J1121-.

This simple procedure is intended to clear the sporadic fault and restore full functionality to the driver assist systems. No parts replacement or complex diagnostic steps are required beyond confirming the sporadic nature of the fault and the presence of the specific DTC.

Warranty Information

For vehicles still under warranty, claims submitted for this issue must adhere to the Audi Warranty Policies and Procedures Manual. The Service Number for this bulletin is 9093, and the Damage Code is 0039. The labor operation associated with this fix is 2706 8950, which includes charging the battery. If the vehicle is outside of its warranty period, this Technical Service Bulletin is for informational purposes only.

What Owners Should Do

If your 2023-2026 Audi is displaying intermittent driver assist system warnings and you suspect the Audi e-tron C12D5FA issue, it is recommended to schedule an appointment with an authorized Audi service center. Inform them about the specific warning messages you are seeing and mention Technical Service Bulletin 2076396/1. Be aware that no parts replacement should be necessary for this particular sporadic fault.

---nHTSA ID: 11012511