2021-2026 Audi Adaptive Light System Malfunction TSB

Symptoms

Owners of affected Audi vehicles may experience various issues related to the driver assistance systems. These symptoms often point to an Audi e-tron adaptive light system malfunction or similar problems in other models.

Commonly reported symptoms include:

• The instrument cluster displaying warning messages such as "Audi adaptive light: system fault," "Audi pre sense: system fault," "Adaptive cruise assist: restricted," or "Adaptive cruise assist: predictive control currently restricted."
• Driver assist systems becoming unavailable.
• High beam automatic headlamp control failing to switch off/disconnect, having no function, or activating unexpectedly.
• The cornering light indicator display activating without cause.
• The bulb failure information display activating without cause.
• The high beam indicator display activating without cause.
• The cornering lamp operating incorrectly, having no function, or being partially out of order.
• The headlamp range control system operating with an incorrect sequence.

Fault Codes / DTCs

When diagnosing an Audi e-tron adaptive light system malfunction, technicians may find specific diagnostic trouble codes (DTCs) stored in the vehicle's control modules. The primary fault code associated with this issue is:

This DTC C12B3FA is typically stored intermittently in the J1121 control module, which is the front sensor for driver assistance systems, and is associated with symptom code 221189.

Technical Background

Audi's Technical Service Bulletin 2054202/6 explains that the DTC C12B3FA, indicating a communication error with the driver assistance systems front camera (J1121), can appear intermittently. This communication fault is often triggered by external influences, such as electromagnetic compatibility (EMC) issues, rather than a physical defect in the camera itself. Audi has implemented a robustness measure from software version SW0295 onwards to mitigate this complaint in production vehicles.

Repair Procedure Summary

The TSB outlines a specific repair procedure depending on the software version of the J1121 driver assist systems control unit (diagnostic address 00A5).

• For vehicles with software versions below SW0295: Technicians are instructed to follow the guidelines detailed in TSB 2063497. This bulletin addresses various driver assist system malfunctions, including those related to B200FF9, B200FF3, and C123FB.
• For vehicles with software versions SW0295 and above: The recommended action is to simply delete the stored DTC C12B3FA. After the DTC is cleared, the issue is expected to be resolved and is unlikely to reoccur. No further measures are typically necessary, as the problem should clear after a bus sleep cycle and a restart of the J1121 control unit.

It is important to note that the TSB explicitly states that replacing the R242 front camera for the assistance systems does not resolve this issue. Claims for replaced parts will be subject to review, indicating that unnecessary part replacements should be avoided.

Owner Action

If your Audi vehicle is displaying an "Audi adaptive light: system fault" message, or if you are experiencing other driver assist system warnings that suggest an Audi e-tron adaptive light system malfunction, it is advisable to schedule an appointment with an authorized Audi service center. Technicians can diagnose the issue, check for the presence of DTC C12B3FA, and apply the appropriate software-based remedy as outlined in TSB 2054202/6. This TSB is informational and generally not applicable to Audi Warranty, which means that diagnosis or repair costs may apply if your vehicle is outside its warranty period.