2019-2026 Audi Adaptive Light System Malfunction TSB

Symptoms of an Adaptive Light System Malfunction

Owners of affected Audi vehicles may experience issues with driver assistance systems becoming unavailable. The instrument cluster might display specific warning messages, indicating a problem with the adaptive lighting or other related systems. These symptoms are often linked to the presence of DTC C12B3FA.

Reported symptoms include:

• "Audi adaptive light: system fault" message (as shown in Figure 1 of the original TSB).
• "Audi pre sense: system fault" message.
• "Adaptive cruise assist: restricted" message.
• "Adaptive cruise assist: predictive control currently restricted" message.

These messages indicate that the driver assist systems are not functioning correctly, which can impact safety and convenience features.

Fault Codes / DTCs

The primary diagnostic trouble code (DTC) associated with this issue is stored intermittently in the J1121 control module for driver assistance systems (diagnostic address 00A5).

This DTC, C12B3FA, specifically points to a communication error with the front camera, which is a critical component for many driver assistance features, including the adaptive light system.

Diagnosis and Trigger Conditions

The DTC C12B3FA, indicating a communication error with the front camera, may appear intermittently. This issue is often triggered by external influences, such as electromagnetic compatibility disturbances. The TSB notes that this condition can lead to the "Audi adaptive light system malfunction" message and other driver assistance system warnings.

For vehicles with software version SW0295 or higher, the issue may resolve itself after a bus sleep cycle and a restart of the J1121 driver assist systems control unit. This suggests that the problem is often transient and software-related rather than a persistent hardware failure.

Repair Procedure Summary

The repair procedure focuses on checking the software version of the J1121 driver assist systems control unit (diagnostic address 00A5).

1. Check Software Version: Technicians must first determine the current software version installed on the J1121 control unit.
2. Software Version Below SW0295: If the software version is found to be below SW0295, the technician should follow the instructions outlined in TSB 2063497. This separate TSB addresses various driver assist system malfunctions, including issues like aLDW performance and ACC inoperation.
3. Software Version SW0295 or Higher: For vehicles with software version SW0295 or higher, no further specific measures are typically necessary. The issue is expected to resolve after a bus sleep cycle and a restart of the J1121 control unit. The TSB explicitly states that if parts are changed or replaced under warranty without good reason, the costs may be charged back.
4. Important Notice: It is crucial to note that replacing the R242 front camera for the assistance systems will not solve this issue, even if suggested by the Guided Fault Finding system. The problem is primarily software-related or an intermittent communication problem.

This TSB, 2054202/7, provides guidance for addressing the 2021 Audi e-tron manufacturer_communication regarding the adaptive light system.