2022-2024 Audi A3, S3, RS 3 ABS/Pre Sense Fault TSB

Owners of 2022-2024 Audi A3, S3, and RS 3 vehicles may encounter dashboard warnings such as a "Pre sense fault message" or other multiple warning messages in the instrument cluster. These messages are often accompanied by specific diagnostic trouble codes (DTCs) stored in the vehicle's control units. This issue, detailed in Audi Technical Service Bulletin (TSB) 2072549/1, indicates a problem with the ABS control unit and the Distance Regulation control unit, often related to speed sensor readings.

This bulletin, issued on January 12, 2024, provides initial guidance for technicians to address the Audi S3 Pre sense fault and related issues while a more permanent solution is being developed by the manufacturer. It's crucial for owners to understand the recommended steps and warnings provided in this communication.

Symptoms of the Pre Sense Fault

The primary symptom reported by customers is the appearance of "Multiple messages" or a specific "Pre sense fault message" displayed in the instrument cluster. These warnings suggest a malfunction within the vehicle's advanced driver-assistance systems, particularly those relying on sensor data for collision avoidance and adaptive cruise control.

Associated Fault Codes (DTCs)

During diagnosis, technicians may find several specific fault codes stored in the vehicle's control units. These codes help pinpoint the system experiencing the malfunction.

The C101AF1, C101BF1, C101CF1, and C101DF1 codes specifically indicate an issue with one or more speed sensors reporting a "magnetic field too low" condition to the ABS control unit J104. The U112300 and U112200 codes point to communication errors within the vehicle's databus, affecting the Distance Regulation control unit J428.

Important Warnings for Owners

Audi has issued a critical warning regarding this issue: Do not replace speed sensors! Parts replacement does not solve this issue. Claims for replaced parts will be subject to review. This means that replacing the speed sensors will not fix the underlying problem causing the Audi S3 Pre sense fault and could result in unnecessary costs. A permanent production solution is currently under development, and this bulletin provides an interim diagnostic and service procedure.

Initial Diagnostic and Service Steps

For vehicles exhibiting these symptoms and fault codes, technicians are instructed to follow a specific service procedure outlined in TSB 2072549/1:

1. Clear DTCs: All diagnostic trouble codes stored in both the ABS control unit J104 and the Distance Regulation control unit J428 should be deleted.
2. Inspect Speed Sensors: Ensure that the speed sensors are thoroughly cleaned and free from any debris, oil residues, grease, or dirt that might interfere with their operation.
3. Road Test: A short road test must be performed to evaluate the vehicle's performance after the initial steps.
4. Re-check DTCs: After the road test, technicians must check if any of the C101AF1, C101BF1, C101CF1, or C101DF1 DTCs have returned to the ABS control unit. If the codes do not reappear, the vehicle can be released.

This procedure is a temporary measure to address the symptoms while Audi works on a more comprehensive fix. It emphasizes that the issue is not resolved by simply replacing parts.

What Owners Should Know

This Technical Service Bulletin is informational and does not fall under standard Audi Warranty coverage. However, if your vehicle is still within its new vehicle limited warranty period, diagnosis and any necessary interim repairs may be covered. Since a permanent solution is still under development, owners should be aware that the issue might recur. It is advisable to keep records of any service visits related to the Audi S3 Pre sense fault and monitor for future updates from Audi regarding a definitive fix.

Source: NHTSA ID: 10249151