2022-2024 Audi A3/S3/RS 3 Magnetic Field Too Low TSB

Owners of 2022-2024 Audi A3, S3, and RS 3 vehicles may encounter various warning messages related to the braking system, including an "ABS malfunction display" or "emergency brake function display." These warnings are often accompanied by diagnostic trouble codes (DTCs) indicating an "Audi magnetic field too low" condition within the ABS control unit. This Technical Service Bulletin (TSB) 2072549/4, released by Audi, provides a comprehensive solution for these issues, which are primarily caused by a software anomaly.

The TSB 2072549/4 was officially released on September 23, 2025, with previous revisions indicating ongoing updates to the repair procedure and warranty information. The core problem stems from a software issue in the brake control unit, which can lead to erroneous fault detections related to the speed sensors.

Revision History

This Technical Service Bulletin has undergone several revisions to refine the service procedure and warranty details:

• Revision 4: Updated procedure and warranty table.
• Revision 3 (June 11, 2024): Revised service procedure and updated warranty table.
• Revision 2 (May 7, 2024): Revised service procedure and added warranty table.

Symptoms

Owners may observe several symptoms related to this issue, often appearing as warning messages in the instrument cluster. These can include:

• "ABS malfunction display" activating without cause.
• "emergency brake function display" responding sporadically.
• "ABS malfunction display" activating without cause.
• "emergency brake function display" activating without cause.
• "ABS malfunction display" functionality does not switch off or disconnect.
• "emergency braking function warning indicator" activating without cause.
• "Multiple messages/Pre sense fault message in the cluster."

These messages indicate that the vehicle's braking or safety systems are reporting a fault, even when no actual mechanical issue is present.

Fault Codes / DTCs

The primary diagnostic trouble codes associated with this condition, indicating an "Audi magnetic field too low" fault, are stored in the ABS control unit J104 (address word 0003). These codes point to an incorrect reading or interpretation of magnetic field data from the speed sensors.

Code	Description	Module
C101AF1	"magnetic field too low" stored in ABS control unit	ABS control unit J104
C101BF1	"magnetic field too low" stored in ABS control unit	ABS control unit J104
C101CF1	"magnetic field too low" stored in ABS control unit	ABS control unit J104
C101DF1	"magnetic field too low" stored in ABS control unit	ABS control unit J104

Diagnosis and Trigger Conditions

Diagnosis typically involves scanning the vehicle's control units for stored DTCs. The presence of C101AF1, C101BF1, C101CF1, or C101DF1 in the ABS control unit J104 confirms the condition. The issue is a software fault within the brake control unit that causes these erroneous readings, leading to the "Audi magnetic field too low" error. Improved software has been implemented in production vehicles starting from April 2024.

Important Warnings

Audi has issued specific warnings for technicians and owners regarding this TSB:

• Speed Sensor Condition: Technicians must ensure that the speed sensors are free of debris, oil residues, grease, or dirt before proceeding with any repair. This ensures that the problem is indeed software-related and not due to external contamination.
• Parts Replacement: "Do not replace speed sensors! Parts replacement does not solve the issue. Claims for replaced parts will be subject to review." This is a critical warning for owners, as replacing speed sensors will not resolve the underlying software problem and could lead to unnecessary repair costs. The TSB explicitly states that such claims will be reviewed, implying they may not be covered under warranty if the sensor replacement was performed incorrectly.

Repair Procedure Summary

The repair procedure outlined in TSB 2072549/4 varies slightly depending on the hardware version of the ABS control unit J104. The underlying cause, an "Audi magnetic field too low" condition, is addressed by either a software update or clearing DTCs.

For Vehicles with Hardware Version 13 in the ABS Control Unit J104 (Except RS3)

1. Software Version Check: The technician will first check the current software version of the brake control unit. If the software version is lower than 133, a software update is required.
2. Software Update: The SVM Codes 03A033A and 03A033B are run consecutively. These updates will bring the ABS control unit J104 to software version 134.
3. Additional SVM Code: After the initial software update, SVM Code 03A037 must be performed.
4. Existing Software: If the vehicle is already equipped with software version 133 or 134, only SVM Code 03A037 needs to be run.
5. Parking Brake Settings: Finally, the technician will proceed with parking brake basic settings to complete the repair.

For Vehicles with All Other Hardware Versions in the ABS Control Unit J104 (Including RS3)

1. DTC Deletion: All diagnostic trouble codes stored in the vehicle are deleted.
2. Road Test: A short road test is performed to verify the resolution of the issue.
3. No Additional Work: For these vehicles, no further work is necessary, as the DTCs are expected not to return after being cleared and verified.

Warranty Information

This Technical Service Bulletin (TSB 2072549/4) outlines specific warranty claim procedures for addressing the "Audi magnetic field too low" condition.

• Claim Type: If the vehicle is outside of any warranty, this TSB is informational only.
• Service Number: The service number associated with this bulletin is 4545.
• Damage Code: The damage code for this issue is 0039.
• Claim Comment: Claims should include the comment "As per TSB 2072549/4."

Labor Operations

Specific labor operations and time units are provided for warranty claims:

For Vehicles with Hardware Version 13 in the ABS Control Unit J104 (Except RS3):

• Software Update: Labor operation code 0150 0010. Refer to the Service Repair Time (SRT) with associated operations.
• Software Update: Labor operation code 0150 0060. Time is stated on the diagnostic protocol.

For Vehicles with Hardware Other Than Version 13 (or RS3):

• GFF (Guided Fault Finding): Labor operation code 0150 0010. Refer to the SRT with associated operations.
• GFF (Guided Fault Finding): Labor operation code 0150 0060. Time is stated on the diagnostic protocol.

For All Vehicles:

• Road Test after the service procedure: Labor operation code 0121 0004, allocated 10 Time Units (TU).

All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review or audit by Audi Warranty.

Owner Action

If your 2022-2024 Audi A3, S3, or RS 3 displays any of the described warning messages, such as "ABS malfunction display" or "emergency brake function display," or if you suspect an "Audi magnetic field too low" issue, it is recommended to schedule an appointment with an authorized Audi dealer. They will be able to diagnose the vehicle, confirm the presence of the relevant DTCs (C101AF1, C101BF1, C101CF1, C101DF1), and apply the appropriate software update or procedure as outlined in TSB 2072549/4. This service is typically covered under warranty if your vehicle meets the eligibility criteria.

NHTSA Source: TSB 2072549/4