2022-2025 Audi A3/S3/RS3 'Magnetic Field Too Low' DTCs

Owners of 2022-2025 Audi A3, S3, and RS3 vehicles may encounter various warning messages in their instrument cluster, including a "Pre sense fault message." These warnings are often accompanied by specific diagnostic trouble codes (DTCs) indicating issues with the ABS control unit or the Distance Regulation control unit. This issue, identified by Audi Technical Service Bulletin (TSB) 2072549/3, points to a software-related problem rather than a hardware failure.

Symptoms

Owners typically notice the following symptoms related to this issue:

• "Multiple messages/Pre sense fault message in the cluster."

Fault Codes / DTCs

Technicians diagnosing the issue will find specific fault codes stored in the vehicle's control units:

Code	Description	Module Affected
C101AF1	"magnetic field too low"	ABS control unit J104
C101BF1	"magnetic field too low"	ABS control unit J104
C101CF1	"magnetic field too low"	ABS control unit J104
C101DF1	"magnetic field too low"	ABS control unit J104
U112300	"Databus error value received; Databus implausible message"	Distance Regulation control unit J428
U112200	"Databus error value received; Databus implausible message"	Distance Regulation control unit J428

Diagnosis

The presence of the DTCs C101AF1, C101BF1, C101CF1, C101DF1 in the ABS control unit J104 (address word 0003) or DTCs U112300, U112200 in the Distance Regulation control unit J428 (address word 0013) indicates the need for this TSB's procedure. The underlying cause is an improved software solution that was implemented in production vehicles starting in April 2024.

Important Warnings

Audi explicitly states a critical warning regarding this issue:

• "Do not replace speed sensors! Parts replacement does not solve the issue. Claims for replaced parts will be subject to review."

This means that replacing speed sensors will not fix the problem and will likely result in a denied warranty claim. The solution is purely software-based.

Repair Procedure Summary

The repair involves updating the software of the ABS control unit J104 using the Software Version Management (SVM) system. The TSB, identified as 2072549/3, provides detailed instructions for this process. The SVM action code required is 2011732.

For vehicles equipped with hardware version 13 in the ABS Control Unit J104 (excluding RS3 models), the technician must first check the current software version of the brake control unit. If it is lower than 133, SVM Codes 03A033A followed by 03A033B must be run. These updates will bring the ABS control unit J104 to software version 134. Afterward, SVM Code 03A037 should be run. If the vehicle already has software version 133 or 134, only SVM Code 03A037 is required. Finally, parking brake basic settings must be performed.

For vehicles with all other hardware versions in the ABS Control Unit J104 (including RS3 models), the procedure is simpler. All stored DTCs in the ABS control unit J104 and Distance Regulation control unit J428 must be deleted. A short road test is then performed. No additional work is necessary, and the DTCs should not return.

Warranty Information

This repair is covered under Audi's warranty for up to 48 months or 50,000 miles. For Certified Pre-Owned (CPO) vehicles, coverage is under G10, provided the owner is verified. If the vehicle is outside of warranty, this Technical Service Bulletin serves as informational guidance only. The service number for this claim is 4545, with a damage code of 0039. Diagnostic time for a software update is typically 0151 0010, with specific times for different hardware versions (Max 70 TU for hardware version 13, Max 30 TU for other versions). A road test before the procedure has no allowance, while a road test after the procedure has a 10 TU allowance.

Owner Action

If your 2022-2025 Audi A3, S3, or RS3 is displaying "Multiple messages/Pre sense fault message in the cluster" or you suspect issues related to the "Audi S3 magnetic field too low DTCs", you should contact your authorized Audi dealership. Inform them about the symptoms and mention TSB 2072549/3. The dealership will perform the necessary software update to resolve the issue.

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Source: NHTSA ID: 11002897