2022-2024 Audi A3, S3, RS 3 ABS Magnetic Field Low DTCs

This Technical Service Bulletin (TSB) 2072549/2, released on May 7, 2024, addresses specific diagnostic trouble codes (DTCs) and warning messages that may appear in 2022-2024 Audi A3, S3, and RS 3 models. It supersedes an earlier bulletin, Group 45 number 24-37, dated January 12, 2024, due to updated procedures and warranty information. The primary solution for the Audi A3 ABS magnetic field issue is a software update for the ABS control unit.

Symptoms

Owners of affected 2022-2024 Audi A3, S3, and RS 3 vehicles may observe the following symptoms:

• "Multiple messages" appearing in the instrument cluster.
• A "Pre sense fault message" displayed in the instrument cluster.

Fault Codes / DTCs

Workshop diagnostics may reveal the following Diagnostic Trouble Codes (DTCs) stored in the vehicle's control units:

Code	Description	Module	Address Word
C101AF1	"magnetic field too low"	ABS control unit J104	0003
C101BF1	"magnetic field too low"	ABS control unit J104	0003
C101CF1	"magnetic field too low"	ABS control unit J104	0003
C101DF1	"magnetic field too low"	ABS control unit J104	0003
U112300	"Databus error value received"	Distance Regulation control unit J428	0013
U112200	"Databus implausible message"	Distance Regulation control unit J428	0013

These codes, particularly the Audi A3 ABS magnetic field codes, indicate an issue with the speed sensors' signal or the ABS control unit's interpretation of it.

Diagnosis and Trigger Conditions

The issue is primarily related to the software version of the ABS control unit J104. The TSB notes that improved software has been integrated into production vehicles starting April 2024. For vehicles manufactured before this date, the problem can manifest as the listed DTCs and warning messages.

Important Warnings

Audi has issued critical advisories 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 emphasizes that replacing physical speed sensors will not resolve the underlying software problem and may lead to unnecessary costs.
• Technicians are reminded to "Make sure the speed sensors are free of debris, oil residues, grease, or dirt." While replacement is not the fix, ensuring the sensors are clean can prevent other unrelated issues.

Repair Procedure Summary

The repair for the Audi A3 ABS magnetic field issue involves updating the software of the ABS control unit J104 using the Software Version Management (SVM) system, as detailed in TSB 2011732. The specific steps vary slightly depending on the hardware version of the ABS control unit J104:

For Vehicles with Hardware Version 13 in the ABS Control Unit J104

1. Check the current software version of the brake control unit. If it is lower than 133, run SVM Codes 03A033A followed by 03A033B. These updates will bring the ABS control unit J104 to software version 134.
2. After the previous step is completed, run SVM Code 03A037.
3. If the vehicle is already equipped with software version 133 or 134, only run SVM Code 03A037.
4. Proceed with parking brake basic settings.

For Vehicles with all other hardware versions in the ABS Control Unit J104

1. Delete all DTCs stored in the ABS control unit J104 (address word 0003) and Distance Regulation control unit J428 (address word 0013).
2. Perform a short road test.
3. No additional work is necessary, as the DTCs should not return.

Required Tools or Parts

The primary "tool" for this repair is the Audi diagnostic system capable of performing Software Version Management (SVM) updates. Specific SVM action codes are required:

• SVM Code Input: 03A033A
• SVM Code Input: 03A033B
• SVM Code Input: 03A037

The TSB also lists Old Software Part Numbers (e.g., 5WA614517N, 5WA614517P) and corresponding New Software Part Numbers and versions (e.g., 0134, 0136), which are managed through the SVM process.

Owner Action

If your 2022-2024 Audi A3, S3, or RS 3 is displaying "Multiple messages" or a "Pre sense fault message," or if you suspect an Audi A3 ABS magnetic field issue due to related warning lights, you should contact an authorized Audi dealership. They can diagnose the vehicle, confirm the presence of the relevant DTCs (C101AF1, U112300, etc.), and perform the necessary software update to the ABS control unit J104. This repair is typically covered under warranty for eligible vehicles.

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Source: NHTSA ID: 11002127, Audi Technical Service Bulletin 2072549/2