2022-2026 Audi ABS/ESC Implausible Signal TSB

Audi has released Technical Service Bulletin (TSB) 45 24 46 2072304/2 to address an "implausible signal" from the ABS/ESC speed sensor in various Audi vehicles from model years 2022-2026. This bulletin, which supersedes Group 45 number 23-36 dated December 13, 2023, provides guidance for technicians on diagnosing and resolving this specific condition. Owners experiencing an Audi ABS/ESC implausible signal should be aware of the potential causes and recommended service procedures.

Symptoms

Owners of affected Audi vehicles may observe specific warning messages appearing in the instrument cluster. These include:

• "TPMS warning appears in the instrument cluster although there is no pressure loss."
• "ABS/ESC warning message appears in the instrument cluster."

These warnings indicate that the vehicle's systems are detecting an anomaly related to wheel speed, even if there is no actual tire pressure issue or immediate loss of stability control.

Fault Codes / DTCs

During workshop diagnosis, technicians may find a Diagnostic Trouble Code (DTC) stored in the ABS control unit J104 (address word 0003). This DTC will specifically refer to an "implausible signal of a rotational speed sender." It's possible for multiple rotational speed senders to report implausible signals simultaneously.

Diagnosis / Trigger Conditions

The root cause for an Audi ABS/ESC implausible signal typically stems from external factors affecting the ABS speed sensor or the sensor ring on the wheel bearing. If dirt, foreign objects, or grease accumulate in this area, they can distort the signals transmitted by the ABS speed sensor. This distortion leads the ABS control unit J104 to interpret the signal as implausible, triggering the warning messages.

Repair Procedure Summary

To resolve the implausible signal issue described in TSB 45 24 46 2072304/2, technicians are instructed to perform a thorough inspection and cleaning process. The primary steps involve:

1. Inspection: Carefully check the ABS speed sensors and the sensor rings located on the wheel bearing for any foreign objects, excessive grease, or dirt accumulation.
2. Cleaning: Clean all dirty components meticulously to ensure clear signal transmission.
3. DTC Erasing: After cleaning, erase any stored DTCs from the system.
4. Further Diagnosis: If, after cleaning and checking, no irregularities are detected, and the issue persists, technicians should proceed with Guided Fault Finding to further diagnose any underlying problems.

Important Warnings

Audi Technical Service Bulletin 45 24 46 2072304/2 is provided for informational purposes only and is not applicable to any Audi Warranty. Owners should be aware that this service action may not be covered under standard warranty terms.

Source: NHTSA ID: 11009348, TSB ID: 45 24 46 2072304/2