2021-2022 Audi A3/TT/RS3 DTC B116831 ABS Warning

Symptoms

Owners of affected 2021-2022 Audi vehicles may experience several warning lamps, including the ABS and TPMS lights, illuminating sporadically. This typically occurs when the vehicle is started, whether manually or via the start/stop system. This indicates a potential issue that triggers the "Audi DTC B116831 ABS warning".

Fault Codes / DTCs

During diagnosis, technicians may find the following Diagnostic Trouble Code (DTC) stored in the ABS control module, J104 (address word 0003):

Code	Description	Symptom Code
B116831	Steering angle sensor no signal	166

Diagnosis and Trigger Conditions

The root cause for the DTC B116831 and the associated warning lamps is a voltage drop within the power steering control module, J500 (address word 0044). This voltage drop occurs briefly during the vehicle's start procedure, preventing the J500 module from properly communicating on the data bus. The main fuse carrier is often identified as the culprit for this voltage instability.

To diagnose, a technician will measure the voltage at contact 4 on the fuse carrier, which supplies power to the power steering control module J500. If this voltage drops by more than 1 Volt during startup, it confirms the issue with the fuse carrier.

Repair Procedure Summary

Audi Technical Service Bulletin 2063526/1 outlines the steps to address the "Audi DTC B116831 ABS warning". The primary repair involves checking the voltage supply to the power steering control module J500. If a voltage drop exceeding 1 Volt is detected at contact 4 of the fuse carrier, the fuse carrier must be replaced.

Technicians should follow the specific instructions provided in the Elsa Repair Manual for the replacement of the fuse carrier. If replacing the fuse carrier does not resolve the issue, further diagnosis of other power supply components for the power steering system is recommended, including reviewing battery history data to identify any other potential voltage drop sources.

Required Tools or Parts

For this repair, the following parts may be required:

• Fuse carrier: Quantity 01 (Part number to be determined via ETKA)
• Fasteners, Bolts, Nuts, and Screws: As needed, per the Repair Manual (Part numbers to be determined via ETKA/ELSA)

Always consult the latest information in ETKA and with the Parts Department for current part numbers and bulletins.

Warranty Information

This repair, identified under Service Number 9794 and Damage Code 0040, is covered under warranty for up to 48 months or 50,000 miles. For Audi Certified Pre-Owned (CPO) vehicles, the claim type is G10, requiring owner verification. If the vehicle is outside of warranty coverage, this Technical Service Bulletin serves as informational guidance only. Labor operations include checking the current distributor (9794 0199, 20 TU) and replacing the current distributor (9794 5599, 30 TU). Diagnostic time is GFF (0150 0000), with a maximum of 30 TU as stated on the diagnostic protocol.

What Owners Should Do

If your 2021-2022 Audi A3, S3, RS3, TT, TTS, or TTRS is displaying sporadic ABS, TPMS, or other warning lamps upon startup, and you suspect an "Audi DTC B116831 ABS warning", it is recommended to schedule an appointment with an authorized Audi dealership. Provide them with the symptoms you are experiencing. The dealership technicians will be able to diagnose the issue using the guidelines provided in Technical Service Bulletin 2063526/1 and perform the necessary repairs, which may include replacing the fuse carrier.

Source: NHTSA ID 10199929