2023-2024 Audi A5, S5, RS 5 Emergency Call Fault TSB

Symptoms of the Audi A5 Emergency Call Fault

Owners of 2023-2024 Audi A5, S5, and RS 5 models may experience issues with their emergency call system and microphone functionality. The primary indication of this problem is a specific message displayed on the instrument cluster.

The instrument cluster will show the warning: "Emergency call function: fault. Function unavailable. Please contact workshop". In addition to this message, drivers might notice that they cannot be heard by the person on the other end of the line during a phone call, indicating a microphone malfunction. This condition directly relates to the Audi A5 emergency call fault.

Fault Codes (DTCs)

When diagnosing the Audi A5 emergency call fault, technicians may find specific Diagnostic Trouble Codes (DTCs) stored in various control modules. These codes pinpoint the exact nature of the microphone or communication issue.

Code	Description	Module
B129B13	Microphone 1, open circuit	Control module for Emergency Call Module and Communication Unit -J949-
B129C13	Microphone 2, open circuit	Control module for Emergency Call Module and Communication Unit -J949-
U10B500	Microphone control module, no communication	Data Bus On-Board Diagnostic Interface -J533-

These DTCs indicate problems with the microphone circuits or a lack of communication from the microphone control module -J886-.

Diagnosis and Trigger Conditions

The underlying cause for the Audi A5 emergency call fault is identified as a hardware issue within a specific production batch of microphone control modules. Technicians may find that they cannot establish a connection with the microphone control unit -J886- (diagnostic address 00A6) using the ODIS tester, which further confirms the module's malfunction. This TSB, 2074928/1, applies when these customer complaints and DTCs are present.

Repair Procedure Summary

To resolve the emergency call fault and microphone issues, the recommended repair involves replacing the faulty microphone control unit. This procedure is outlined in Technical Service Bulletin 2074928/1. The repair focuses on the microphone control module -J886-, which is located at diagnostic address 00A6. Once the new module is installed, the system should regain full functionality, clearing the "Emergency call function: fault" message and restoring microphone operation.

Required Parts

The primary component required for this repair is the microphone control module. Owners or technicians should ensure they obtain the correct part number.

• Microphone Control Module: Part number 420.907.394.B
• Fasteners, Bolts, Nuts, and Screws: As needed per the repair manual (refer to ETKA/ELSA for specific quantities and types).

Always consult with your Audi Parts Department and/or ETKA for the latest information and any updated part numbers or bulletins.

Important Warnings

Owners should be aware that all warranty claims related to this issue must adhere to the Audi Warranty Policies and Procedures Manual. Claims are subject to review or audit by Audi Warranty. Additionally, all part and service references provided in this Technical Service Bulletin 2074928/1 are subject to change or removal, so it is always best to verify information with an authorized Audi service center.

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Source: NHTSA ID: 11007344, Audi Technical Service Bulletin 2074928/1