2023-2024 Audi A5 Emergency Call Fault TSB 2074928/1

Symptoms of an Emergency Call System Fault

Owners of 2023-2024 Audi A5, A5 Cabriolet, A5 Sportback, S5, S5 Cabriolet, S5 Sportback, RS 5, and RS 5 Sportback vehicles may experience an Audi A5 emergency call fault. The primary indicators of this issue include a specific message displayed on the instrument cluster and problems with phone call audio.

Customers will see the message: "Emergency call function: fault. Function unavailable. Please contact workshop". Additionally, during a phone call, the customer may find that they cannot be heard by the person on the other end of the line.

Fault Codes / DTCs

When diagnosing the Audi A5 emergency call fault, technicians may find several Diagnostic Trouble Codes (DTCs) stored in various control modules. These codes point to issues with the microphone system and communication.

Code	Description	Control Module
B129B13	Microphone 1, open circuit	Emergency Call Module and Communication Unit -J949- (0075)
B129C13	Microphone 2, open circuit	Emergency Call Module and Communication Unit -J949- (0075)
U10B500	Microphone control module, no communication	Data Bus On-Board Diagnostic Interface -J533- (0019)

These DTCs, particularly U10B500, indicate a communication problem with the Microphone control module -J886- (address word 00A6).

Diagnosis and Trigger Conditions

This TSB, identified as 91 24 42 2074928/1, applies if the customer complaints described above can be reproduced and the listed DTCs are stored in the respective control units. The underlying cause for this Audi A5 emergency call fault is a hardware issue within a specific production batch of microphone control units.

Repair Procedure Summary

To resolve the Audi A5 emergency call fault, the microphone control unit (diagnostic address 00A6) must be replaced. This procedure involves removing the existing faulty unit and installing a new one. The TSB specifies that this is a hardware-related problem and no production changes are planned as the end of production for the affected component is in Q4/2024.

Required Parts

To perform this repair, the following main part is required:

• 420.907.394.B Microphone Control Module (Quantity: 01)

Additionally, fasteners, bolts, nuts, and screws may be needed as per the repair manual. Always check with your Audi Parts Department and/or ETKA for the latest information and parts bulletins regarding these components.

Important Notes for Owners

Audi advises that all part and service references provided in TSB 2074928/1 are subject to change and/or removal. It is crucial to always check with your Parts Department and/or ETKA for the most current information and any relevant parts bulletins. Furthermore, the Repair Manual should be consulted for details on fasteners, bolts, nuts, and screws that require replacement during the repair process.

Warranty Information

This repair is covered under warranty using the following codes:

• Service Number: 9157
• Damage Code: 0040
• Labor Operations: Remove and install microphone control unit (9157 1951)
• Diagnostic Time: GFF (0150 0060), as stated on the diagnostic protocol.
• Claim Comment: As per TSB 2074928/1

All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual and are subject to review or audit by Audi Warranty.

NHTSA ID: 11007263