2022-2025 Audi Emergency Call Fault U178500 TSB

Symptoms

Owners of affected 2022-2025 Audi A3, S3, RS3, and Q3 vehicles may observe a specific warning message displayed on the instrument cluster. This message indicates a malfunction with the vehicle's emergency call system. The exact message owners will see is: "Emergency call function: fault. Function unavailable. Please contact workshop."

This warning indicates that the vehicle's ability to automatically contact emergency services in the event of a crash, or for the driver to manually initiate an emergency call, may be compromised. The fault is often described as passive or sporadic, meaning it may appear intermittently rather than constantly.

Fault Codes / DTCs

When diagnosing an Audi emergency call fault U178500, technicians will find a specific diagnostic trouble code (DTC) logged in the vehicle's Control Module for Emergency Call and Communication Unit (OCU) -J949-. This module is identified by diagnostic address 0075.

Code	Description	Module	Storage State
U178500	Control module for emergency call module and communication unit Software error	0075 - Emergency call module and communication unit	Intermittent

Diagnosis / Trigger Conditions

The Audi emergency call fault U178500 is triggered by a software error within the emergency call module and communication unit, also known as J949. This issue affects the functionality of the vehicle's telematics and online services, leading to the displayed malfunction message. The fault is typically identified by scanning the vehicle's control units for stored DTCs, specifically looking for U178500 in the 0075 - Emergency call module and communication unit.

Important Warnings for Owners and Technicians

Audi Technical Service Bulletin 2073131/4 includes critical information regarding the repair process and the nature of this particular fault:

• Replacing the emergency call module control unit and communication unit J949 does not fix the problem. This is a crucial point, as attempting to replace the hardware will not resolve the underlying software issue and will incur unnecessary costs and labor.
• The complaint may re-occur. If the complaint occurs again, please repeat the procedure above. This indicates that the current service procedure is a temporary measure. Owners should be aware that the "Emergency call function: fault" message might reappear even after the recommended steps are performed.

Repair Procedure Summary

For vehicles experiencing the Audi emergency call fault U178500, the current service procedure outlined in TSB 2073131/4 involves a diagnostic and configuration routine. Technicians are instructed to perform the suggested ODIS routine: "0075 "0075 - Check control module configuration" configuration". Following this, the emergency call LED should be checked to ensure it is green, indicating proper function. As noted, simply replacing the emergency call module (J949) will not resolve the software error.

Audi is actively developing a permanent software update to address this issue. For 2021-2023 model years, a software package (Cluster 37 service package 2) is being developed to fix several complaints, as detailed in TSB 2076404. Similarly, for 2024-2025 model years, a different software package (Cluster 3B+ customer service package) is under development, with deployment information found in TSB 2079416. These future updates aim to permanently rectify the software error in the emergency call module.

Required Tools or Parts

The primary tool required for addressing the Audi emergency call fault U178500 is the ODIS (Offboard Diagnostic Information System) diagnostic system. This system is used to perform the specified control module configuration routine. No specific replacement parts are required for the temporary fix, as replacing the emergency call module itself will not resolve the software issue.

Control Unit Software Information

The emergency call module and communication unit (0075) can be identified by various software part numbers and corresponding software versions. These details are crucial for technicians to ensure the correct software is being addressed or updated. The TSB lists the following control unit software information:

Diagnostic address	Software part number	Software version
0075 - Emergency call module and communication unit	5WA.035.285.C	0322
0075 - Emergency call module and communication unit	8Y0.035.282.D*	0144
0075 - Emergency call module and communication unit	5WA.035.284.G*	0143
0075 - Emergency call module and communication unit	8Y0.035.283.A	0021

Warranty Information

This Technical Service Bulletin (TSB 2073131/4) outlines the warranty claim process for addressing the Audi emergency call fault U178500. The Service Number for this procedure is 9170, and the Damage Code is 0039. Labor Operations GFF (0150 0060 and 0150 0010) are specified for the diagnostic and configuration work. The claim comment should reference TSB 2073131/3. All warranty claims must adhere to the Audi Warranty Policies and Procedures Manual. It is important to note that if the vehicle is outside of its warranty period, this TSB serves as informational guidance only, and the repair may not be covered free of charge.

What Owners Should Know

While a temporary fix is available, Audi is working on a permanent software solution for the Audi emergency call fault U178500. Owners of 2022-2025 Audi A3, S3, RS3, or Q3 models should be aware that the current procedure may not prevent the fault from re-occurring. If the "Emergency call function: fault" message reappears, the service procedure should be repeated. It is crucial not to replace the emergency call module hardware, as this will not resolve the underlying software issue. Audi plans to release the permanent software updates for these vehicles by September 26, 2025.

NHTSA ID: 11023759