2024 Audi Electrical Warning DTC U046900 B200096

Owners of various 2024 Audi models may encounter a yellow or red "Electrical Supply warning" message displayed in the instrument cluster. This warning is often accompanied by the more urgent message, "Electrical system: malfunction! Safely stop vehicle." This condition is addressed by Audi Technical Service Bulletin (TSB) 2072960/2, which supersedes an earlier bulletin (Group 27 number 24-66 dated February 9, 2024).

This TSB primarily concerns diagnostic trouble codes (DTCs) related to the Battery Starter Generator and other electrical system components. Audi is currently gathering information on these fault codes to better understand the underlying causes and develop appropriate solutions for the Audi electrical warning U046900 and related issues.

Symptoms

Owners will typically notice a prominent warning message in their vehicle's instrument cluster. The primary symptom is a yellow or red "Electrical Supply warning." This can escalate to a more critical message stating, "Electrical system: malfunction! Safely stop vehicle." These warnings indicate a potential issue with the vehicle's electrical system, specifically involving the Battery Starter Generator.

Fault Codes / DTCs

When these symptoms occur, one or more of the following diagnostic trouble codes (DTCs) may be stored in the Engine Electronics control unit (address word 0001) or the Starter Generator control unit (address word 00CC):

Note that DTC U046900 may be associated with symptoms identified as 36564, 34763, or 26950. These codes help technicians pinpoint the specific area of concern within the electrical system.

Important Warnings

Audi explicitly states that technicians should not replace any parts before contacting the Audi Technical Assistance Center (TAC). This directive is crucial because TSB 2072960/2 is primarily an information-gathering effort. Its purpose is to assist Audi in thoroughly diagnosing potential issues related to the electrical warning and associated DTCs, such as the Audi electrical warning U046900.

Replacing components prematurely will not resolve the underlying issue and may lead to unnecessary costs and wasted effort. This Technical Service Bulletin is informational only and is not applicable to any Audi Warranty claims. Furthermore, no changes to vehicle production have been made, as Audi has not yet identified a specific production issue or a definitive repair solution.

Service Procedure Summary

Audi is requesting cooperation from technicians to gather comprehensive technical information regarding this condition. The general procedure for addressing the "Electrical system: malfunction! Safely stop vehicle" warning and related DTCs involves several key steps:

1. Verify and Document: Technicians must first confirm the presence of the electrical warning and document it thoroughly. This includes taking clear images of the instrument cluster display showing the warning message, such as "Electrical system: malfunction! Safely stop vehicle." Accurate documentation is vital for Audi's diagnostic efforts.
2. Identify Hardware: The hardware part number in diagnostic address CC needs to be identified. Technicians should specifically look for part numbers 4N1.903.028, 4N1.903.028.B, or 4N0.903.028.S. This helps determine if the vehicle has a specific component version that might be contributing to the issue.
3. Contact TAC: If the vehicle is still within its New Vehicle Limited Warranty period, the technician must contact an Audi Technical Assistance Center (TAC) consultant. When contacting TAC, they are required to attach the stored DTCs, the diagnostic log with test plan faults performed, and the picture of the warning displayed in the cluster. This ensures that Audi's engineering teams receive all necessary data to investigate the root cause of the electrical system malfunction.

This meticulous process is designed to help Audi understand the nature of the problem and eventually develop a definitive repair for the Audi electrical warning U046900 and other related fault codes.

Source: NHTSA ID: 10251499