2021-2022 Audi A7/Q5 P0A9500 Yellow Warning Lamp TSB

Symptoms

Owners of 2021-2022 Audi A7 and Q5 Plug-in Hybrid Electric Vehicles (PHEV) may experience specific issues related to the electrical system. These include:

• The message "Electrical system: fault. Please contact workshop" appearing on the instrument cluster, accompanied by a yellow warning lamp.
• The vehicle may fail to start.

Fault Codes / DTCs

When these symptoms occur, a specific Diagnostic Trouble Code (DTC) may be intermittently stored in the hybrid battery regulation control module, identified as J840 (address word 008C).

Important Warnings for Owners

Audi Technical Service Bulletin PSS 93 (2062953/1) provides critical guidance for this condition:

• Do not replace components: "Do not replace any components for this condition since this will not resolve the customer's concern." The bulletin explicitly states that replacing parts like the switching unit for the high-voltage battery will not fix the underlying problem, despite what Guided Fault Finding might suggest.
• Warning lamp behavior: "Please inform the customer that the warning lamp described above will go out if the vehicle is switched off for at least five seconds."

Technical Background

This intermittent "Electrical system: fault" warning and the associated DTC P0A9500 are not due to a physical component failure. Instead, the issue stems from an irregularity in the diagnostic system. This irregularity can cause the DTC to be logged without an actual fault, particularly during dynamic cornering maneuvers.

Repair Procedure Summary

As of the bulletin date, a permanent software solution is currently under development by Audi. This new software is designed to rectify the diagnostic irregularity that causes the intermittent DTC P0A9500 and the related warning messages. Until the software is released, no physical repairs are necessary or recommended.

Owners experiencing the "Audi A7 P0A9500 yellow warning" should be informed that a solution is forthcoming in the first quarter of 2022. Dealerships are instructed not to perform any repairs or replace components for this condition, as it will not resolve the issue. Instead, a PSS (Pending Service Solutions) record should be created in the AccessAudi system.

Warranty Information

This condition is covered under Audi's warranty policies. For eligible vehicles, claims can be submitted under claim type 110 for up to 48 months or 50,000 miles. Certified Pre-Owned (CPO) vehicles are covered under claim type G10, requiring owner verification. If the vehicle is outside of any applicable warranty, this Technical Service Bulletin serves as informational guidance only.

Warranty claims must adhere to the Audi Warranty Policies and Procedures Manual. The diagnostic time for Guided Fault Finding (GFF) is 0150 0000, with a maximum of 20 Technical Units (TU). There is no allowance for road tests before or after the service procedure.

NHTSA ID: 10190518