2021-2024 Audi Q5 e / A7 e Red Electrical System Fault P0AC000

Audi has issued Technical Service Bulletin (TSB) 2074901/1 to address a specific electrical system fault affecting certain 2021-2024 Audi Q5 e quattro and A7 e quattro plug-in hybrid electric vehicles (PHEVs). This TSB details a condition where a red electrical system warning appears in the instrument cluster, often preventing the vehicle from starting. Owners searching for a solution to an Audi Q5 e P0AC000 fault will find this information relevant.

This bulletin, dated August 27, 2024, provides guidance for diagnosing the issue and emphasizes that a permanent fix is still under development. It is crucial for owners and technicians to understand the interim recommendations provided by Audi.

Symptoms

Owners of affected Audi Q5 e quattro and A7 e quattro models may experience the following symptoms:

• A red electrical system warning light illuminates in the instrument cluster.
• The instrument cluster displays the message: "electrical system fault. Safely stop vehicle".
• The vehicle may be unable to start.

Fault Codes / DTCs

When diagnosing this issue, technicians will typically find the following Diagnostic Trouble Code (DTC) stored in the hybrid battery management module, J840 (address word 008C):

This DTC can be active or passive, indicating either a current or historical fault with the hybrid battery pack current sensor circuit.

Diagnosis

The TSB specifies that the switching unit for the high-voltage battery, identified as SX6, may have a software version of 0108 or 0208. Technicians can verify the software version of the SX6 unit by following a specific procedure within the ODIS diagnostic system. This involves navigating through Guided Functions to diagnostic address 008C, then selecting