2021 Audi Q5 e / A7 e Electrical System Malfunction TSB

Symptoms

Owners of affected Audi Q5 e and A7 e vehicles may experience a specific set of symptoms related to the electrical system. When the ignition is switched on, a red warning light appears on the instrument cluster, accompanied by the message "Electrical system: Malfunction! Safely turn off vehicle". During this time, the vehicle cannot be moved.

Often, turning the car off and then on again temporarily resolves the issue, allowing the warning light to disappear and the vehicle to operate normally. However, the underlying problem persists and the warning may reappear.

Fault Codes / DTCs

When the "Electrical system: Malfunction! Safely turn off vehicle" warning appears, the hybrid battery management module, J840 (address word 008C), will store the diagnostic trouble code (DTC) P0AC000. This code specifically indicates a "Hybrid/EV Battery Pack Current Sensor 'A' Circuit Range/Performance" issue.

The TSB specifies that the repair applies if P0AC000 is logged as the only entry in 008C, or if it is logged in combination with DTC P33F000 or DTC U059B00. If other DTCs are present in addition to these combinations, standard diagnostic procedures outside of this TSB should be followed.

Technical Background

The root cause of the "Audi Q5 e P0AC000 electrical system malfunction" is an internal communication issue. The Battery Junction Box (BJB – SX6) electronics and the current/voltage sensor are experiencing unusual communication conditions, leading to inaccurate readings. This inaccuracy is what triggers the warning message and the storage of DTC P0AC000.

Initially, Guided Fault Finding might suggest replacing the BJB (SX6), but this TSB clarifies that such a replacement is not effective in resolving the issue. The actual production solution involves an improved software update for the relevant control modules.

Important Warnings

Owners and technicians should be aware of critical steps during the repair process:

• "To prevent the high-voltage battery from charging during the software update, the high-voltage charging cable on vehicles with high-voltage components must be unplugged BEFORE the SVM code is entered. Please note that charging the high-voltage battery during a software update can cause damage to the high-voltage components."
• "If the sequence 'SVM code 1 before SVM code 2' is not followed precisely when flashing or not followed through to the end, it may not be possible to operate the vehicle."

Diagnosis

To determine if your vehicle is affected by this Audi Q5 e P0AC000 electrical system malfunction, a diagnostic scan tool is used. Technicians will access the hybrid battery management module, J840 (address word 008C), and check for the presence of DTC P0AC000, either alone or in combination with P33F000 or U059B00.

Further diagnosis involves identifying the current software and hardware part numbers and versions for both the J840 module and the Battery Junction Box (SX6). This is done by selecting "Guided Functions" in the scan tool, then navigating to the identification data for J840 and its slave modules, including SX6. The collected software and hardware versions are then compared against a table of affected and improved software versions provided in the TSB.

Repair Procedure Summary

The repair for the Audi Q5 e P0AC000 electrical system malfunction involves updating the software in the hybrid battery management module (J840) and/or the Battery Junction Box (SX6). This is performed using the Software Version Management (SVM) system.

Technicians must follow specific instructions outlined in TSB 2011732, "00 Software Version Management (SVM), operating instructions." The update process requires two SVM action codes, 8CA006 and 8CA006KONF, which must be performed in a precise sequence. It is crucial to ensure the diagnostic scan tool is updated to the latest level before beginning the flashing procedure to prevent failures. After both SVM updates are completed, the installed software should match the target improved software versions specified in the TSB.

Required Tools or Parts

To perform this repair, technicians will need a diagnostic scan tool with the latest software updates. No specific replacement parts are required, as the solution is a software update. The process relies on the Software Version Management (SVM) system and its associated action codes.

Warranty Information

This Technical Service Bulletin 93 24 56 2059309/6 outlines warranty coverage for the software update. For new vehicles, the repair is covered under the standard warranty for up to 48 months or 50,000 miles, whichever comes first (Claim Type 110). For Certified Pre-Owned (CPO) vehicles, coverage falls under Claim Type G10, requiring owner verification.

If the vehicle is outside of any applicable warranty, this TSB serves as informational guidance only. Labor operations include software updates (0151 0000) and battery charging (2706 8950), with specific labor time units (TU) allocated for each step. Diagnostic time, including checking and clearing fault codes, is typically included in existing labor operations with no additional allowance.

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Source: NHTSA ID 11002174