2021-2023 Audi e-tron 008C Test Plan Failure Hotfix

Symptoms

Owners of 2021-2023 Audi e-tron vehicles may not directly observe this issue, as it pertains to a diagnostic test performed by technicians. The primary symptom is that the "008C – Determine mean cell voltage function test plan" within the ODIS diagnostic system fails to complete successfully. The test plan ends with the error message: "The vehicle could not be clearly detected". This indicates a communication problem during the diagnostic procedure.

The underlying cause is a communication issue with the battery control unit. While the initial communication works, the PR number on some vehicles prevents the test from proceeding correctly, leading to a loss of connection. This specifically impacts the "mean cell voltage (AX2 - High-Voltage Battery 1 mean cell voltage) test" within the 008C function test plan.

Important Warnings

Audi has issued specific instructions regarding the installation and removal of this hotfix to ensure proper diagnostic functionality:

• "We recommend installation of this hotfix on one diagnostic device ONLY."
• "Hotfix must be removed immediately after performing the procedure."
• "Failure to do so will cause other vehicle diagnostics sessions to malfunction."

These warnings highlight the critical importance of following the procedure precisely to avoid disrupting other diagnostic tasks or tools.

Repair Procedure Summary

To address the failing Audi e-tron 008C test plan, technicians must install a specific hotfix into the ODIS Service diagnostic system. This hotfix, identified as A_2.37.7_PR_NUMBER_20250417-133907, is designed to correct the communication problem that causes the "The vehicle could not be clearly detected" error during the 008C mean cell voltage function test plan.

The procedure involves several key steps:

1. Download the Hotfix: Access AccessAudi.com via a web browser on the diagnostic device. Navigate to Elsa2Go > Service References > Software/Hardware Updates and search for the "AOS-25-21 PR Number Hotfix Zip File". Download and save this file to the desktop.
2. Install Hotfix into ODIS Service: Open ODIS Service (running as Administrator). Expand the 'Data' submenu, click 'Download' under 'Hotfix', and then 'Continue'. The system will prompt to import the workshop data patch. Browse to and select the downloaded hotfix file, then click 'OK' once the patch is successfully imported.
3. Perform Diagnostic Procedure: After the hotfix is installed, the technician can proceed with the intended diagnostic procedure, which includes running the 008C mean cell voltage function test plan.
4. Uninstall Hotfix: Crucially, the hotfix must be removed immediately after the diagnostic procedure is completed. This is done by selecting 'Erase' under 'Hotfix' in the ODIS Service 'Data' submenu, confirming the deletion, and then clicking 'OK'.

This process ensures that the specific diagnostic issue related to the Audi e-tron 008C test plan is resolved without negatively impacting other diagnostic functions.

Required Tools or Parts

To perform this hotfix installation and resolve the Audi e-tron 008C test plan issue, the following are required:

• ODIS Service Diagnostic System: The official Audi diagnostic software, specifically Audi brand version 2.37.7 or newer, is necessary.
• AccessAudi.com Account: A valid account is needed to access and download the hotfix file.
• Hotfix File: The specific hotfix file, A_2.37.7_PR_NUMBER_20250417-133907, must be downloaded.

Owner Action

If you own a 2021-2023 Audi e-tron and your vehicle requires diagnostic work involving the battery control unit or mean cell voltage tests, your Audi service center will be aware of this Service Information AOS-25-21. This issue primarily affects the diagnostic process itself, not the vehicle's operation or a dashboard warning light. There is no direct action required by the owner. If your vehicle is at a dealership for service and they encounter issues with the Audi e-tron 008C test plan, they will apply this hotfix as part of their diagnostic procedure.

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Source: NHTSA ID: 11017668