2021-2022 Audi e-tron Battery Module Software Update

Audi has issued Technical Service Bulletin (TSB) 93N6 to address a software update for the Battery Modules Control Unit (NVLW) in certain 2021-2022 Audi e-tron vehicles. This proactive update aims to prevent conditions that could affect the long-term health and performance of the high-voltage battery system.

Symptoms

The battery system in electric vehicles, such as the Audi e-tron, relies on numerous individual battery cells. These cells naturally have slight variations in capacity and voltage. Without proper balancing, the overall battery capacity can be limited by the weakest cell, and individual cells may experience premature overloading and aging. The original software might have an error in cell voltage measurement, which could impact the efficiency of the battery balancing function. While there may not be immediate owner-perceptible symptoms, this Audi e-tron battery module software update is crucial for maintaining optimal battery performance and longevity.

Important Warnings for Owners and Technicians

This TSB includes several critical warnings to ensure the update is performed correctly and safely, and to protect owners from potential issues:

• Radiator Fan Operation: "Radiator Fan(s) may cycle ON high speed during the Update Process!" There is a serious risk of personal injury if contact is made with spinning fan blades. Keep hands and all objects away from the radiator fan(s) during the update process.
• Wireless Connection Prohibited: "Using Bluetooth or WiFi for this action is PROHIBITED!" Performing the software update via Bluetooth or Wi-Fi significantly increases the risk of losing connection, which could damage the control module and lead to non-payment of warranty claims.
• Guided Fault Finding (GFF) Warning: "Do NOT USE Guided Fault Finding (GFF) to perform this flash." Using GFF will prolong the flash process, and requests for additional time will not be considered.
• Battery Voltage: "Control modules damaged by insufficient voltage will not be covered." The vehicle battery must maintain above 12.5 volts throughout the update, requiring a connected battery charger.
• Warranty Status: "If this UPDATE appears to have already been performed but the code still shows open in Elsa, contact Warranty before proceeding further." This prevents duplicate work and ensures proper claim processing.
• Safety Recalls First: "All Safety Recalls must be completed prior to completing this campaign." This ensures all critical safety issues are resolved before proceeding with this update.

Repair Procedure Summary

The Audi e-tron battery module software update involves a specific procedure using specialized diagnostic equipment. Technicians must ensure several prerequisites are met before starting the update:

1. Software and Tool Preparation: The ODIS software on the VAS Diagnostic Tester must be completely up to date. The diagnostic tester must be plugged in using its supplied power adapters, not relying on battery power. Screen saver and power-saving settings must be disabled on the tester.
2. Vehicle Preparation: The vehicle's battery charger (e.g., GRX3000VAS Tester/Charger) must be connected to the vehicle battery in POWER SUPPLY MODE to maintain voltage above 12.5 volts throughout the process. Hazard warning lights must be switched on to prevent the system from entering bus sleep mode.
3. Diagnostic Connection: The VAS Diagnostics Interface must be connected to the tester using a USB cable, not Bluetooth or Wi-Fi.
4. Initiating the Update: The technician will enter the VIN into the Elsa system to verify eligibility for the 93N6 update. After confirming the campaign status is