Perform High Voltage Battery Cell Balancing

Tools Required: Tesla-approved Level 2 or Level 3 charging equipment, Tesla Toolbox 3 software, and a stable power source.

Safety Precautions: Ensure all high-voltage safety protocols are followed. Do not attempt to open the battery pack enclosure. Verify the vehicle is parked on a level surface in a well-ventilated area.

Steps:

1. Connect the vehicle to a high-voltage charger.
2. Initiate a full charge cycle to 100% capacity.
3. Maintain the connection to the charger for at least 2 to 4 hours after the charge cycle reaches 100% to allow the Battery Management System (BMS) to perform passive cell balancing.
4. Use the Tesla Toolbox 'BMS_Cell_Balance_Check' routine to confirm that the voltage delta between cells has returned to within the acceptable factory specification.

Verification: The fix is successful if the BMS reports a cell voltage delta below the specified threshold and the SOC percentage accurately reflects the total pack voltage without premature low-power alerts.

Sources