Customer vehicle is fitted with unauthorized ECM tuning. All systems on Audi vehicles are engineered to work together using the factory calibrations, which have been extensively tested and validated before the vehicle is released for sale. The Audi warranty coverage is based on the results of developing the vehicle under the factory calibration. If a vehicle is equipped with unauthorized hardware or software tuning, it can cause stress on vehicle components outside of intended design limits, and can cause damage and additional wear. Subsequently, factory powertrain warranty coverage is reduced or voided.