Consequently, if the vehicle is being driven and there is a loss of power from the main vehicle battery, the transmission cannot be shifted to “Park” and the electric parking brake cannot be applied. If this occurs, the only way to keep the vehicle from moving is for the driver to press the brake pedal. As soon as the driver stops stepping on the pedal by exiting the vehicle, the car could roll, increasing the risk of injury. Mercedes dealers will repair the ignition switch wiring and perform a software update.