A protective redundancy circuit is provided for a power tool having an electric motor. An embodiment of the hydraulic system comprises a reservoir for hydraulic fluid; a load sensitive variable displacement pump for pumping hydraulic fluid from the reservoir; and a plow onoff valve having a pressure port coupled to the pump for receiving hydraulic fluid under pressure. The controller includes a processing circuit responsive to executable instructions for producing the steering assistance to the steering device to reduce a difference between the predicted path and the target path, thereby serving to maintain lane centering of the vehicle.