Motor-driven power steering system for a vehicle

摘要

A motor-driven power steering system for a vehicle capable of changing into a non-power assisted manual steering mode by means of a control unit when a speed sensor detects that the vehicle speed has exceeded a prescribed level. When the speed sensor has failed and/or wiring connecting the speed sensor to the control unit is broken, the control unit detects such sensor failure or wiring breaks and operates to change the steering system into a non-power assisted manual steering mode, thereby improving safety in high-speed driving of the vehicle.