Vehicle speed sensor failure diagnosis device for vehicle and cooling fan motor failure diagnosis device

摘要

PPROBLEM TO BE SOLVED: To provide a vehicle speed sensor failure diagnosis device capable of diagnosing functional failure of a vehicle speed sensor at low cost without providing a plurality of vehicle speed sensors. PSOLUTION: The vehicle speed sensor failure diagnosis device for a vehicle includes the vehicle speed sensor 211 detecting vehicle speed and an electric fan motor 212 cooling refrigerant of an air conditioner and cooling water. The vehicle speed sensor failure diagnosis device is provided with a current detection means 401 detecting current to the electric fan motor, an estimated vehicle speed grasping means 405 grasping estimated vehicle speed based on current value to the electric fan motor 212 detected by the current detection means 401, and a failure judgment means 407 judging a failure of the vehicle speed sensor based on estimated vehicle speed grasped by the estimated vehicle speed grasping means 405 and vehicle speed detected by the vehicle speed sensor 211. PCOPYRIGHT: (C)2008,JPO&INPIT