Engine cooling fan diagnosis device

摘要

A vehicle engine temperature is detected, and a radiator fan fault warning is given so as to prevent engine overheating when this temperature rises to or above a preset determining value under a predetermined test conditions. Preferably, it is determined that the radiator fan has a fault when a temperature equal to or above this determining value holds for at least a predetermined time. More preferably, this determining value is set low while the vehicle is in motion. By providing these supplementary conditions, incorrect diagnosis of a fault in the radiator fan is prevented.