FAILUAR DIAGNOSTIC DEVICE FOR THERMOSTAT

摘要

PROBLEM TO BE SOLVED: To quickly and accurately diagnose the failure of a thermostat valve with a simple structure. SOLUTION: This failure diagnostic device is provided with a failure detecting means 13 for detecting at least one of the open failure or the close failure of the thermostat valve 10 for adjusting the cooling water temperature of an engine and a radiation quantity control means 14 for controlling a radiator 2 to increase its radiation quantity by driving a cooling fan 20 when a failure is detected by the failure detecting means 13.