Patent ID: 6615647
Filing Date: 2003-09-09
Classification: F01P,F02D,Y02T

Abstract:
A failure detection apparatus for a cooling system of an internal combustion engine, said cooling system having a radiator, a cooling water pipe for circulating a cooling water in said engine to said radiator, and a thermostat provided in said cooling water pipe for opening and closing said cooling water pipe, said failure detection apparatus detecting failure of said thermostat and comprising:vehicle speed detecting means for detecting a vehicle speed of a vehicle driven by said engine; operating condition detecting means for detecting an operating condition of said engine, said operating condition detecting means including cooling water temperature detecting means for detecting a temperature of the cooling water; estimated cooling water temperature calculating means for calculating an estimated cooling water temperature of said engine according to said operating condition detected by said operating condition detecting means; and determining means for comparing said estimated cooling water temperature and a determination threshold set according to said vehicle speed at the time said cooling water temperature detected by said cooling water temperature detecting means has exceeded a predetermined water temperature, to thereby determine that said thermostat is normal.