| 摘要 |
PROBLEM TO BE SOLVED: To provide a cooling device for an internal combustion engine capable of improving detection precision for abnormality of a thermostat. SOLUTION: This cooling device is provided with the thermostat 61 for adjusting amount of supply of cooling water 31 to a radiator 63, a reference temperature inferring means for inferring a simulation value of temperature of cooling water based on at least vehicle speed, and a diagnosing means for diagnosing an operation condition of the thermostat 61 based on comparison of a value detected by a cooling water temperature sensor with the simulation value of temperature of cooling water when diagnosis conditions are satisfied. The cooling device inhibits diagnosis of an operation condition of the thermostat 61 when time of a slope going-down running condition of a vehicle is used as slope going-down running time and a ratio of the slope going-down running time to time from start of the internal combustion engine to the time when the diagnosis conditions are satisfied is above a determined value. COPYRIGHT: (C)2007,JPO&INPIT
|
