Patent ID: 8215833

Claim:
A diagnostic apparatus for a vehicle cooling system which mounts a radiator provided with a function of purifying an ambient air passing therethrough, comprising: a front temperature sensor integrally fixed on a front surface of the radiator to detect a temperature of an air flowing into the front surface of the radiator; a rear temperature sensor integrally fixed on a rear surface of the radiator to detect a temperature of an air flowing out from the rear surface of the radiator; and an abnormal diagnosis unit configured to perform an abnormal diagnosis of the radiator based on a relationship between a detection value of the front temperature sensor and a detection value of the rear temperature sensor, wherein when a difference between the detection value of the rear temperature sensor and the detection value of the front temperature sensor is less than or equal to an abnormality determination value, the abnormal diagnosis unit determines that the radiator is altered to an unauthorized radiator having no function of purifying ambient air.