Patent ID: 8479569

Claim:
A malfunction determination apparatus for a cooling apparatus that cools an internal combustion engine by circulating a cooling medium that flows in a first passage that extends through an inside of the internal combustion engine, using an electric pump, wherein the cooling apparatus includes a radiator, a second passage for circulating the cooling medium to the first passage so that the cooling medium bypasses the radiator, a third passage for circulating the cooling medium to the first passage via the radiator, and a switching valve that switches a flow passage for the cooling medium from a flow passage including the second passage to a flow passage including the third passage, in response to an increase in a temperature of the cooling medium after the internal combustion engine is started, the malfunction determination apparatus comprising: an inlet temperature detection portion that detects a first temperature of the cooling medium at an inlet of the first passage, through which the cooling medium flows into the inside of the internal combustion engine; an outlet temperature detection portion that detects a second temperature of the cooling medium at an outlet of the first passage, through which the cooling medium flows out from the inside of the internal combustion engine; and a normal function determination portion that determines that the switching valve is able to normally select the second passage, if both of the first temperature and the second temperature reach a first threshold value when the temperature of the cooling medium increases due to start of the internal combustion engine.