COOLING DEVICE PROBLEM DETECTION DEVICE AND PROBLEM DETECTION METHOD

An ECU executes a program including the steps of: obtaining (S100) a first temperature Ta of a first semiconductor element; obtaining (S102) a second temperature Tb of a third semiconductor element; determining (S110) that it is in a normal state in which clogging has not occurred, when a rotating speed Nm2 of a second MG is more than a threshold value Nm2(0) (YES in S104) and the magnitude of a difference between the first temperature Ta and the second temperature Tb is less than a threshold value T (YES in S106); and determining (S112) that the clogging of a foreign matter has occurred in a predetermined site when the magnitude of the difference between the first temperature Ta and the second temperature Tb is equal to or more than the threshold value T (NO in S106).