To provide a technology of identifying a ground wire susceptible to overheating.

A hybrid vehicle 2 includes: a PCU 10 which is connected to a body 100 via a plurality of wiring harnesses 21, 23 28; temperature sensors 31, 33 and 35 which detect ambient temperatures of the plurality of wiring harnesses 21, respectively; and a controller 12 which detects the overheating of the wiring harnesses 21, 23 28. The controller 12 determines a resistance value of the wiring harness 21 and the like from a relationship between a prestored ambient temperature and the resistance value, and the ambient temperatures detected by the temperature sensor 31 and the like, determines a value of an electric current flowing through the wiring harness 21 and the like from the resistance value and an output current of the PCU 10, determines a temperature rising part caused by the generation of heat from the wire harness 21 and the like from the current value and the resistance value, and outputs data indicating that the sum of the temperature rising part and the ambient temperature exceeds a heat-resistant temperature prestored by the controller 12 when the sum exceeds the heat-resistant temperature.