A vehicle includes: a radiator that cools cooling water; a grille shutter that is provided on a vehicle front side of the radiator and opens or closes a grille provided in a vehicle; a first flow path in which the cooling water passes through the radiator; a second flow path in which the cooling water does not pass through the radiator; a thermostat that switches a path between the first flow path and the second flow path; and a failure determiner that performs failure determination of the thermostat based on an actual temperature of the cooling water and an estimated temperature of the cooling water, the estimated temperature being calculated based on a temperature change of the cooling water caused by an open or close state of the grille shutter.