Patent ID: 8839665
Filing Date: 2014-09-23
Classification: G01M

Abstract:
1. A vehicle comprising: an internal combustion engine; a radiator; a coolant that cools the internal combustion engine; a sensor that detects a temperature of the coolant; an electric water pump that circulates the coolant through an interior of the internal combustion engine through a first passage or a second passage, the first passage circulates the coolant without passing through the radiator, and the second passage circulates the coolant through the radiator; a thermostat that switches the circulation of the coolant from the first passage to the second passage as the temperature of the coolant rises; and an electronic control unit that determines a malfunction of the thermostat based on the detected coolant temperature; wherein the electric water pump starts circulation of the coolant after a first predetermined time after the internal combustion engine is started, and the electronic control unit determines the malfunction of the thermostat when a second predetermined time has elapsed after the electric water pump starts circulation of the coolant, the second predetermined time is longer than a time for determining the malfunction of the thermostat when the internal combustion engine is started and the electric water pump is operated at the same time.