Apparatus, vehicle, and method for determining a thermostat malfunction in an engine cooling system

摘要

A malfunction determination apparatus for a cooling apparatus that cools an internal combustion engine by circulating a coolant through an interior of the internal combustion engine, using an electric pump, after the internal combustion engine is started includes: a detection portion that detects the coolant temperature; and a determination portion that determines a malfunction has occurred in a thermostat, if a state in which the detected coolant temperature remains below a first threshold temperature after the electric pump begins operating, following start of the internal combustion engine, continues for at least a pre-determined time. The thermostat is a thermostat for switching from a first passage for circulating the coolant without passage via an interior of a radiator of the cooling apparatus to a second passage for circulating the coolant via the interior of the radiator, as the coolant temperature rises.

主权项

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.