METHOD FOR DIAGNOSING OBSTACLE OF THERMOSTAT

摘要

PURPOSE: A failure diagnostic method of a thermostat is provided to indicate troubles to a driver by diagnosing troubles or errors in a specific mode. CONSTITUTION: A failure diagnostic method of a thermostat comprises the next step. A coolant temperature difference value between a radiator and an engine are produced when the first failure diagnosis condition is satisfied after the starting of the engine(S1). The malfunction of a thermostat is determined according that the difference value is over than a preset ordinary value(S5). If it is determined as ordinary operation at a first malfunction diagnosing step, the coolant temperature of the engine reaches a set valve open temperature.