| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve failure diagnosis accuracy of an electric W/P (electric water pump) provided in an engine cooling system. Ž<P>SOLUTION: This device is provided with: an inlet side water temperature sensor 20 detecting inlet water temperature of an engine 11 (cooling water temperature near a cooling water inlet); and an outlet side water temperature sensor 21 detecting outlet water temperature of the engine 11 (cooling water temperature near a cooling water outlet). Since received heat quantity of cooling water increases in the engine 11 if flow rate of the cooling water drops due to a failure of the electric W/P 12, a difference between inlet water temperature and outlet water temperature of the engine 11 becomes abnormally large. By paying attention to the phenomenon, inlet and outlet water temperature difference which is a difference between outlet water temperature detection value detected by the outlet side water temperature sensor 21 and inlet water temperature detection value detected by the inlet side water temperature sensor 20 is found, and occurrence of a failure in the electric W/P 12 is determined if the inlet and outlet water temperature difference become failure determination value corresponding to a vehicle operation state, or higher. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
