| 摘要 |
Upon a valve rotation angle of a flow rate control valve (15) exceeding a radiator-flow-path closed position during changing of the valve rotation angle of the flow rate control valve (15) in an opening direction of a radiator flow path (16) from a closed state of the radiator flow path (16), a cooling water starts to circulate through the radiator flow path (16), and an outlet water temperature or an inlet water temperature of an engine (11) starts to drop. The radiator-flow-path closed position is learned as a valve rotation angle of the flow rate control valve (15) immediately before the outlet water temperature detected by an outlet water temperature sensor (22) or the inlet water temperature detected by an inlet water temperature sensor (23) starts to drop during changing of the valve rotation angle of the flow rate control valve (15) in the opening direction of the radiator flow path (16) from the closed state of the radiator flow path (16). Consequently, a malfunction caused by a variation in the radiator-flow-path closed position of the flow rate control valve (15) regulating a cooling-water flow rate in the radiator flow path can be restricted. |
