ENGINE COOLANT CIRCULATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an engine coolant circulation system capable of taking an appropriate measure against an abnormality when the abnormality causing control failure of a flow control valve occurs.SOLUTION: An engine coolant circulation system includes: a block path 20 for cooling a block portion of an engine by making a coolant flow in the block portion; a head path 30 for cooling a head portion of the engine by making the coolant flow in the head portion; valves Vb1, Vh1 for controlling a flow rate of each of the coolants flowing in the block path 20 and the head path 30 in accordance with change of a flow passage area by using a valve element 41; and an ECU 70 for controlling openings of the valves Vb1, Vh1 within a predetermined opening range. The valves Vb1, Vh1 are configured so that a minimum opening thereof on the block path 20 side in a state where the opening control by the ECU 70 is not permitted becomes zero and a minimum opening on the head path 30 side in the same state becomes a predetermined opening larger than zero.