COOLING-WATER CONTROL DEVICE

摘要

Provided is a cooling-water control device (30) for controlling a cooling device (10) provided with: a first passage (181) which passes through an interior of an internal combustion engine (20), and in which a cooling water is made to circulate; a second passage (182) which does not pass through the interior of the internal combustion engine, and in which the cooling water is made to circulate; and a switching valve (13) which switches a state thereof between an open state and a closed stated. The cooling-water control device (30) is provided with: a detection means (30) which detects a first water temperature (thw) of the cooling water in passage sections (181b, 181c) of the first passage which are located between the internal combustion engine and the switching valve; and a determination means (30) which, in cases when a required time period is greater than a prescribed target time period, said required time period being required for the first water temperature to reach a prescribed water temperature after a command instructing that the state of the switching valve be switched from the open state to the closed state has been outputted, determines that a failure has occurred in the switching valve in the closed state.