A device may determine whether there is a communicated point with open air between a pump and a control valve or on an opposite side to the control valve of the pump, by at least two of pressures: between the pump and the control valve in case the control valve is in a cutoff state, the switching valve is in a communication state, and the pump sends in forward direction, on an opposite side to the control valve of to the pump in case the control valve is in a communication state, the switching valve is in the cutoff state, and the pump sends in reverse direction; and between the pump and the control valve or on the opposite side to the control valve of the pump in case the valves are in the cutoff states and the pump is stopped after one of these cases.