ENGINE EXHAUST EMISSION CONTROL DEVICE

摘要

It is judged that a reduction agent supply system located at the downstream of a pump for inlet and pressure feed of a liquid reduction agent in a reduction agent tank is clogged if the pressure of a liquid reduction agent remaining at the downstream of the pump and the upstream of a flow rate control valve is not lowered than a first predetermined pressure until an accumulated injection amount obtained by successively accumulating an injection amount of the liquid reduction agent calculated in real time according to the engine operation state after temporarily stopping the pump reaches a predetermined amount.