| 摘要 |
PROBLEM TO BE SOLVED: To diagnose abnormality of a control valve accurately, while avoiding the generation of condensed water reliably, upon the achievement of EGR introduction in the early stage at an engine start.SOLUTION: A vehicle includes a cooling system including a control valve that can adjust flow volume of cooling water in a first path and a second path, the first path containing an engine cooling channel and a radiator channel, the second path containing the engine cooling channel and an EGR cooling channel but not containing the radiator channel. In the vehicle, flow of the cooling water to the engine cooling channel is limited at a start of an internal combustion engine, the cooling water starts flowing to the second path when a temperature of the cooling water becomes a reference temperature or higher during a period of the flow limitation, and an EGR gas is introduced after a start of the flow. In the vehicle, an abnormality diagnostic device (100) comprises: identifying means for identifying a temperature of the EGR gas on a downstream side of an EGR cooler; and determining means for determining that the control valve is abnormal when the identified temperature of the EGR gas is determined to be lower than a target temperature. |
