ABNORMALITY DIAGNOSIS DEVICE FOR EXHAUST GAS RECIRCULATION DEVICE

摘要

An abnormality diagnosis device for an exhaust gas recirculation device for an internal combustion engine. The exhaust gas recirculation device has an exhaust gas recirculation valve for adjusting the amount of recirculation of exhaust gas returned from the exhaust path to the intake path of the engine. The abnormality diagnosis device has a control section for changing the opening degree of the exhaust gas recirculation valve in order to diagnose abnormality of the exhaust gas recirculation device. When abnormality diagnosis execution conditions are established, the control section prohibits, prior to execution of valve closing processing, the correction of the opening degree and performs valve opening processing for increasing the opening degree of the exhaust gas recirculation valve from the opening degree at that moment to a second target opening degree greater than a first target opening degree.