| 摘要 |
PROBLEM TO BE SOLVED: To provide an abnormality determination device for an exhaust gas recirculation system capable of accurately determining occurrence of abnormality causing deterioration of an exhaust gas property. SOLUTION: This device is applied to the EGR system provided with an exhaust gas recirculation (EGR) passage communicating the exhaust passage of an internal combustion engine with the intake passage thereof and an EGR valve installed in the EGR passage. The EGR system executes drive control for the EGR valve such that the target opening Tv of the EGR valve set based on an engine operation area is matched with an actual opening V. It is determined that the EGR system is abnormal, provided (area A) that when the target opening Tv is a decision value Va or higher, the actual opening V is less than a decision value Vb smaller than the decision value Va. It is determined that the EGR system is normal, provided that when the target opening Tv is the decision value Va or higher, the actual opening V is larger than the decision value Vb. COPYRIGHT: (C)2008,JPO&INPIT
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