| 摘要 |
PROBLEM TO BE SOLVED: To provide an abnormality detecting device for an exhaust gas circulation device to improve precision of abnormality detection as an opportunity to detect abnormality of an exhaust gas re-circulating device is ensured. SOLUTION: Detection of abnormality of an EGR mechanism is carried out based on a reduction amountΔP of an intake pressure PM when an EGR valve 43 is closed to a target EGR opening Et for detecting abnormality. When the EGR valve 43 is closed to the target opening Et for detecting abnormality of the EGR valve 43, the opening of a stop valve 23 is fixed. Thereby, a fluctuation of the intake pressure PM occasioned by a change of throttle opening is suppressed, erroneous detection of the abnormality due to the fluctuation is prevented from occurring. Further, since a fluctuation of the intake pressure PM is suppressed, the execution of detection of abnormality of the EGR mechanism is practicable even when the operation state of an engine 11 is not in a stable state.
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