| 摘要 |
PURPOSE: To stably carry out the judgement of abnormal EGR for controlling adverse effect to emission to the minimum by maintaining an opening-closing means in an EGR passage in a standard state until a steady acceleration state is judged, and when a judgement as the steady acceleration state is attained, first changing over the opening-closing means into an unstandard state. CONSTITUTION: An exhaust gas recirculation system is equipped with a memory means 16 which actuates an opening-closing means 14 in an EGR passage 13, and sets up either of an opened or a closed state as a standard state and the other as an unstandard state, and stores an intake quantity at each detecting time in the standard and the unstandard state on the detecting signal of an intake quantity detecting means 15. When a steady acceleration state is judged (17), the opening-closing means 14 is changed over from the standard state to the unstandard state by an opening-closing control means 18. The intake quantity expected to be obtained in the case where the opening-closing means 14 is kept in the standard state is presumed (19), and the presumed value is compared with the detected value of the intake quantity at the detecting time of the intake quantity in the unstandard state, and whether EGR motion is abnormal or not is thereby judged (20). |
