| 摘要 |
PROBLEM TO BE SOLVED: To detect abnormity of an exhaust recirculating device in any region, not limited to an idle region, where exhaust recirculation is conducted, and to apply to an exhaust recirculation device which does not recirculate exhaust in the idle region of an internal combustion engine. SOLUTION: An electronic control unit (an ECU) 42 feedback-controls an opening of an EGR valve 34 so as to correspond to an intake air quantity detected by an air flow meter 35 with a target intake air quantity responding to an operation state of a diesel engine 11. When a feedback term of the control is deviated from a predetermined range set more widely than a general range to be covered, the opening of the throttle valve 24 is changed. When the change quantity of the feedback term is not more than a predetermined value even when the opening is changed by a predetermined quantity, it is determined that an EGR device 32 is abnormal. |
