| 摘要 |
PURPOSE:To decide the abnormal condition of an EGR(exhaust gas recirculating) device without confounding with the other abnormality of the engine. CONSTITUTION:An ECU31 reads the throttle opening TA, the suction air amount Q, the engine rotation frequency NE, the cooling water temperature THW, and the like, depending on the detecting signals from sensors 15 to 18, 25, 26, and 30, and a status switch 29. And the CPU 31 decides whether it is in the EGR operating area or not from these read data, and calculates the basic ignition timings theta B1 and thetaB2 according to the deciding result. And the ECU 31 calculates log angle amounts thetaK1 and thetaK2 according to whether it is in the EGR operating area or not depending on the knock detecting signal from a knock sensor 27, in a KCS operating area. The ECU 31 decides an abnormal condition of an EGR device 20 from the difference of the log angle amounts thetaK1 and thetaK2 (= thetaK1-thetak2). Consequently, knocking generating causes other than the EGR device 20 are cancelled, and only the abnormal condition of the EGR device 20 is decided accurately. |
