| 摘要 |
PURPOSE:To suppress the variation of engine torque and suppress the shock given to a driver by carrying out the ignition timing control according to the change of the operation state when the trouble of an EGR control device is diagnosed through the ON/OFF of an EGR. CONSTITUTION:An electronic control unit 22 receives each signal of a pressure sensor 6, crank angle sensor 24, water temperature sensor 17 and a throttle opening degree sensor 8, and under a prescribed condition, the trouble of an EGR control device is diagnosed by turning ON/OFF a solenoid 12 for controlling an EGR recirculation valve. It is judged if the variation of the intake manifold pressure is zero or not, from the signal of the pressure sensor 6 which is inputted according to the ON/OFF of the solenoid 12 for controlling the recirculation valve, and when EGR is switched from ON to OFF, the ignition timing is corrected to the delayed angle side, while if EGR is switched from OFF to ON, the ignition timing is corrected to the advance angle side. |
