| 摘要 |
PURPOSE:To perform safety operation of an engine, by controlling an exhaust gas recirculation amount in accordance with speed of the engine when an idle speed control actuator is detected abnormal in an electronic engine control device. CONSTITUTION:An engine, equipped with an electronic control device 12, uses various actuators, and the actuators, if caused a trouble, can not perform adequately correct control operation. Now the actuator 7 in an idle speed control system is in failure, if a throttle valve is left as opened, speed of the engine is rapidly inceased in an idle state. This condition is decided as a fault by a control logic 22 through an idle detection signal THSW and speed signal N, then the speed under the idle condition is compared with a prescribed speed, previously given as a function of engine temperature, and the on-duty of an exhaust gas recirculation (EGR) solenoid is changed to control speed of the engine. |
