电控发动机的控制电脑(ECU)具有自诊断功能。在点火开关置于ON位而发动机尚未运转时,ECU就开始不断地监测电控系统的所有传感器、执行元件及其自身是否处于正常工作状态。一旦发现某部件或线路出现故障,ECU即指令故障检查灯(标有CHECK、CHECK ENGINE、SERVICE ENGINE SOON或者画有发动机外形图的灯)点亮,警告驾驶员汽车电控系统已出 Electronic control engine control computer (ECU) has a self-diagnostic function. When the ignition switch is ON and the engine is not running, the ECU continually monitors all sensors, actuators and their own electrically operated systems for normal operation. Once a component or line is found to be faulty, the ECU instructs the fault check light (CHECK, CHECK ENGINE, SERVICE ENGINE SOON, or lamp with engine profile) to light to warn the driver that the vehicle’s electronic control system is out