故障现象一辆五菱之光LZW6371车,搭载LJ465Q-1AE3发动机(采用MOTOROLA电控系统),该车在行驶中发动机突然熄火,无法再次起动着机。故障诊断经初步检查,发现火花塞不跳火,喷油器不喷油;检查点火线圈和喷油器的供电,正常;用二极管试灯进行测试,发现起动发动机时,发动机控制单元没有输出点火信号和喷油信号,由此怀疑曲轴位置传感器信号异常。检查曲轴位置传感器及其线路,未见异常。保险起见,更换曲轴位 Fault phenomenon A Wuling light LZW6371 car, equipped with LJ465Q-1AE3 engine (using MOTOROLA electric control system), the car suddenly turn off the engine while driving, can not start the machine again. Fault diagnosis After the initial inspection found that spark plugs do not jump, the injector does not inject fuel; check the ignition coil and injector power supply, normal; test with the diode test light and found the engine start, the engine control unit does not output the ignition signal And the fuel injection signal, thereby disregarding the crankshaft position sensor signal abnormality. Check the crankshaft position sensor and its wiring, no abnormalities. To be safe, replace the crankshaft