故障现象一辆一汽丰田花冠轿车,因交通事故导致其左前部损伤,但维修后出现发动机不能起动着机的现象。故障诊断试车发现,起动机能正常工作;连接故障检测仪,却显示无法通讯;发动机故障指示灯在接通点火开关时不点亮。检查发动机,发现在起动时没有点火和喷油;检查相关执行元件,发现它们的电源供应不稳定。检查发动机室内左前的主接线盒,EFI熔丝正常;跨接主继电器(图1手所 Fault phenomenon A FAW Toyota Corolla car, due to an accident caused by the left front of his injury, but after the repair of the engine can not start the machine’s phenomenon. Troubleshooting test drive found that the starter can work; connect the fault detector, but showed no communication; engine fault indicator light does not turn on when the ignition switch. Check the engine and found that there was no ignition and fuel injection at start-up; check the relevant actuator and find that their power supply is not stable. Check the engine compartment left front of the main junction box, EFI fuse normal; across the main relay (Figure 1 hands