A TOYOTA car engine can't start. Fault diagnosis: the car is equipped with a 3S electric jet engine, because the storage time is too long and the battery is lost, the owner can still be able to repair the battery after replacing the battery. After inspection, it is found that the pole column of the control unit is in reverse. After correction, you can't drive the car, check again, no high pressure fire. After that, the EFI fuse was found to burn and the fuse was burned and wrapped in copper wire. After the routine inspection, the control unit was removed. After opening the casing of the engine control unit, it was found that a printed copper foil was clearly burned on the circuit board, and a high power diode was burnt out. After replacing the diode and re welding the printed printed copper foil, the loading test was still not a car. After inspection, there were cracks on the ignition coil, and the ignition coil was also found to be the same. Burn out and replace the new ignition coil. Through the components of the car, it can be thought that after the battery was connected, the EFI fuse was burned, the maintenance personnel did not understand the cause, and then the fuse was reloaded, and the control unit and the ignition coil were burnt out.