Fault diagnosis device and method for high-pressure common-rail fuel injection system

The invention discloses a fault diagnosis device and method for a high-pressure common-rail fuel injection system. Before the oil pump magnetic valve operates, the controller can read the diagnosis feedback signal of an oil pump magnetic valve fault diagnosis device and determine whether the magnetic valve has an open-circuit fault; when the magnetic valve operates, the controller can read the corresponding signal and determine whether a short-circuit fault and a reliability fault occur; before the fuel injector starts actuation, the controller can read the diagnosis feedback signal of the injector and determine whether the fuel injector is subjected to short-circuit fault to earth; then the low end switch is turned on, the controller can read the signal once again and determine whether the open-circuit fault appears; when the injector starts operating, the controller can read the corresponding signal and determine whether the inside short-circuit fault and the reliability fault appear. The fault diagnosis device and method can provide corresponding protections when the oil pump and the injector break down and can protect the engine and the electronic control system thereof. The hardware circuit device is simple and effective and the software cost is low, thus, the reliability of high-pressure common-rail electronic control system can be improved.