摘要 |
A redundant mechanism includes two pressure regulating valves for covering one of the pressure regulating valves when the other one is in a defective condition. First and second pressure regulating valves are provided as pressure regulating members of the fuel injection circuit. The valves are connected to the reflux passage and the by-pass passage that communicates with the fuel injection passage via the first and the second orifices, respectively. First and second sensors are provided for detecting the fuel pressure applied on the respective pressure regulating valves separately. A controller of the failure diagnostic member compares the fuel pressures P1, P2 detected by the first and second sensors and the predetermined fuel pressure P in the fuel injection passage. If P1=P2, both of the first and the second pressure regulating valves are determined to be normal. When a defective operating condition occurs in one of the pressure regulating valves, P1 and P2 vary. Therefore, it is determined to be abnormal based on the differential pressure and a display is activated.
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