| 摘要 |
<P>PROBLEM TO BE SOLVED: To enhance reliability of a high pressure fuel supply system, and to diagnose abnormality adequately when a pressure limiter (pressure release valve) is opened. <P>SOLUTION: A common rail 20 is provided with the pressure limiter 27 which opens when a fuel pressure therein reaches a predetermined valve opening pressure. An ECU 50 determines that the pressure limiter 27 opens, and when the opening is determined, the ECU 50 instructs reduction of a fuel discharge amount of a fuel pump 11. Specifically, a target rail pressure in discharge amount feedback control of the fuel pump 11 is set to a lower value than a valve closing pressure of the pressure limiter 27. The fuel pressure in the common rail 20 after instruction of discharge amount reduction is detected, and the abnormality of the high pressure fuel supply system is diagnosed based on the detection result. <P>COPYRIGHT: (C)2010,JPO&INPIT |
