| 摘要 |
PROBLEM TO BE SOLVED: To rapidly detect faults in a fuel supply system. SOLUTION: The difference between air/fuel ratioλdetected by an air/fuel ratio sensor 28 and target air/fuel ratioλTG (1), an air/fuel ratio correction coefficient FAF (amount of feedback correction) (2), and amount of learning correction KGi (3) are used as fault diagnosis data in a fuel supply system, and the three fault diagnosis data (1)-(3) are totalled to obtain a fault diagnosis parameter. After that, the fault diagnosis parameter is subjected to moderating control, and the value is compared with a fault diagnosis reference value to determine the presence or absence of faults in the fuel supply system. As a result, even if the amount of learning KGj is not updated, the faults (namely, the abnormal deviation of the actual air/fuel ratioλ) in the fuel supply system can be detected rapidly from the difference between the actual air/fuel ratioλand the target air/fuel ratioλTG and the air fuel ratio correction coefficient FAF. The abnormal diagnosis reference value is obtained by maps, or the like, according to engine operation parameters, such as amount of sucked air Ga. COPYRIGHT: (C)2005,JPO&NCIPI
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