| 摘要 |
PROBLEM TO BE SOLVED: To increase the reliability of response delay diagnosis by evaluating whether the response delay diagnosis in a variable valve train using an electromagnetic actuator functions normally or not. SOLUTION: A delayed operation state in the variable valve train is apparently generated by installing a power voltage changing module 201 forcibly lowering the power voltage of the electromagnetic actuator 54. In the lowered state of the power voltage, if a response delay in a direction for increasing the current of the electromagnetic actuator 54 is not diagnosed, it is evaluated that abnormality occurs in a response delay diagnosis function. A response delay is forcibly produced by switching a gain used for the feedback control of a variable valve timing device. In this state, the response diagnosis is performed. When the occurrence of the response delay by the switching of the gain is not diagnosed, it is evaluated that the function of the response diagnosis is defective. COPYRIGHT: (C)2006,JPO&NCIPI
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