| 摘要 |
PURPOSE:To find out failure of an auxiliary air control(AAC) valve easily at a low cost by detecting respective numbers of revolution of an engine at the time of transmitting full close and full open signals with respect to the AAC valve, and judging pressure of AAC valve failure when the difference between both numbers of revolution is a prescribed value or less. CONSTITUTION:When carbon is attached in the passage of an AAC valve 7, the opening area of a passage 9 is reduced, so that the changing amount of an engine number of revolution is also reduced. In case when an idling rotation control signal output value F is changed from that of a full close signal to that of a full open signal, it the change amount of the engine number of revolution is a reference value or less, it is detected that the carbon is attached in the passage 9 of the AAC valve 7 so as to judge pressure of failure of the AAC valve 7. It is thus possible to find out failure of the AAC valve 7 easily at a low cost. |
