| 摘要 |
PURPOSE:To prevent an idling speed from increasing so abnormally, by installing a judging device which judges anything trouble on a car speed sensor in a device bearing the above caption, while forbidding feedback control over an engine speed in time of trouble judgement. CONSTITUTION:At the time of detecting an idling state with an idle switch 25, a device bearing the above caption controls the opening of a throttle valve 11 to be installed in a suction passage for feedback to keep up an engine speed to the desired one by an actuator 12 in conformity with the output of an idling state detecting device inclusive of an engine speed sensor 17 and a car speed sensor 24 via a controller 29. In this case, in a state that a suction air quantity of more than the specified value is being detected by an air flow sensor 16, whether frequency of the output of the car speed sensor 24 is smaller than the setting value or not is judged. And, when YES judgment is the case, it is judged that the car speed sensor 24 gets out of order and thereby the said feedback control is made so as to be forbidden. |
