| 摘要 |
A method of controlling an exhaust gas recirculating quantity in an internal combustion engine, which is adapted to detect, by a valve opening sensor, actual valve opening of an exhaust gas recirculating valve arranged across an exhaust gas recirculating passageway communicating the exhaust passage of the engine with the intake passage of same, calculate the difference between the detected actual valve opening value and a desired valve opening value set in response to operating conditions of the engine, and actuate the exhaust gas recirculating valve to close or open by operating a valve actuator so as to minimize the difference. When a time interval at which the sign of the difference between the actual valve opening value and the desired valve opening value has been inverted exceeds a predetermined period of time, it is determined that the exhaust gas recirculation control system including the valve opening sensor has developed an abnormality. Preferably, the exhaust gas recirculation control system is determined to be abnormal when the number of times of inversion of the sign of the difference between the actual valve opening value and the desired valve opening value does not reach a predetermined number of times within a predetermined period of time. |
