| 摘要 |
The present invention relates to a valve characteristic control apparatus of an internal combustion engine, including a camshaft (22) provided with a cam (27), and a valve lift-varying mechanism (22a, 36) that allows an amount of valve lift of an engine valve to be varied in accordance with a displaced position of the camshaft (22) in the direction of the axis of the cam, the apparatus comprises a sensor (126) that detects an actual amount of valve lift and outputs a signal; and a controller (130) that receives the signal from the sensor (126) and diagnoses that there is an abnormality of the valve lift-varying mechanism, provided that a deviation between the actual amount of valve lift and a target amount of valve lift of the engine valve is greater than a predetermined value and that at least one of the following conditions is met: (a) an amount of change in the actual amount of valve lift is less than a predetermined change value; (b) the controller has been in a state of outputting an instruction to the valve lift-varying mechanism to maintain the amount of valve lift for a predetermined duration; and (c) there is no abnormality in a retainment control system while the controller is in a state of outputting an instruction to the valve lift-varying mechanism to maintain the amount of valve lift. <IMAGE> |
