Control device for internal combustion engine

摘要

A target value of an engine load ratio is calculated. A target throttle opening required for making the actual engine load ratio equal to the target engine load ratio is calculated on the basis of an intake pipe pressure which is a pressure in the intake passage downstream of the throttle valve. It is judged whether the target throttle opening can be realized by a step motor. A final target throttle opening is set to a maximum or minimum throttle opening which can be realized by the step motor when it is judged that the calculated target throttle opening cannot be realized by the step motor. The step motor drives the throttle valve so that the actual throttle opening is made equal to the final target throttle opening, and the intake pipe pressure is estimated on the basis of the final target throttle opening.