METHOD OF ESTIMATING THROTTLE VALVE OPENING

摘要

PROBLEM TO BE SOLVED: To provide a method of estimating a throttle valve opening capable of accurately estimating an opening of a throttle valve based on an intake air amount detected by an air flow meter when an engine works normally.SOLUTION: In the method of estimating a throttle valve opening, an opening of a throttle valve is estimated when an intake valve closing timing is retarded and an intake air passes through the throttle valve at subsonic speed. The method includes: a first step of advancing the intake valve closing timing such that the intake air may pass through the throttle valve at sonic speed (step 103); a second step of detecting an intake air amount using an air flow meter (step 104); and a third step of estimating the opening of the throttle valve based on the intake air amount detected by the air flow meter (step 105).