| 摘要 |
PROBLEM TO BE SOLVED: To securely prevent freezing of a throttle valve without giving a bad influence to drivability. SOLUTION: When the predetermined condition for carrying out the throttle freezing preventing control (for example, intake air temperature at the predetermined value or less) is satisfied, final target throttle opening THR is periodically changed in an opening range (THR0±D) around the basic target throttle opening THR0 set in response to the quantity of accelerator operation, and the throttle valve is forcibly driven to be opened and closed to prevent freezing of the throttle valve. Furthermore, the quantity of ignition timing correction IAES and the quantity of intake valve timing correction IVT are computed to offset an output fluctuation of an engine due to the forcible drive of the throttle valve, and ignition timing and the intake valve timing are corrected to prevent an output fluctuation of the engine. Forcible drive amplitude D of the throttle valve is set in response to the engine operating condition to obtain the freezing preventing effect of the throttle valve. COPYRIGHT: (C)2003,JPO
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