ION CURRENT DETECTING DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To eliminate effects of power voltage rise or vibration between a plurality of ignition coils due to energization/disconnection to the ignition coils disposed in an internal combustion engine comprising a plurality of cylinders on ion current change. SOLUTION: In the ignition coils having overlapping for two or more of them in energization from a battery in a prescribed driving conditions of the internal combustion engine, when an ignition timing Te to an ignition signal for a preceding cylinder falls within an energization start prohibited zone dT based on an energization start timing Ts to an ignition signal determined for a subsequent cylinder, setting for the ignition signal for the subsequent cylinder is changed to a new energization start timing Ts' before the ignition timing Te to the ignition signal for the previous cylinder not to overlap with the energization start prohibited zone dT. An energization monitor determination zone where effects of ion current change are not given can thus be set, thereby energization abnormality in the ignition coil or ignition abnormality such as smoking abnormality in the ignition plug can be correctly detected. COPYRIGHT: (C)2004,JPO