| 摘要 |
PROBLEM TO BE SOLVED: To inhibit a drop in engine torque while preventing knocking in an abnormal state of an alcohol concentration detection means, in a system setting ignition timing according to the alcohol concentration of fuel. SOLUTION: When it is judged abnormality of the alcohol concentration detection means (an alcohol concentration detection function of ECU 43 or an alcohol concentration sensor) exists, ignition timing retarded from ignition timing in a normal state of the alcohol concentration detection means by only retardation quantity necessary for preventing knocking is set by setting predetermined alcohol concentration lower than alcohol concentration detection value right before the judgment of abnormality as alcohol concentration for calculating ignition timing, and calculating ignition timing according to the alcohol concentration for calculating ignition timing (predetermined alcohol concentration) and an engine operation state with using an ignition timing map same as one in the normal state. Consequently, drop of engine torque is inhibited by inhibiting retardation quantity of ignition timing from getting excessive while preventing knocking in the abnormal state of the alcohol concentration detection means. COPYRIGHT: (C)2009,JPO&INPIT |
