To compare the frequency analytical result of engine rotary speed signal frequency analytical means and

摘要

PROBLEM TO BE SOLVED: To solve the problem in which rotation fluctuation of wheels is transmitted to an engine side through a propeller shaft, when a vehicle travels on a rough road, to cause rotation fluctuation of the engine, and since determination of misfire is detected based on rotating angular velocity change of the engine, wrong determination of misfire may be caused in the rough road traveling.;SOLUTION: In misfire determination, whether the rotation fluctuation is caused by misfire or resulted from the road surface state is determined by comparing a frequency analytic result of a vehicle speed sensor signal with a frequency analytic result of a crank angle sensor, and when it is determined to be resulted from the road surface state, the misfire determination is stopped.;COPYRIGHT: (C)2007,JPO&INPIT