Misfire determination device, hybrid automobile, and misfire determination method

摘要

At a Lo gear position of a transmission, the engine misfire detection process of the invention sets a first threshold value A1 and second threshold values to be referred to for detection of an engine misfire (steps S220 and S280) and detects an engine misfire based on the settings of the first threshold value A1 and the second threshold values and 360-degree differences ”360 computed from 30-degree rotation times T30 given as a time required for rotation of a crankshaft by every 30 degrees (steps S230 and S290). At a Hi gear position of the transmission, the engine misfire detection process of the invention sets a first threshold value A2, which is to be smaller than the first threshold value A1, and second threshold values (step S330 and S390) and detects an engine misfire based on the settings of the first threshold value A2 and the second threshold values and the 360-degree differences ”360 (step S340 and S400). The engine misfire detection process of the invention detects the occurrence of an engine misfire at each gear position of the transmission by taking into account the varying effects of the operating conditions of a motor MG2, the transmission, and a planetary gear mechanism on the crankshaft of the engine.