MALFUNCTION DETERMINATION DEVICE FOR HYBRID VEHICLE

摘要

A malfunction determination device provided to a hybrid vehicle, the malfunction determination device being capable of selecting a series mode in which front wheels or rear wheels are driven by a drive motor to cause the vehicle to travel while a motor generator is driven to generate power by an engine (2) installed in the vehicle, and also being capable of motoring in which the fuel supply to the engine (2) is stopped and the motor generator is driven by power supplied from a drive battery to forcefully rotate the engine (2), wherein: an engine control unit (22) has functions for halting the series mode while the series mode is in effect and executing motoring, and for determining malfunctions of exhaust system sensors (34, 35) on the basis of the detection values of the exhaust system sensors (34, 35) at the stopping and restarting of the fuel supply to the engine (2); and the engine control unit regulates motoring and does not perform malfunction determination for the exhaust system sensors (34, 35) when the vehicle speed is a low speed less than a prescribed threshold value Va.