Patent ID: 7448459

Claim:
A method for detecting an abnormality in a hybrid vehicle that comprises an engine that can run in a cylinder cut-off state where intake and exhaust valve lifts are made zero, and a motor/generator that functions as both a motor and a generator, the vehicle traveling by means of the power of at least one of the engine and the motor/generator and carrying out regenerative braking by the motor/generator while running the engine in a cylinder cut-off state during deceleration, the method comprising the steps of: determining that detection of whether in a negative intake pressure sensor is in a state incapable of carrying out a normal function of sensing a negative intake pressure is desired when the engine is running in said cylinder cut-off state during deceleration; prohibiting the engine from running in said cylinder cut-off state even during deceleration so as to allow a negative intake pressure to be generated in the engine; then detecting a magnitude of the negative intake pressure by said negative intake pressure sensor in a state where the cylinder cut-off state is prohibited; and determining that an abnormality does not exist in said negative intake pressure sensor if said detected magnitude of the negative intake pressure exceeds a predetermined threshold.