A first monitoring control circuit unit monitors controlling operation of an engine control unit (ECU); when the occurrence frequency of an abnormality becomes the same as or larger than a predetermined threshold value, a first storage circuit stores that occurrence frequency and a first cutoff circuit de-energizes an intake valve opening degree control motor for an air-intake throttle so as to set the intake valve opening degree to a fixed intake valve opening degree; a second monitoring control means monitors controlling operation of a transmission control unit (TCU); when the occurrence frequency of an abnormality becomes the same as or larger than a predetermined threshold value, a second storage circuit stores that occurrence frequency and a second cutoff circuit de-energizes a gear-shifting electromagnet valve so as to set the transmission ratio to a fixed transmission ratio.