A rotation state of each rotating element of a four-wheel drive vehicle and an operating state of each engagement element of a disconnect mechanism, corresponding to an operating state of the disconnect mechanism, are displayed on or near a vehicle model image on a vehicle display. Thus, it is possible to inform a driver of the operating state of the disconnect mechanism at any time. Thus, the driver is able to recognize the operating state of the disconnect mechanism at any time, so the driver is able to carry out driving based on the operating state.