A motor controller 21 has a driving system diagnostic unit 21 a. A battery management controller 32 receives information indicating abnormality of a driving system 20 from the motor controller 21. An indicator 41 of a battery unit 30 indicates a remaining power of a battery 31 and the abnormality of the driving system 20. In this case, it is possible for an occupant to prevent erroneous recognition that an assist force of the electric motor is decreased due to the remaining power of the battery becoming zero when the assist force of the electric motor is decreased due to abnormality of the driving system.
