Vehicle electric motor diagnosing apparatus

An electric motor diagnosing apparatus is provided in a vehicle having a generator (7) driven by a drive torque of a drive source, an electric motor (4) driven by electric power supplied from the generator (7), and a wheel (1L or 1R) driven by the electric motor (4). The electric motor diagnosing apparatus comprises a counterelectromotive force determining section (8a) and an electric motor diagnosing section (8b). The counterelectromotive force determining section (8a) determines whether a voltage of electric power supplied from the generator (7) to the electric motor (4) is greater than an induced voltage of a counterelectromotive force of the electric motor (4). The electric motor diagnosing section (8a) drives the electric motor (4) by controlling the generator (7) to supply the electric power to the electric motor (4), and determines whether the electric motor (4) is rotating, upon determining that the voltage of the electric power supplied from the generator to the electric motor (4) is greater than the electric motor induced voltage.