This paper presents an engineering design of a real-time fault monitoring method for power-on-wheel electric vehicles, which have four independent wheel units. Each independent unit has an in-wheel motor with its own steering control system. A central control unit is used to coordinate the four wheels and translate the driver's idea onto the wheels, as such there is no mechanical link between these wheel units. In this repect, the electric car differs from traditional vehicles. The experiment from workshop tests and drive tests proved that this real-time fault monitoring method based on motor drive operational current is a feasible design to identify the performance of the in-wheel motors.