A method of controlling an electric motor of a power steering system having at least three windings is described, wherein a control unit applies a current to the windings of the electric motor to generate a total torque having a value which is ascertained by the control unit from a set-point torque for steering assistance and a set-point torque for damping. A damping set-point circuit ascertains the set-point torque for damping and a steering assist set-point circuit ascertains the set-point torque for steering assistance. A monitoring circuit monitors the function of the windings of the electric motor. In the event of a malfunction of any of the windings, the monitoring circuit outputs an error signal, upon which the set-point torque for steering assistance is reduced.