Method of controlling an electric motor of a power steering system, and power steering system

A power steering system comprising:

• an electric motor for steering assistance;
• a monitoring circuit for monitoring the electric motor;
• a control unit for controlling the electric motor;
• a steering assist set-point circuit for determining a set-point torque for steering assistance;
• a damping set-point circuit for determining a set-point torque for damping;
• and
• an error control for reducing the set-point torque for steering assistance;
• wherein the electric motor includes at least three windings to which a current can be applied by the control unit to generate a total torque, the control unit ascertaining the total torque from the set-point torque for steering assistance and the set-point torque for damping, and the monitoring circuit monitoring proper function of the electric motor and, in the event of a malfunction of any of the windings, transmitting an error signal to the error control which thereupon reduces the set-point torque for steering assistance.