A method may be used to error compensate a measurement of an electric motor's rotor position in a power steering system of a motor vehicle. The electric motor generates torque for assisting steering of the motor vehicle, and stray magnetic fields of motor currents affect the measurement of the rotor position with a magneto-resistive rotor position sensor. The method may involve calculating at least two compensation values based on a current vector, rotor position, and hardware dependent parameters. The at least two compensation values account for errors in the rotor position measurement due to stray magnetic fields of motor currents. The method may also involve calculating a compensated rotor position signal by subtracting the at least two compensation values of the measured rotor position, as well as transferring the compensated rotor position signal as part of a feed-back loop to a target motor torque determination in the motor control.