Abstract: A motor vehicle power steering system, including a steering column and a power steering motor. The column has an upper part bearing a steering wheels and a lower part acting on a mechanical steering device. At setpoint at which the motor should apply a power assist to the steering columns is set on the basis of information concerning the torque exerted on the steering wheel. The information is obtained by measuring angles at the steering wheel and at the lower part of the column, and the setpoint is established by comparing the two angle measurements, taking into account the rigidity of the steering column between the two angle-measuring points.