A method and unit to control a steering system for a road vehicle, which steering system adjusts the steering angle of the front wheels of the road vehicle by means of a steering wheel in a preliminary design and optimization step, an actual transmission error is determined, caused by the mechanical structure of a transmission device of the steering wheel which mechanically connects a steering wheel to a steering rod mechanically connected to the hubs of the front wheels the current angular position of the steering wheel is measured and the intensity of the servoassistance force applied by a servomechanism to the steering rod is changed as a function of the current angular position of the steering wheel and as a function of the actual transmission error.
