Variable Effort Steering System Operation

The MAGNASTEER(R) system is a speed-dependent power steering system. The system provides power assist at varying levels depending on need. A bi-directional magnetic rotary actuator in the steering gear adjusts the amount of torque (driver effort) necessary to turn the steering wheel. The MAGNASTEER(R) system is controlled through the Antilock Brake System (ABS) module and varies the torque by adjusting the current flow through the actuator. The amount of adjustment is directly related to vehicle speed. The controller receives speed-related input signals from the vehicle speed sensor. The system operation begins with input from the ABS wheel speed sensors to the Electronic Brake Traction Control Module (EBTCM). As the vehicle speed increases, the EBTCM varies the current flow to the MAGNASTEER(R) actuator in order to vary the rate of input torque required at the power rack and pinion.