Description And Operation: Operation

The EPS module uses input signals received from sensors to vary the current to the electric motor for the desired power steering torque. The boost or assist is variable and speed sensitive, responding to sensors monitoring steering torque, steering wheel speed and angle, and vehicle speed. The steering system is fully integrated with the Electronic Stability Control (ESC) system and helps to compensate in split traction, torque steer, and pull drift (crowned road) situations. Communication is received and transmitted to the EPS module on the Controller Area Network - Chassis (CAN C) data bus.

The EPS module outputs the following actions based on input received:

• Basic Operation  Based on vehicle speed, assists the column rotation based on driver input to decrease steering effort for the driver.
• Variable Servo Steering  When the speed of the vehicle is increased, the module reduces the amount of assistance to the column.
• Active Return  The module commands the motor to quicken the steering wheel in returning to the center position after steering.
• Damping of Steering Return Oscillations  After a steering maneuver, the chassis produces oscillations that the module will then use the motor to try and reduce.
• Selectable Power Assistance 

  Instrument panel driver selectable modes vary the level of power steering assistance in three ways:

  1. Comfort - provides a balance of steering feel and steering effort
  2. Normal - increases steering feel and effort by one level
  3. Sport - provides the greatest amount of steering feel and requires the highest of steering effort