Module, Electric Power Steering (EPSM): Operation

WARNING: This page is about a different car, the 2017 Dodge Charger. However, it is still accessible from the selected car via links, so may be relevant.

NOTE:

All diagnostics must be done through the electric power steering module for the electric power steering system. There are no serviceable parts inside the column, module or motor. If any part is found to be defective or needs replacement, the column, motor, and module are serviced as a assembly. If the EPS assembly is replaced, a verification test must be performed. Refer to EPS VERIFICATION TEST .

The Electric Power Steering (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 vehicle's electronic stability control 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 CAN line.

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.