Steering: Description and Operation

ELECTRONIC POWER STEERING
The electronic power steering (EPS) system replaces the conventional hydraulic power steering system. A belt driven off the engine does not power steering system. Instead a control module and electric motor is used to regulate the amount of steering assist. The electric power steering system has three major electrical components: the control module, power steering motor and torque sensor. The three components are incorporated into the steering column. The EPS system is a 65 amp system.

CONTROL MODULE
The control module is responsible for the amount of steering assist. The amount of assist is based on vehicle speed, temperature and the amount of force applied to the steering wheel by the driver. Vehicle information, such as vehicle speed, and engine status is provided to the control module via the Class II data line. The control module is also able to control the Service Wrench telltale via the Class II data line. The control module will illuminate this telltale when a failure has occurred in the EPS system.

POWER STEERING MOTOR
The motor is mechanically connected to the steering column through a reduction gear. The control module regulates the amount of steering assist that the motor applies.

TORQUE SENSOR
The torque sensor detects steering torque that is applied to the steering column shaft by the driver. The difference between the input and the output shafts is translated to a voltage that is monitored by the control module.