EPS System Description - System Diagram

• The steering force of the steering wheel is detected by the torque sensor, and the signal is sent to the EPS control unit. The EPS control unit calculates the assistance torque based on the steering torque signal and vehicle speed signal, and activates the motor to assists the steering force.
• To activate the three-phase brushless motor properly, the motor angle sensor detects the motor angle, and sends the signal to the EPS control unit.
• The EPS control unit sends the motor load status to the PCM. If the electric load of the motor is high while the vehicle is idling or running at a low speed, the PCM increases the idling speed to avoid engine stall.
• The EPS control unit receives the vehicle behavior information from the VSA modulator-control unit and the SRS unit.
• When the steering wheel is operated during auto idle stop, the EPS control unit sends an engine restart request to the PCM to start the engine.
• The EPS control unit assists the steering force when the EPS control unit receives the steering assist request from the millimeter wave radar.
• When the EPS system detects a problem, the EPS control unit stores the DTC, and sends the signal to the gauge control module to cause the EPS indicator to come on.

For locations of each component on the vehicle, refer to Component Location Index:

• EPS control unit, EPS motor, Torque sensor, EPS motor angle sensor 
• Gauge control module
• PCM
• VSA modulator-control unit, Steering angle sensor
• SRS unit
• Millimeter wave radar - Refer to: Adaptive Cruise Control (ACC) Component Location Index or Lane Keeping Assist System (LKAS) Component Location Index

Courtesy of HONDA, U.S.A., INC.

F-CAN Communication Data 

EPS System Receiving Signal 

EPS System Transmitting Signal