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.
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.
With LKAS: The EPS control unit assists the steering force when the EPS control unit receives the steering assist request from the millimeter wave radar.

For locations of each component on vehicle, refer to Component Location Index:
F-CAN Communication Data
EPS System Receiving Signal
Transmitting Unit
Signal Name
Gauge control module
Driver's door switch signal*1
Wiper switch status*1
System operating state signal*1
PCM
Engine speed signal
Vehicle speed signal*2
Shift position signal*2
Service check signal
System failure Information
TCM*3
Vehicle speed signal
Shift position signal
VSA modulator-control unit
Wheel speed signals
System operating state signal
System failure Information
SRS unit
Yaw rate signal
Lateral acceleration signal
Longitudinal acceleration signal
Driver's seat belt buckle switch status*1
Millimeter wave radar*4
LKAS mode signal
Instructing current signal
*1: With driver attention monitor
*2: K24W9/K24V9 engine
*3: L15BE engine
*4: With LKAS

EPS System Transmitting Signal
Transmitting Unit
Signal Name
EPS control unit
Indicator drive signal
Motor load status
Idle control demand
Steering angle signal
System failure Information
Driver attention monitor information signal*1
Steering torque signal*2
Motor speed signal*2
*1: With driver attention monitor
*2: With LKAS