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.
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.
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.

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

F-CAN Communication Data
EPS System Receiving Signal
Transmitting Unit
Signal Name
PCM
Engine speed signal
Vehicle speed signal*1
Cruise control status
Integrated drive-mode signal*4/*5
Service check signal
System failure information
TCM*2
Vehicle speed signal
System failure information
VSA modulator-control unit
Wheel speed signal
Vehicle understeering status
Estimated longitudinal acceleration signal
Estimated L/R ? differential signal
System failure information
SRS unit
Yaw rate signal
Lateral acceleration signal
Longitudinal acceleration signal
System failure information
Millimeter wave radar*3
LKAS mode signal
Instructing current signal
System failure information
*1: M/T
*2: CVT
*3: With LKAS
*4: Si
*5: Type-R

EPS System Transmitting Signal
Transmitting Unit
Signal Name
EPS control unit
Indicator drive request signal
Motor load status
Idle control demand
Steering angle signal
Steering angle speed signal
Steering torque signal*
Motor speed signal*
System failure information
*: With LKAS