System Description
- EPS system consists mainly of EPS control unit, EPS motor, torque sensor.
- EPS system calculates a control signal to transmit to the EPS motor based on information received from ECM, ABS actuator and electric unit (control unit), steering angle sensor and combination meter via CAN communication.
- EPS control unit performs an arithmetical operation on data, such as steering wheel turning force (sensor signal) from the torque sensor, vehicle speed signal, etc. Then it generates an optimum assist torque signal to the EPS motor according to the driving condition.
- After engine start, the EPS system performs control.
- When a malfunction occurs in the system, the fail-safe function stops the EPS system (manual steering state) or restricts its operation (Constant steering assist level state). Refer to Fail-safe .
- EPS control unit decreases the output signal to EPS motor while extremely using the power steering function (e.g., full steering) consecutively for protecting EPS motor and EPS control unit (Overload protection control). Refer to Protection Function .
SYSTEM DIAGRAM
INPUT SIGNAL AND OUTPUT SIGNAL
Communicates the signal from each control unit via CAN communication:
| Control unit | Signal status |
|---|---|
| ECM | Transmits the following signals to EPS control unit via CAN communication:
|
| Chassis control module (with built in steering angle sensor) (With automatic brake hold) | Transmits the following signal to EPS control unit via CAN communication:
|
| Steering angle sensor (Without automatic brake hold) | |
| ABS (Anti-lock Braking System) actuator and electric unit (control unit) | Transmits the following signal to EPS control unit via CAN communication:
|
| Combination meter | Transmits the following signal to EPS control unit via CAN communication:
Receives the following signal from EPS control unit via CAN communication:
|
CONDITIONS FOR POWER STEERING WARNING LAMP ON
- Turns ON when there is a malfunction in EPS system. If indicates that fail-safe mode is engaged and enters a manual steering state (Control turning force steering wheel becomes heavy).
- Also turns ON when ignition switch ON, for purpose of lamp check. Turns OFF after the engine starts, if system is normal.
| Condition | Power steering warning lamp |
|---|---|
| Ignition switch ON. (Lamp check) | ON |
| After engine start (steering assist force is generated) | OFF |
| When steering assist is stopped | ON |