With 4WAS

EPS SYSTEM : System Description


DESCRIPTION
- The EPS system controls the power steering solenoid valve with 4WAS main control unit.





- The power steering solenoid valve control changes the power steering solenoid valve activation voltage according to the vehicle speed.

SYSTEM DIAGRAM






Sectional View











OPERATION PRINCIPLE
When turning the steering wheel to the right.

During Parking





1. Power steering solenoid valve is closed while a vehicle is stopped.
2. Pinion "1R", "2R" and "3R" are closed depending on steering torque of steering wheel.
3. Oil pressure "P" in the gear housing assembly is the sum of oil pressures occurring in "2R" and "3R". This results in a light steering force because of high pressure.

During High-speed Operation





1. Power steering solenoid valve is opened during high-speed operation.
2. Pinion "1R", "2R" and "3R" are closed depending on steering torque of steering wheel.
3. "2R" is bypassed to the return port by the EPS solenoid valve.
4. Oil pressure "P" in the gear housing assembly includes only oil pressure occurring in "3R" and results in a heavy steering force.