Power Steering) - SSANGYONG Rexton 2007 Manual

0-30 4620-12
3) CIRCUIT DESCRIPTION
(1) SSPS (SPEED SENSITIVE POWER STEERING)
In the conventional constant power assist steering system, the steerability gets lighter as
vehicle speed rises, and this may cause a dangerous situation. Where as having heavy
steerability in high speed driving makes it difficult to manipulate the steering wheel when
vehicle is in stop. This steering system solves this problem as the steerability is changed
according to the vehicle speed, which is called Speed Sensitive Power Steering (SSPS).
SSPS, by providing appropriate steerability to a driver according to the changes of vehicle
speed, gives steering stability. The power steering control unit adjusts the hydraulic pressure
to reaction plunger by controlling the pressure solenoid valve located in the gear box to
optimize the steerability. In other words, the steering wheel gets lighter by adjusting
steerability in stop or low speed and provides steering stability by adjusting steering wheel to
become heavier in high speed.
(2) INPUT/OUTPUT OF SSPS CONTROL UNIT
(3) SSPS CONFIGURATION
A. PCV (Pressure Control Valve)
This valve controls the hydraulic pressure supplied to reaction device by moving the spool
valve according to the changes of solenoid valve.
B. Reaction device
This device increases the steerability effect by binding the input shaft with supplied hydraulic
pressure from PCV.
CIRCUIT
REXTON 2007.09
C. Solenoid valve
The SSPS control unit controls the amount of electric current to the solenoid valve according
to the vehicle speed. In other words, the solenoid valve controls the hydraulic pressure
applied to reaction plunger by changing the valve spool position that is linked with solenoid
valve according to the amount of electric current. The changes of hydraulic pressure applied
to input shaft according to the pressure changes applied to the reaction plunger provide
proper steerability based on the amount of electric current.
▶ Specifications
▶ Electric Current Check
· Disconnect the solenoid valve connector (waterproof connector) and install the
ammeter between the solenoid valve connector and the wiring harness.
- Do not ground the solenoid terminal.
- When the vehicle speed is at 0 km/h, check whether the electric current for solenoid
is in specified range and check that the current is reduced as the vehicle speed
increases.
Current
D. SSPS Control Unit
- To provide proper steerability to a driver, the SSPS control unit controls the solenoid
valve by receiving the vehicle speed and the throttle position data via CAN
- communication.
The SSPS control unit controls the working current for the solenoid valve with PWM type
duty ratio of 333 Hz frequency and sets the target current to 1A during 1 second after the
- ignition is "ON".
When a trouble occurs in the system, the SSPS control unit generates a trouble code
using fail safe function.
0.9 ~ 1.1 A (vehicle speed at 0 km/h)