Power Steering Pressure Control Valve: Description and Operation

P Valve-Purpose, Design And Function (Part 1 Of 2):

P Valve-Purpose, Design And Function (Part 2 Of 2):

FUNCTION OF SPS P-VALVE
The P-valve is actuated in cycles with approx. 6V by the Electronic Traction System (ETS), Acceleration Slip Regulation (ASR) or Electronic Stability Program (ESP) control module.

K Characteristic:

As vehicle speed increases the current flow reduces and the P-valve opens the control restrictor continuously in accordance with a characteristic (K) defined in the control module. Consequently the oil flow is controlled and also the steering wheel torque.

P-Valve Open:

P-Valve Closed:

If the valve is fully energized, (v = 0 km/h), the control restrictor is closed. Consequently there is no oil flow and the lowest steering wheel torque is adjusted (parking situation).