Power Steering Pressure Switch: Description and Operation
Power Steering Pressure SwitchPower Steering Pressure (PSP) Switch:
The Power Steering Pressure (PSP) switch monitors the hydraulic pressure within the power steering system. The PSP switch is a normally closed switch that opens as the hydraulic pressure increases. The PCM uses the input signal from the PSP switch to compensate for additional loads on the engine by adjusting the idle rpm and preventing engine stall during parking maneuvers. Also, the PSP switch signals the PCM to adjust transmission Electronic Pressure Control (EPC) pressure during the increased engine load, for example during parking maneuvers.
The power steering pressure switch:
^ is located on the power steering pump, generates a differential pressure, and is dependent on current input.
^ controls the spool valve in the power steering pump.
^ regulates the hydraulic flow and, when combined with a current controlling device, yields a variable assist power steering system.
^ is controlled by the PCM to increase power steering pump flow and power steering assist at low vehicle speeds and to reduce power steering pump flow and power steering assist at high vehicle speeds.
^ is controlled by the PCM to increase the power steering pump flow, thereby increasing power steering assist for evasive maneuvering at high vehicle speeds (steering wheel rotation rate greater than 22 rpm).