Grand Marquis V8-4.6L Flex Fuel (2010)
Power Steering Pressure Switch: Description and Operation
Power Steering Pressure (PSP) Switch
ENGINE CONTROL COMPONENTS
Power Steering Pressure (PSP) Switch
The 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 provides a low current voltage on the PSP circuit. When the PSP switch is closed, this voltage is pulled low
through the SIG RTN circuit. 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 the transmission EPC pressure during
increased engine load, such as during parking maneuvers.
Typical PSP Switch
