F 150 Heritage 2WD Pickup V8-4.6L SOHC VIN W (2004)
Power Steering Pressure Switch: Description and Operation
Power Steering Pressure Switch
POWER STEERING PRESSURE SWITCH
Power Steering Pressure (PSP) Switch
The power steering pressure (PSP) switch (Figure 45) 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.