Power Steering Pressure (PSP) Switch

1999 Mercury Tracer LS, 4D Sedan, StandardSECTION Power Steering Pressure (PSP) Switch
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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 SIGRTN 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.

Fig 1: Identifying Typical PSP Switch
G06053895Courtesy of FORD MOTOR CO.
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