Power Steering Pressure Switch: Description and Operation

Power Steering Pressure Switch:

PURPOSE
To sense high pressure in the steering box and signal the ECM to adjust the idle speed accordingly.

OPERATION
The Power Steering Pressure Switch (PSPS) opens during high pressure power steering situations. When the power steering switch is open, power to the A/C relay is shut "OFF," resulting in A/C compressor clutch disengagement. Also, a signal is sent to the ECM. The ECM uses this signal to compensate for the additional engine load by moving the IAC valve.