Power Steering Pressure Switch: Description and Operation

Power Steering Pressure (PSP) Switch:

PURPOSE
Detects when system pressure increases (turning steering wheel) and signals Powertrain Control Module (PCM).

OPERATION
PCM response to the ON signal (increased load on engine) is to raise idle speed as required by activating the Idle Air Control (IAC) valve. When the switch is exercised it completes a signal path to ground.