Power Steering Pressure Switch: Description and Operation
DESCRIPTIONThe Power Steering Pressure (PSP) switch signals the Engine Control Module (ECM) when the vehicle is in need of power steering assist. The turning of the steering wheel causes increased power steering fluid pressure which will close the PSP switch. The ECM uses this signal to control the Idle Air Control (IAC) valve to raise the idle speed before the load can cause a poor idling condition. The PSP switch is located in the power steering pump housing.