Power Steering Pressure Switch: Description and Operation

The Power Steering Pressure Switch converts PRESENCE/ABSENCE of power steering load into LOW/HIGH voltage and inputs it to the Engine Control Module, which then controls the Idle Air Control motor based on the signal.







The battery voltage in the ECM is applied through a resistor to the power steering pressure switch. Steering operation causes the power steering oil pressure to increase, turning the switch on. as a result, grounding the signal from the ECM, causing the power steering pressure terminal voltage to switch from HIGH to LOW.