Power Steering Pressure Switch: Description and Operation

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 this signal.

The battery voltage in the engine control module is applied through a resistor to the power steering pressure switch. Steering operation causes the power steering fluid pressure to increase, turning the switch on. As a result, continuity is produced between the battery voltage applied and ground. This causes the power steering fluid pressure terminal voltage to go from high to low.