Power Steering Pressure Switch: Description and Operation

Power Steering Pressure Switch (Typical):

LOCATION

The power steering pressure switch is mounted on the power steering pump.


PURPOSE

The switch signals the engine controller when a power steering load is put on engine.


OPERATION

This switch senses the pressure of the power steering system and sends a signal to the engine controller to adjust the engine rpm when the engine load is high and the engine speed is low (i.e. when the vehicle is being parked).

When the power steering system pressure exceeds 1896 kPa +/- 172 kPa (275 psi +/- 25 psi), the engine controller will increase the idle rpm via the Idle Speed Actuator (ISA) Motor so that the engine will not stall.