*It basically adjust the steering feel when going thru a parking lot and then tightens up when on the highway or Interstate*.
almost......lol, not quite....
the sensor is there to 1. disengage the a/c .... 2. send a signal to the ecm to raise the engine rpm when the vehicle speed is so slow that the engine rpm is to low to adequately assist the needed power steering pressure.
When the pressure in the system drops to a pre determined pressure that switch opens, the ecm *sees* that & raises the engine rpm to increase the pump rpm & power steering pressure.
The sensor is referred to as Idle Speed Power Steering Pressure Switch