Power Steering Pressure Switch: Description and Operation

Power Steering Pressure Switch:

PURPOSE
The Engine Control Module (ECM) uses the signal to modify injector opening time to compensate for the extra load being placed on the engine at idle.

OPERATION
When the steering wheel is moved at idle speed, the Power Steering switch senses the change in pressure and closes, sending a ground signal to the fuel ECM. On receiving this signal, the ECM increases idle speed to compensate for the additional load from the power steering pump.