Protege L4-1839cc 1.8L DOHC (1990)
Power Steering Pressure Switch: Description and Operation
The Power Steering Pressure Switch is an "ON/OFF" switch that detects when system pressure increases (turning steering wheel) to cause a load on the
engine. ECU response to the "ON" signal is to raise idle speed as required by activating the ISC valve and to initiate A/C cut-off until the load
decreases.