Refrigerant Pressure Sensor / Switch: Description and Operation

PURPOSE
Provides input to the Powertrain Control Module (PCM) and Constant Control Relay Module (CCRM) to control clutch cycling. Controls evaporator core pressure at a point where plate/fin surface temperature is maintained slightly above freezing, preventing evaporator icing and blockage of air flow.

OPERATION
A/C Clutch Cycling Pressure Switch closes at 45 psi increasing and opens at 2.45 psi decreasing.