A/C Pressure Sensor
Some models are equipped with an air conditioner pressure sensor which is used to inform ECM of A/C system pressure levels. Low pressure signal will cause ECM to disengage the A/C compressor to prevent system damage. High pressure levels cause ECM to energize high speed fans while A/C compressor clutch is engaged. Extremely high pressure levels will cause ECM to disengage A/C compressor clutch to prevent system damage.