Refrigerant Pressure Sensor / Switch: Description and Operation

A/C Pressure Switch (Type S Model)

The A/C pressure switch consists of a High-Low pressure switch (A/C pressure switch A) and a Middle pressure switch (A/C pressure switch B).




- High-Low pressure switch
If the refrigerant pressure becomes too high (due to blockage), or too low (due to leakage), the A/C pressure switch sends a signal to the PCM to prevent the compressor from operating.




- Middle pressure switch
If the refrigerant pressure goes above or below 1,520 kPa (15.5 kgf/sq.cm, 220 psi), the A/C pressure switch sends a signal to the climate control unit to change the speed of the condenser fan and radiator fan (High-Low).