Refrigerant Pressure Sensor / Switch: Description and Operation
A/C Pressure SwitchThe 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 lack of airflow at the condenser), or too low (due to leakage), the A/C pressure switch stops the A/C request signal to the PCM and the compressor stops operating.
- Middle pressure switch
If the refrigerant pressure goes above or below 1,470 kPa (15.0 kgf/sq.cm, 213 psi), the A/C pressure switch opens or closes to signal the PCM to change the speed of the condenser fan and radiator fan (high-low).