Refrigerant Pressure Sensor / Switch: Description and Operation
A/C PRESSURE TRANSDUCERThe A/C pressure transducer is located on the discharge line near the condenser and functions as a refrigerant system pressure sensor. This switch prevents compressor operation when the discharge line pressure approaches extreme levels. The transducer is a factory-calibrated unit and cannot be adjusted or repaired. If faulty or damaged, it must be replaced.
When discharge line pressure rises above 2971 kPa (431 psi) the switch contacts open and interrupt the A/C clutch relay signal from the PCM. The switch contacts also open when pressure drops below 206 kPa (30 psi).