Refrigerant Pressure Sensor / Switch: Description and Operation
A/C PRESSURE TRANSDUCERA/C Pressure Transducer:
The A/C pressure transducer is installed on the liquid line fitting located at the top of the receiver/drier. A rubber O-ring seals the connection between the transducer and the fitting. Three terminals within a molded plastic connector receptacle on the top of the transducer connect it to the vehicle electrical system through a wire lead and connector.
The A/C pressure transducer cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
The A/C pressure transducer monitors the pressures in the high side of the refrigerant system through its connection to a fitting on the liquid line. The transducer will change its internal resistance in response to the pressures it monitors. The ATC control module provides a five volt reference signal and monitors the output voltage of the transducer on the transducer return circuit to determine refrigerant pressure. The ATC module is preprogrammed to respond to this and other sensor inputs by controlling the operation of the air conditioning compressor clutch and the auxiliary radiator cooling fan to help optimize air conditioning system performance and to protect the system components from damage. The A/C pressure transducer input to the ATC module also prevents the A/C compressor clutch from engaging when the ambient temperature is below 0.556° C (33° F) due to the pressure/temperature relationship of the refrigerant.
The A/C pressure transducer is diagnosed by performing the ATC Function Test using the DRBIII(R) scan tool. Refer to Body Diagnostic Procedures.
The A/C pressure transducer cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.