Sprinter 2500 L5-2.7L DSL Turbo (2003)
Refrigerant Pressure Sensor / Switch: Description and Operation
A/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 Computers and Control Systems/ Body Control Module / Testing and Inspection / Procedures.
