Refrigerant Pressure Sensor

Courtesy of JAGUAR CARS, INC.

The refrigerant pressure sensor provides the automatic temperature control (ATC) module with a pressure input from the high pressure side of the refrigerant system. The refrigerant pressure sensor is located in the refrigerant line between the condenser and the thermostatic expansion valve.

The automatic temperature control (ATC) module supplies a 5 V reference voltage to the refrigerant pressure sensor and receives a return signal voltage, between 0 and 5 V, related to system pressure.

The automatic temperature control (ATC) module uses the signal from the refrigerant pressure sensor to protect the refrigerant system from extremes of pressure and to calculate air conditioning (A/C) compressor load on the engine. The automatic temperature control (ATC) module also transmits the air conditioning (A/C) compressor load value to the engine control module (ECM), via the medium speed controller area network (CAN) bus, instrument cluster and high speed controller area network (CAN) bus, for use in controlling the speed of the engine cooling fan.

To protect the system from extremes of pressure, the automatic temperature control (ATC) module sets the air conditioning (A/C) compressor to the minimum flow position if the pressure:

• Decreases to 1.9 ± 0.2 bar (27.5 ± 3 lbf/in² ); the automatic temperature control (ATC) module loads the air conditioning (A/C) compressor again when the pressure increases to 2.8 ± 0.2 bar (40.5 ± 3 lbf/in² ).
• Increases to 33 ± 1 bar (479 ± 14.5 lbf/in² ); the automatic temperature control (ATC) module loads the air conditioning (A/C) compressor again when the pressure decreases to 23.5 ± 1 bar (341 ± 14.5 lbf/in² ).