Refrigerant Pressure Sensor

Refrigerant Pressure Sensor

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

To protect the system from extremes of pressure, the ATC (automatic temperature control) module disengages the A/C (air conditioning) compressor clutch if the pressure:
^ Decreases to 1.9 ± 0.2 bar (27.5 ± 3 lbf/sq.in): the ATC (automatic temperature control) module engages the A/C (air conditioning) compressor clutch again when pressure increases to 2.8 ± 0.2 bar (40.5 ± 3 lbf/sq.in ).
^ Increases to 33 ± 1 bar (479 ± 14.5 lbf/sq.in): the ATC (automatic temperature control) module engages the A/C (air conditioning) compressor clutch again when pressure decreases to 23.5 ± 1 bar (341 ± 14.5 lbf/sq.in).