The Refrigerant Cycle: Notes

For information regarding basic HVAC system refrigerant operation, refer to the current Ford Web Based Technical Training courses. The following diagram shows the refrigerant system state in each component.

The following are characteristics of the ATC system:

• The PCM controls the A/C clutch SMART FETA/C clutch control in the BCMC also known as the BJB.
• The evaporator temperature sensor monitors the temperature of the air that has passed through the evaporator core and sends a signal to the PCM. If the temperature of the evaporator core discharge air is low enough to cause the condensed water vapor to freeze, the PCM disengages the SMART FETA/C clutch control in the BCMC also known as the BJB.
• The line pressure is monitored so that A/C compressor operation is interrupted if the system pressure becomes too high or too low.
• The A/C compressor relief valve opens and vents refrigerant to relieve unusually high system pressure.