The Refrigerant Cycle

For information regarding base refrigerant operation within the HVAC system, refer to the current Ford Web Based Technical Training courses. The diagram below shows the refrigerant system state in each component on this vehicle.

The following statements apply to this refrigerant system:

• The PCM controls the A/C clutch relay.
• The evaporator temperature sensor monitors the temperature of the evaporator core and sends a signal to the PCM. If the temperature of the evaporator core is low enough to cause the condensed water vapor to freeze, the A/C clutch is disengaged by the PCM.
• 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.

Courtesy of FORD MOTOR COMPANY