Fusion AWD L4-2.3L (2008)
Expansion Block/Orifice Tube: Description and Operation
Thermostatic Expansion Valve
The thermostatic expansion valve (TXV) is located between the evaporator core lines and the thermostatic expansion valve manifold and tube
assembly at the rear of the engine compartment. The TXV provides a restriction to the flow of refrigerant from the high-pressure side of the refrigerant
system and separates the low-pressure and high-pressure sides of the refrigerant system. Refrigerant entering and exiting the evaporator core passes
through the TXV through 2 separate flow paths. An internal temperature sensing bulb senses the temperature of the refrigerant flowing out of the
evaporator core and adjusts an internal pin-type valve to meter the refrigerant flow into the evaporator core. The internal pin-type valve decreases the
amount of refrigerant entering the evaporator core at lower temperatures and increases the amount of refrigerant entering the evaporator core at higher
temperatures.
A/C Pressure Transducer
The A/C pressure transducer monitors the compressor discharge pressure and communicates with the PCM. The PCM will interrupt A/C compressor
operation in the event that the A/C pressure transducer indicates high system discharge pressures. It is also used to sense low charge conditions. If the
pressure is below a predetermined value for a given ambient temperature, the PCM will not allow the clutch to engage.
