GF83.40-P-2005GM Automatic Air Conditioning Refrigerant Circuit, Function

GF83.40-P-2005GM Automatic Air Conditioning Refrigerant Circuit, Function

Component Identification:

Function requirements, general
^ Circuit 61
^ Air conditioning switched on

Automatic air conditioning refrigerant circuit, general
The interior air is cooled via the automatic air conditioning refrigerant circuit depending on the setting on the AAC [KLA] control and operating unit (N22) (without code (581) Comfort automatic air conditioning) or the comfort AAC [KLA] control and operating unit (N22/7) (with code (581) Comfort automatic air conditioning). The individual components are interconnected through lines and form a closed system.

The automatic air conditioning refrigerant circuit comprises the following subfunctions:
^ Function sequence, high-pressure side
^ Function sequence, low-pressure side

Function sequence, high-pressure side
The refrigerant compressor driven by the engine takes in the gaseous refrigerant and compresses it. The refrigerant is heated up intensely in the process. The refrigerant is then pressed through the condenser at high pressure. The compression heat is extracted from the intensely heated refrigerant and diverted via the surface of the condenser (cooling fins). The refrigerant changes state from gaseous to liquid.
The refrigerant flows from the condenser to the fluid reservoir (drier). When the refrigerant flows through the fluid reservoir, it is cleansed of any chemical and mechanical contamination to protect the downstream components.
The cleansed refrigerant is forwarded to the expansion valve and the rear air conditioning refrigerant shutoff valve (with code (582) Rear air conditioning system). The expansion valve maintains the pressure at the high-pressure side.

Function sequence, low-pressure side
The expansion valve and the rear air conditioning refrigerant shutoff valve relieve the refrigerant pressure through volume enlargement. The state of the refrigerant changes from liquid to gaseous and the evaporative (heat) loss that is released is given off into the ambient air via the evaporator surface (cooling fins). The cooled air is supplied to the vehicle interior via the blower motor (A32m1) and the rear air conditioning blower motor (M2/29) (with code (582) Rear air conditioning).

To prevent the particular evaporator from icing up, if the temperature drops below a specific value at the evaporator, the refrigerant compressor or the rear air conditioning refrigerant shutoff valve is switched off by the control and operating unit. The temperature at the evaporator and the rear air conditioning evaporator is measured by the evaporator temperature sensor and the rear air conditioning evaporator temperature sensor.