GF83.40-P-0001RT Automatic Air Conditioning (AAC), Function
GF83.40-P-0001RT Automatic Air Conditioning (AAC), Function
- with CODE (580) Automatic air conditioning
Description
The automatic air conditioning (AAC) controls the equipment to achieve the interior temperature desired by the driver and passengers. The automatic air conditioning is available immediately after starting the engine. The system operates on the basis of the humidity and temperature. The ambient air is first cooled down by adding cooled air from the evaporator, even at low outdoor temperatures and then passes through the heat exchanger where it is heated up to the desired temperature.
The automatic air conditioning regulates the interior temperature and air distribution separately for the driver and passenger seats.
The system has the following sub-functions:
Heating circuit
The coolant is heated up by the engine. When heat is required, heated coolant passes through the heating system heat exchanger where heat is transferred to the interior air. The coolant returns back to the coolant pump via the heater return.
Refrigerant circuit
The refrigerant compressor (A9) driven by the engine compresses the refrigerant vapor which is cooled down in the condenser. The refrigerant liquefies during cooling. The liquid refrigerant passes through the expansion valve into the evaporator, where it evaporates, cools down and removes the heat from the air that is flowing past, therefore cooling it down. The refrigerant compressor aspirates the refrigerant which has turned gaseous on account of the heat absorption and then compresses it yet again.
Ventilation
The ventilation system ventilates the interior of the vehicle. The air is drawn in by the blower motor (A32m1) and passes through the various air ducts to the air distribution flaps which distribute it in the vehicle interior.
Control
The electronic control for the automatic air conditioning is accomplished by various control units and temperature sensors connected with one another by the Control Area Network bus, class B (interior compartment) (CAN B), Control Area Network bus, class C (engine compartment) (CAN C) and Local Interconnect Network (LIN). The desired temperature is achieved or maintained at a constant level by cooling or heating the air.
OFF function
The air conditioning is switched off, the flap positions are maintained.
Engine residual heat utilization system
Utilization of the residual engine heat makes it possible to heat the vehicle even with the ignition "OFF". To do so the system utilizes the residual heat from the engine and guides it via the blower into the passenger compartment. The residual engine heat utilization feature is possible only when the ignition is "OFF".
Defrosting function
The defrosting function serves for keeping the windows free of fog and ice or quickly eliminating fogged windows by actuating the defroster outlet flap to the full open position and closing the footwell flaps. Function feedback is accomplished with a red LED.
A/C-OFF function
Compressor switched off, no cooling capacity. The transition cycle is accomplished to prevent the windows from fogging up. The defroster flaps are opened wider. Function feedback is accomplished with a red LED.
Recirculated air, function
Momentarily actuating the air recirculation button closes the main air flap to prevent air entering from outside. This ensures that the air circulates only in the interior compartment, keeping out unpleasant odors or pollution gases. The LED indicator comes on during operation. In the automatic mode, the control program can activate the recirculated air function.
Recirculated air convenience feature function
For easier operation, the windows and the tilting/sliding roof (SHD) (with code 414 power glass tilting/sliding roof) are closed automatically when the air recirculation switch (N22s2) is pressed for more than 1.5 s.When the air recirculation switch is actuated again, the windows and tilting/sliding roof (SR) return automatically to the previous positions.
The left vent window motor (M21/8) and right vent window motor (M21/9) are actuated via recirculated air convenience feature.
^ AUTO button, function
When the Auto button is actuated, the AUTO mode is activated and the red LED in the AUTO button comes on.In automatic mode, the blower output and air distribution are controlled automatically, in addition to temperature control.Manually resetting the blower or the air distribution, terminates the AUTO mode.When the vehicle is restarted, the function last set is activated.
The blower level is higher on the US version than on the ECE version.In the event of maximum cooling output, "MAX COOL" is additionally shown in the USA version.
