GF83.40-P-3000CEA Component Description For Automatic Air Conditioning Control and Operating Unit

GF83.40-P-3000CEA Component Description For Automatic Air Conditioning Control And Operating Unit
- except CODE (581) Comfort automatic air conditioning

Component Identification:

Location
The automatic air conditioning control and operating unit is located in the instrument panel.

Task
The automatic air conditioning control and operating unit performs the following tasks:
^ Operation of the vehicle's climate control
^ Reading in of sensors, pickups and signals
^ Evaluation of input factors
^ Actuation of components

Operation of the vehicle's climate control
The automatic air conditioning control unit is the master control unit for the climate control of the vehicle interior and controls or regulates the following functions:
- Interior temperature selection separated for the left and right side of vehicle
- Automatic blower control and air distribution

On vehicles with code (494) USA version, the "MAX A/C" button is installed instead of the "MONO" button.

- Manual blower control and air distribution
- Switch automatic air conditioning (AAC [KLA]) on and off
- Defrost function
- Switching the A/C compressor (A9) on and off
- Mono mode (without code (494) USA version)
- Recirculated air mode
- Maximum cooling output (with code (494) USA version)
- Control of the rear window heater (R1)

The functions are operated using the following controls on the automatic air conditioning control and operating unit:
^ "OFF" button
^ Temperature selector wheels
^ Air volume buttons
^ Air distribution button
^ "AUTO" button
^ "A/C" button
^ Rear window heater button
^ "MONO" button (except code (494) USA version)
^ Air recirculation mode button
^ Defrosting button
^ "MAX A/C" button (with code (494) USA version)

"OFF" button
The AAC [KLA] can be switched off completely or switched back on by pressing the "OFF" button.

Temperature selector wheels
The desired specified temperature for the left and right sides of the vehicle can be set by turning the temperature selector wheel. The selected specified temperature is displayed via light-emitting diodes (LED) of the temperature selector wheel. With the temperature set to maximum, "HI" appears in the display; with the temperature set to minimum, "LO" appears in the display.

Air volume buttons
Pressing the respective air volume button enables the air volume to be manually selected.
The selected setting is shown on the display.

Air distribution button
The air distribution button can be used to manually adjust the air distribution. The selected air distribution setting is shown on the display.

"AUTO" button
The air volume and the air distribution are regulated automatically when the AUTO button is pressed. If automatic mode is activated, the LED in the "AUTO" button lights up.

Manually adjust the air volume or air distribution to deactivate automatic mode.

"A/C" button
Pressing the A/C button switches the refrigerant compressor on or off. All other functions are retained. The LED in the "A/C" button lights up when the refrigerant compressor is switched on.

Rear window heater button
The rear window heater is switched on when the rear window heater button is pressed. The LED in the rear window heater button lights up during operation.

"MONO" button (except code (494) USA version)
When the "MONO" button is pressed, the values for the temperature set on the driver side are adopted for the passenger side.

Air recirculation mode button
Briefly operating the air recirculation mode button prevents air entering from outside. The LED in the air recirculation mode button lights up during operation.

If pressed longer, the comfort air recirculation closing is activated. The side windows and the tilting/sliding roof (with code (414) Electric glass tilting/sliding roof) or the panoramic sliding sunroof (with code (413) Panoramic glass sunroof with top sliding sunroof) are then closed or opened as a consequence.

The comfort recirculation closing function does not exist on vehicles with code (460) Canada version or code (494) USA version.

The detailed convenience recirculation closing procedure is described in the convenience feature function (KFB).

Defrosting button
Pressing the defrosting button sets the temperature to "maximum" and distributes the air flow to the defroster vents. The air recirculation flap remains open. All other flaps of the air conditioner housing are closed.

The blower output is regulated to match the coolant temperature. The LED in the defrosting button lights up during operation.

"MAX A/C" button (with code (494) USA version)
Press the "MAX A/C" button to raise the basic ventilation to the maximum value P = 100 %. "MAX COOL" is shown on the display.

Reading in of sensors, pickups and signals
The input factors are read in via the following connections:
- Direct line
- Climate control LIN (LIN B8)
- Interior CAN (CAN B)

Direct line
The signals from the following components are read via a direct line:
- Interior temperature sensor (B10/4)
- Evaporator temperature sensor (B10/6)
- Sun sensor (B32/3)
- Interior temperature sensor with integrated fan (N70/3b1) (model 204.0/2 without code (414) Power glass tilting/ sliding roof, model 204.9)

Climate control LIN
The signals of the following sensors are read in via climate control LIN:
- Interior humidity/temperature sensor (B82) (as of YoM 09/2 to 1.12.09)

Interior CAN
The following signals are read in over the interior CAN:
- Provided by instrument cluster (A1):
- Vehicle speed
- Provided by radio with auto pilot system (A2/56) (with code (511) Audio 50 APS with DVD changer) or by COMAND controller unit (A40/3) (with code (512) COMAND APS with DVD changer or with code (527) COMAND APS with single DVD drive (with navigation)):
- Status of voice control system (VCS)
- Provided by front SAM control unit with fuse and relay module (N10/1):
- Coolant temperature sensor (B11/4)
- Refrigerant pressure sensor (B12)
- Outside temperature sensor (B14)
- Engine speed
- Provided by the overhead control panel control unit (N70):
- Interior temperature sensor with integrated fan (N70b1) (model 204.0/2 with code (414) Power glass tilting/sliding roof)
- Provided by electronic ignition lock control unit (N73):
- Circuit 15 status

Evaluation of input factors
The input factors that have been read in are evaluated by the integrated microprocessor and the relevant components are then actuated.

Actuation of components
Actuation of the components takes place via the following connections:
^ Direct line
^ Climate control LIN
^ Interior CAN

Direct line
The following component is actuated via a direct line:
- Blower regulator (A32n1)

Climate control LIN
The following components are actuated via climate control LIN:
- Fresh air/recirculated air flap actuator motor (M2/5)
- Left blend air flap actuator motor (M2/6)
- Right blend air flap actuator motor (M2/7)
- Defroster flap actuator motor (M2/16)
- Air distribution flap actuator motor (M16/22)
- PTC heater booster (R22/3) (with engine 271.8, 646.8, 642.9 or 651.9)

Interior CAN
The following components are actuated with the interior CAN:
- From the rear SAM control unit with fuse and relay module:
- Refrigerant compressor control valve
- AC compressor magnetic clutch (A9y1) (model 204.002/202)
- From the left front door control unit (N69/1):
- Left front door power window motor (M10/3)
- From the right front door control unit (N69/2):
- Right front door power window motor (M10/4)
- From the left rear door control unit (N69/3):
- Left rear door power window motor (M10/5)
- From the right rear door control unit (N69/4):
- Right rear door power window motor (M10/6)
- From the overhead control panel control unit:
- Tilting/sliding roof motor (M12m1) (with code (414) Electric glass tilting/sliding roof)
- From the panoramic sliding sunroof control module (A98) (with code (413) Panoramic glass sunroof with top sliding sunroof):
- Panoramic sliding sunroof motor (A98m1)