Component description for automatic air conditioning control and operating unit - GF83.40-P-3000CEA

MODEL 204.0/2 as of model year 2009 without CODE 581 (Comfort automatic air conditioning) 

MODEL 204.3 

MODEL 204.9 without CODE 581 (Comfort automatic air conditioning) 

Model 204.0/2 up to 28.2.11, model 204.9 up to 31.5.12, shown without code (494) USA version 

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

Model 204.0/2 as of 1.3.11, model 204.9 as of 1.6.12, model 204.3, shown without code (494) USA version 

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 sides of vehicle
• Automatic blower control and air distribution
• Manual blower control and air distribution
• Switch automatic air conditioning (AAC [KLA]) on and off
• Defrost
• Switch on/off refrigerant compressor (A9) (without code (B09) Refrigerant compressor with magnetic clutch) or refrigerant compressor with magnetic clutch (A9/7) (with code (B09) Refrigerant compressor with magnetic clutch)
• 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:

• Button "OFF" 
• Temperature selector wheels 
• Air volume buttons 
• Air distribution button 
• "AUTO" button 
• "A/C" button 
• Rear window heater button 
• "MONO" button (model 204.0/2 up to 28.2.11, model 204.9 up to 31.5.12 without code (494) USA version) 
• "ZONE" button (model 204.0/2 as of 1.3.11, model 204.9 as of 1.6.12, model 204.3) 
• Air recirculation mode button 
• Defrosting button 
• "MAX A/C" button (with code (494) USA version) 

Button "OFF" 

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

Temperature selector wheels 

The required specified temperature for the left and right sides of the vehicle can be set by turning the corresponding temperature selector wheel. The selected specified temperature is displayed through the light-emitting diodes (LED) of each 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 controlled 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 (model 204.0/2 up to 28.2.11, model 204.9 up to 31.5.12 without code (494) USA version) 

Pressing the "MONO" button accepts the values configured on the driver-side for temperature for the passenger side.

"ZONE" button (model 204.0/2 as of 1.3.11, model 204.9 as of 1.6.12, model 204.3) 

Pressing the "ZONE" button accepts the values configured on the driver-side for temperature 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) Power 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 comfort air recirculation closing procedure is described in the separate "Convenience feature (CF [KFB])" function description.

Defrosting button 

Pressing the defrosting button sets the temperature to "maximum" and distributes the air flow to the defroster vents. The fresh air/recirculated air 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) 

Pressing the "MAX A/C" button causes the blower output to be raised to 100 % and the temperature set to "maximum cold".

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 direct lines:

• 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 204.3/9)

Climate control LIN 

The signals from the interior humidity/temperature sensor (B82) (as of 1.12.09 and with code (B03) ECO start-stop function) can be read in over the climate control LIN.

Interior CAN 

The following signals are read in over the interior CAN:

• Vehicle speed, provided by instrument cluster (A1)
• Status of voice control system (VCS [SBS]), provided by the radio with auto pilot system (A2/56) (with code (511) Audio 50 APS with DVD changer) or by the 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))
• Provided by front SAM control unit with fuse and relay module (N10/1):
  • Coolant temperature from coolant temperature sensor (B11/4)
  • Refrigerant pressure from refrigerant pressure sensor (B12)
  • Outside temperature from outside temperature sensor (B14)
  • Engine speed
• Interior temperature from interior temperature sensor with integrated fan (N70b1) (model 204.0/2 with code (414) Power glass tilting/sliding roof), provided by overhead control panel control unit (N70)
• Status of circuit 15, provided by electronic ignition lock control unit (N73)

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 

The actuation of the components takes place via the following connections:

• Direct line 
• Climate control LIN 
• Interior CAN 

Direct line 

The blower regulator (A32n1) is actuated via a direct line.

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 642.9 up to 31.5.13, 646.8, 651.9 or with engine 274 with code (824) Additional parts for cold countries)

Interior CAN 

The signals are sent by the automatic air conditioning control and operating unit via interior CAN.

The functions that use these signals are described in the individual function descriptions (see block diagram or function schematic).

	Wiring diagram for automatic air conditioning (AAC) control unit	MODEL 204.0/2 as of model year 2009 without CODE 581 (Comfort automatic air conditioning) Specification 1, connector 1MODEL 204.3Specification 1, connector 1MODEL 204.9 without CODE 581 (Comfort automatic air conditioning) Specification 1, connector 1	PE83.40-P-2101-97FAA
	Wiring diagram for automatic air conditioning (AAC) control unit	MODEL 204.0/2 as of model year 2009 without CODE 581 (Comfort automatic air conditioning) Specification 2, connectors 2 and 3MODEL 204.3Specification 2, connectors 2 and 3MODEL 204.9 without CODE 581 (Comfort automatic air conditioning) Specification 2, connectors 2 and 3	PE83.40-P-2101-97FAD