Climate Control Control Unit, Component Description - GF83.40-P-2250FH

Model 238 

up to model year 2021 

Shown On Model 238.3 

Courtesy of MERCEDES-BENZ USA

Location 

The A/C control unit is located on the front side of the A/C housing on the passenger side.

Tasks 

The A/C control unit is responsible for the following tasks:

• Read in sensors and signals 
• Evaluation of input factors 
• Actuation of components 

Read in sensors and signals 

The input factors are read in via the following connections:

• Direct line 
• Climate control LIN 1 (LIN B8-1) 
• Climate control LIN 2 (LIN B8-2) 
• A/C operating unit LIN (LIN B8-3) 
• Interior CAN (CAN B) 

Direct line 

The signals from the following components are read via direct lines:

• Evaporator temperature sensor (B10/6)
• Left side air vent air outlet temperature sensor (B10/31)
• Right side air vent air outlet temperature sensor (B10/32)
• Left footwell vent air outlet temperature sensor (B10/35)
• Right footwell vent air outlet temperature sensor (B10/36)
• Rear footwell vent air outlet temperature sensor (B10/38) (with code 581 (Automatic air conditioning))
• Refrigerant pressure sensor (B12)
• Central air distribution position recognition microswitch (S24/1) (with code 580 (Air conditioning))

Climate control LIN 1 

The signals of the air quality sensor (B31) (with CODE 581 (Automatic air conditioning)) are read in over the climate control LIN 1.

AC operation LIN 

The signals from the following components are read in via A/C operation LIN:

• Stationary heater radio remote control receiver (A6/1) (with code 228 (Stationary heater))
• Climate control operating unit (N58/1)
• Rear air conditioning operating unit (N22/4) (with code 581 (Automatic air conditioning))

Interior CAN 

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

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 
• Interior CAN 
• Climate control LIN 1 
• Climate control LIN 2 
• AC operation LIN 

Direct line 

The following components are actuated via direct lines:

• Refrigerant compressor (A9)
• Coolant circulation pump (M13/5)

Interior CAN 

The signals are sent over the interior CAN.

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

Climate control LIN 1 

The following components are actuated over the climate control LIN 1:

• With code 580 (Air conditioning system):
  • Left blend air flap actuator motor (M2/8)
  • Right blend air flap actuator motor (M2/9)
  • Fresh air/ram air/air recirculation flap actuator motor (M2/13)
  • Defroster/footwell/center air vent flap actuator motor (M2/14)
• With CODE 581 (Automatic air conditioning):
  • Left blending air flap actuator
  • Right blending air flap actuator
  • Rear blend air flap actuator motor (M2/10)
  • Left footwell/center air vent/side air vent and rear air vent flap actuator motor (M2/11)
  • Right footwell/center air vent and side air vent flap actuator motor (M2/12)
  • Fresh air/ram air/air recirculation flap actuator motor
  • Defroster/footwell/center air vent flap actuator motor
  • Left B-pillar air distribution actuator motor (M16/33)
  • Right B-pillar air distribution actuator motor (M16/34)

Climate control LIN 2 

The following components are actuated over the climate control LIN 2:

• Stationary heater control unit (A6n1) (with CODE 228 (Stationary heater))
• Blower regulator (A32n1)
• Driver side air vent ionizer (N18/9) (with CODE P21 (Air quality package))
• Left electronic booster blower (N29/10) (with code 581 (Automatic air conditioning))
• Right electronic booster blower (N29/11) (with code 581 (Automatic air conditioning))
• Perfume atomizer generator (N59) (with CODE P21 (Air quality package))
• PTC heater booster (diesel engine)

AC operation LIN 

The following components are actuated via climate control LIN:

• Climate control operating unit
• Rear air conditioning operating unit (with code 581 (Automatic air conditioning))

Wiring diagram for automatic air conditioning (AAC [KLA]) control unit

PE83.40-P-2101-97DCA