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

Model 453.091/391/491 

Location 

The climate control unit is located on the left side under the instrument panel.

Task 

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 
• Interior CAN (CAN B) 
• A/C operating unit LiN (LiN B8-3) 

Direct line 

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

• Evaporator temperature sensor (B10/6) (with code I01 (Automatic air conditioning))
• Air quality sensor (B31) (Country-specific with code I01 (Automatic air conditioning))
• Vehicle interior humidity and temperature sensor (B82)
• Left front seat heater switch (S51/1) (with code U14 (A/C package))
• Right front seat heater switch (S51/2) (with code U14 (A/C package))
• Left rear seat heater switch (S51/3) (model 453.0 with code U14 (A/C package))
• Right rear seat heater switch (S51/4) (model 453.0 with code U14 (A/C package))

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 the appropriate block diagram or function schematic). The following signals on the interior CAN are read in, for example, by the climate control unit:

• Outside temperature from instrument cluster
• Status of soft top from soft top control contol unit (A52n1)
• Vehicle speed from Electronic Stability Program control unit (N30/4)
• Status of solar radiation from driver-side SAM control unit (N10/11) (with code I01 (Automatic air conditioning))
• Status of windshield wiper from driver-side SAM control unit
• Status of central locking from center SAM control unit (N10/10)
• Status defrosting from center SAM control unit
• Requests or signals from electric drive control unit (N127):
  • Drivetrain operational status
  • Energy economy request from energy management
  • Available energy status
  • Battery capacity status
  • Available charging capacity status
  • Pre-entry climate control request approval in CAN message "PreHeatingActivation"
  • Status and consumption of high voltage PTC heater (N33/5)
  • Request for actuation of electric expansion valve (battery) (in heat exchanger for cooling system of high-voltage battery cooling circuit (with code V03 (Battery cooling system)))
  • Status of electric refrigerant compressor (A9/6) (with code I01 (Automatic air conditioning))
  • Status of refrigerant pressure (with code I01 (Automatic air conditioning))

AC operation LIN 

The climate control unit reads in the signals from the climate control operating unit (N20) via the climate control LIN.

Evaluation of input factors 

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

Actuation of components 

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

• Direct line 
• Interior CAN 

Direct line 

The following components are actuated:

• Steering wheel heater relay (F2k7) (with code U14 (A/C package))
• Fresh air/recirculated air flap actuator motor (M2/5)
• Blend air flap actuator motor (M2/14)
• Footwell flap actuator motor (M2/15)
• Front passenger seat heater control unit (N25/4) (with code U14 (A/C package))
• Driver seat heater control unit (N25/5) (with code U14 (A/C package))
• Blower regulator (N76/1)
• Electric expansion valve (vehicle interior) (Y19/1) (with code I01 (Automatic air conditioning))
• Electric expansion valve (battery) (Y19/3) (with code V03 (Battery cooling system))

Interior CAN 

The signals are sent over the interior CAN by way of example.

• Request for rear window and mirror heater to center SAM control unit
• Request for defrosting to center SAM control unit
• Display settings over audio gateway control unit and telematics CAN (CAN A) to Smart Radio Multimedia Navigator (A40/3)
• Status of switched-on climate control to center SAM control unit and telematics services communications module (N112/2)
• Fan status to center SAM control unit
• Request or signals to electric drive control unit:
  • Request and target engine speed of electric refrigerant compressor (with code I01 (Automatic air conditioning))
  • Pre-entry climate control query request in CAN message "PreHeatingRequest"
  • Setting evaporator specified temperature (with code I01 (Automatic air conditioning))
  • Actual temperature for evaporator (with code I01 (Automatic air conditioning))
  • Fan motor (M4/7) speed request (with code I01 (Automatic air conditioning))
  • High voltage PTC heater request
  • Status of electric expansion valve (battery) (with code V03 (Battery cooling system))

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

Wiring diagram of air conditioning

PE83.30-P-2000-97BEA