Component description for automatic air conditioning control unit - GF83.40-P-3012LE
MODEL 216.3, 221.0/1 (except, 221.095/195) as of model year 2009/YoM 08
Illustrated on model 221.0
Location
The AAC [KLA] control unit is located on the front side of the air conditioner housing on the passenger side.
Task
The AAC [KLA] control unit has the following tasks:
- Control of the vehicle climate control
- Reading in of sensors and signals
- Evaluation of input factors
- Actuation of components
Control of the vehicle climate control
The AAC [KLA] control unit is the master control unit for the climate control of the vehicle interior and controls or regulates the following functions:
- Comfort automatic air conditioning (C-AAC [K-KLA]) ON/OFF
- Overall automatic system
- Regulation of interior temperature, blower output and air distribution, separately for the left and right vehicle side
- Adaptation of the footwell temperature
- Adjustment of the air flow intensity
- Defrosting
- Open/close recirculated air
- Residual engine heat utilization
- Coupling of all setting zones with driver zone
- Stationary heater climate control function (with code (228) Stationary heater)
- Remote control of rear automatic air conditioning (with model 221 with code (582) Rear air conditioning)
The comfort automatic air conditioning functions are operated via the upper control panel control unit (N72/1) or the front central operating unit (A40/9).
On model 221 with code (582) Rear air conditioning, the requests of the rear air conditioning control unit (N22/4) are sent via telematics CAN (CAN A) to the COMAND controller unit, (A40/3) via central CAN (CAN F) to the central gateway control unit (N93) and from there forwarded via interior CAN (CAN B) to the AAC [KLA] control unit.
Reading in of sensors and signals
The input factors are read in via the following connections:
- Direct line
- A/C bus (KB)
- Interior CAN
Direct line
The signals from the following components are read via a direct line:
- In-car temperature sensor (B10/4)
- Evaporator temperature sensor (B10/6)
- Left side air vent temperature sensor (B10/31)
- Right side air vent temperature sensor (B10/32)
- Left footwell temperature sensor (B10/35)
- Right footwell temperature sensor (B10/36)
- Refrigerant pressure sensor (B12)
- Left side air vent potentiometer (R41/1)
- Right side air vent potentiometer (R41/2)
- Left front center air vent potentiometer (R41/3r1)
- Right front center air vent potentiometer (R41/3r2)
Also on model 221 with code (582) Rear air conditioning:
- Left rear air conditioning heat exchanger temperature sensor (B10/9)
- Right rear air conditioning heat exchanger temperature sensor (B10/10)
- Rear air conditioning evaporator temperature sensor (B10/11)
- Left rear center air vent potentiometer (R41/4r1)
- Right rear center air vent potentiometer (R41/4r2)
AC bus
The following sensors are read in via the A/C bus:
- AAC [KLA] multifunction sensor (B31/1)
- AAC [KLA] sun sensor (4 in total) (B32/2)
- Vehicle interior humidity/temperature sensor (B82) (as of 1.9.10 with code (B03) ECO start/stop function)
Interior CAN
The signals are read in via interior CAN.
The functions resulting there from are described in the corresponding function descriptions (see the appropriate 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 affected components are then actuated.
Actuation of components
The actuation of the components takes place via the following connections:
- Direct line
- Interior CAN
- AC bus
- Climate control LIN (LIN B8)
Direct line
The following components are actuated:
- Refrigerant compressor (A9)
Also on model 221 with code (582) Rear air conditioning:
- Rear heating system feed unit (A31/1)
- Rear air conditioning electronic blower regulator (N29/2)
- Rear air conditioning refrigerant shutoff valve (Y67)
Interior CAN
The following signal is transmitted via interior CAN:
- Engine and air conditioning electric suction fan with integrated control (M4/7) request via central gateway control unit to CDI control unit (N3/9) (with diesel engine) or ME-SFI [ME] control unit (N3/10) (with gasoline engine) via chassis CAN
AC bus
The following components are actuated via A/C bus on model 221:
- Left B-pillar air distribution actuator motor (M16/33)
- Right B-pillar air distribution actuator motor (M16/34)
Climate control LIN
The following components are actuated via climate control LIN:
- Blower regulator (A32n1)
- Fresh air/air recirculation flap actuator motor (M2/5)
- Left defroster flap actuator motor (M2/8)
- Right defroster flap actuator motor (M2/9)
- Left footwell flap actuator motor (M2/10)
- Right footwell flap actuator motor (M2/11)
- Left center air flap actuator motor (M2/12)
- Right center air flap actuator motor (M2/13)
- Left side air vent flap actuator motor (M2/17)
- Right side air vent flap actuator motor (M2/18)
- Upper left blend air flap actuator motor (M2/30)
- Lower left blend air flap actuator motor (M2/31)
- Upper right blend air flap actuator motor (M2/32)
- Lower right blend air flap actuator motor (M2/33)
- Left rear center air vent actuator motor (M16/19) (on model 221 with code (582) Rear air conditioning)
- Right rear center air vent actuator motor (M16/20) (on model 221 with code (582) Rear air conditioning)
- PTC heater booster (R22/3) (with diesel engine)
| Wiring diagram for automatic air conditioning (AAC) control unit | Model 216 Specification 1 |
PE83.40-P-2101-97CAA | |
| Specification 2 | PE83.40-P-2101-97CAB | ||
| Model 221 Specification 1 |
PE83.40-P-2101-97SAA | ||
| Specification 2 | PE83.40-P-2101-97SAB |