GF83.10-P-2000LE Ventilation System, Function
GF83.10-P-2000LE Ventilation System, Function
General function requirements
^ Circuit 15 On
The circuit status of circuit 15 is provided by the EIS [EZS] control unit (N73) on the interior CAN (CAN-B).
Ventilation, general
The ventilation system prevents windows from misting up, supplies air to the vehicle occupants, and ensures that uniform and pleasant temperatures in the vehicle interior are reached quickly. When the fresh air/air recirculation flap is adjusted correspondingly, fresh air is supplied to the air conditioner housing via the air inlet. Depending on the current settings at the upper control panel control unit (N72/1), at the front central operating unit (A40/9) or at the rear air conditioning control unit (N22/4) (model 221 with code (582) Rear air conditioning), the air is routed through air ducts and air outlets into the vehicle interior.
When circuit 15 is off and one of the doors is opened, the fresh air and air recirculation flap is moved to the 40 % position for t = 2 min by the fresh air and air recirculation flap actuator motor (M2/5). This achieves a significant reduction in the door closing forces.
Fogging of the windows is prevented by closing the defroster vent flaps as well as the fresh air/air recirculation flap and by opening the footwell flaps t = 2 min after switching off circuit 15. After starting the engine, the defroster vent flaps and the footwell flaps remain in this fixed position for t = 30 s. The fresh air/air recirculation flap can be adjusted immediately. After that, all adjustments are possible again.
The ventilation function consists of the following subfunctions:
^ AC component actuation function sequence
^ Fresh air mode function sequence
^ Air recirculation mode function sequence
AC component actuation function sequence
The AC component actuation function sequence comprises the following subfunctions:
^ Function sequence, actuation of the blower motor (A32m1) and the rear blower motor (M2/1) (model 221 with code 582) Rear air conditioning)
^ Function sequence, actuation of the air ducting flaps
Function sequence, actuation of the blower motor and rear blower motor
In accordance with the position of the fresh air/air recirculation flap, the interior air is circulated or fresh air is supplied by actuating the blower motor and the rear blower motor.
The blower motor is actuated by means of the blower regulator (A32n1), the rear blower motor is actuated by means of the rear air conditioning electronic blower regulator (N29/2) (model 221 with code (582) Rear air conditioning), in each case with the power regulated within a range of P = 0 to 100%.
The blower regulator is actuated via the climate control LIN LIN B8) and the rear air conditioning electronic blower regulator is actuated directly by the AAC [KLA] control unit (N22/1). Depending on the control voltage, the blower regulators regulate the operating voltage for the blower motor, from U = 0 to 12.5 V and for the rear blower motor, from U = 0 to 12 V and thus the rotational speed of the particular blower motor from 0 up to 100 %.
When the voice control system is active, the blower output is limited by the blower regulator. For this purpose, the COMAND control unit (A40/3) sends the status of the voice control system via the central CAN (CAN F) to the central gateway control unit (N93) and from there, via the interior CAN to the AAC control unit. This then limits the blower output.
Air ducting flaps actuation function sequence
The air distribution in the vehicle interior is controlled by adjusting the air ducting flaps in the air conditioner housing.
The following components are actuated by the AAC [KLA] control unit via the climate control LIN:
- for fresh air/recirculated air control:
- Fresh air/air recirculation flap actuator motor
- for temperature control:
- 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)
- for ventilation control
- 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)
- Left rear center air vent actuator motor (M16/19)
(model 221 with code (582)Rear air conditioning)
- Right rear center air vent actuator motor (M16/20)
(model 221 with code (582) Rear air conditioning)
- Left B-pillar air distribution actuator motor (M16/33)
(model 221)
- Right B-pillar air distribution actuator motor (M16/34) (model 221)
Fresh air mode function sequence
In fresh air mode, the fresh air/air recirculation flap is open and fresh air is delivered into the vehicle interior through the air conditioning housing.
Air recirculation mode function sequence
The air recirculation mode function sequence comprises the following subfunctions:
^ Function sequence, air recirculation mode via air recirculation button (N72/1s37)
^ Pollutant-controlled air recirculation mode function sequence
(with code (581) Comfort automatic air conditioning)
Function sequence, air recirculation mode via the air recirculation button
Pressing the air recirculation button on the upper control panel control unit for t < 1.5 s closes the fresh air/air recirculation flap and thus prevents the supply of outside air. The air only circulates in the vehicle interior and unpleasant odors and harmful gases are kept out. The LED in the air recirculation button comes on.
Pressing the air recirculation button for t > 1.5 s activates comfort recirculation closing. As a result, the windows and the tilting/sliding roof (SR) (model 216 or model 221 with code (414) Power glass tilting/sliding roof) or the panoramic sliding sunroof (model 221.1 with code (413) Panoramic glass sunroof with top sliding sunroof) are closed.
When the air recirculation button is pressed again for t > 1.5 s, the windows and the tilting/sliding roof or the panoramic sliding sunroof return to the previous positions.
On vehicles with code (460) Canada version and code (494) USA version, comfort recirculation closing is not possible.
The detailed procedure of the comfort recirculation closing function is described in the comfort feature function (KFB).
Additional function requirements for pollutant-controlled air recirculation mode
^ Refrigerant compressor (A9) switched on
^ Defrost mode not active
^ Outside temperature T > 5 °C
Pollutant-controlled air recirculation mode function sequence
The pollutant concentration in the outside air is measured by the AAC [KLA] multifunction sensor (B31/1). The data of the AAC multifunction sensor are read in by the AAC [KLA] control unit via the AC bus (ACB).
Starting from a certain increase in the pollutant concentration, the fresh air/air recirculation flap is automatically set to the air recirculation position by the AAC [KLA] control unit. Outside air supply is prevented and only the inside air is recirculated.
