Air distribution IHKA RR

Air distribution is automatic. In principle, the inside of the vehicle can be ventilated by means of the following air vents:

• Air vent for defrosting the windshield glass
  
• Spherical vent, front left, outside and center
  
• Spherical vent, front right, outside and center
  
• Knee vent, front left and right
  
• Footwell vent, front left and right
  
• Eyeball vent, rear middle left
  
• Eyeball vent, rear middle right
  
• Footwell vent, rear left and right
  

Influences on the air distribution

The automatic air distribution is influenced by the following factors:

Position of the slide switch at the spherical vents

The potentiometers for calibration of the air flaps behind the spherical vents are connected by pivot levers with the slide switches. The following relationship exists between the position of the slide switch, the signal voltage at the potentiometer and the flap position:

• Slide switch pulled to limit position:
  
  • Signal voltage 3.3 ... 3.5 V
    
  • Flap is fully opened
    
• Slide switch pressed to limit position:
  
  • Signal voltage 1.4 ... 1.8 V
    
  • The flap is fully closed
    
• Slide switch in intermediate range:
  
  • 1.8 V < signal voltage < 3.3 V
    
  • Flap position linear to voltage
    
• Exception: If the ventilation flap of a knee vent is opened, the ventilation flap at the front center spherical vent of the corresponding page is cut to 50% in heating mode and closed in cooling mode. In the transition between the heating and cooling modes, linear characteristics in relation to the adjusting value appear.
  
• Influence on the position of the ventilation flaps of the indirect air vents
  The ventilation flaps on the indirect air vents react as follows to the position of the slide switch for the air vents positioned in the center of the dashboard:
  
  • Slide switch pulled to limit position:
    
    • indirect air vent closed
      
  • Slide switch pressed to limit position:
    
    • indirect air vent opened
      
  • Slide switch (and thus potentiometer setting) to 50%:
    
    • direct and indirect air vents opened 100%
      
  • Slide switch in intermediate range:
    
    • direct and indirect ventilation flaps are linear
      

Position of the slide switch for the knee vent

When the slide switch is pushed in, the Hall signal is active and the ventilation flap of the knee vent is closed. With the slide switch pulled out, the Hall signal is inactive and the ventilation flap opened.

Setting the stage for the automatic window defrosting/defogging

OFF position: In the OFF position, the connected defrosting flaps are closed.

Position LOW, MED and HIGH: In the positions LOW, MED and HIGH, the connected defrosting flaps are positioned according to characteristic curves saved in the control module.

Exception: in order to avoid starting condensation, the defrosting flaps remain closed for 12 seconds after the engine is started.

The blower output is raised by a corresponding value so as not to influence the air volume distribution at the spherical and knee vents and to provide the driver with acoustic feedback. This fixed blower speed increase is saved for all three positions in the control module.

DEF position: In the DEF position, the connected defrosting flaps are opened 100%. The output of the main blower is raised by a fixed value in saved in the control module.