Ventilation system function

N83.10-2053-05

Shown with code (HZ7) Regulated air conditioning (Tempmatic) in passenger compartment

4 Adjustable left center nozzle

5 Thumb wheel for air supply for air vents in left and right head area and rear compartment

5/1 Air vents for left head area and rear compartment

5/2 Air vents for right head area and rear compartment

6 Adjustable right center nozzle

7 Thumb wheel for right side air outlet

8 Adjustable right side air outlet

9 Defroster vent for right side window

10 Thumb wheel for left center nozzle

11 Thumb wheel for right center nozzle

S98 Air conditioning operating module

S98s8 Air distribution switch

S98s9 "AUTO" button

S98s10 Temperature control button

S98s11 Blower control button

S98s12 EC/residual heat system and rear air conditioning button

S98s13 Air dehumidification mode or defrosting and air recirculation mode button

The vents supply air to the vehicle interior (air circulation) and additionally ensure the following:

 the windshield and windows are kept defogged

 there is a good oxygen supply to occupants

 constant and pleasant temperatures are quickly achieved in the vehicle interior

The ventilation control can be switched to automatic mode by pressing the "AUTO" button (S98s9) and back again to manual mode by pressing the button again.

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In automatic mode, the blower output of the blower motor (M2) and the position of the air distribution flap are automatically controlled via the air distribution actuator motor (M16/22) depending on the outside temperature, the temperature in the vehicle interior, the direct solar radiation and the specified temperature set.

In manual mode, the blower output of the blower motor (M2) is increased or decreased via the blower control button (S98s11) and the position of the air distribution flap is adjusted via the air distribution switch (S98s8).

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Aeration can occur using one of the following 3 modes:

 Fresh air mode

 Air recirculation mode

 Defrost mode

 Air recirculation mode is terminated after 10 to 30 min. dependent upon the outside temperature. Next, the system automatically switches back to fresh air mode.

The selection of the fresh air or air recirculation mode is made by pressing the air dehumidification mode or defrosting and air recirculation mode button (S98s13) in the lower subfield.

The blower control button (S98s11) and the air distribution switch (S98s8) integrated in the air conditioning operating module (S98) are used to control the rate of circulation and the distribution of the fresh or recirculated air. The rate of circulation is controlled with the aid of the blower motor (M2).

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The blower control button (S98s11) can be used to adjust the power output of the blower motor (M2) via the blower regulator (M2n1) to the following 8 stages:

 STAGE 0

 STAGE 1

 STAGE 2

 STAGE 3

 STAGE 4

 STAGE 5

 STAGE 6

 STAGE 7

Distribution of the suctioned fresh or recirculated air can be controlled with the aid of the air distribution flap via the air distribution switch (S98s8). The distribution of the suctioned fresh or recirculated air is possible in the following positions:

 Defroster vents (12:00 o'clock position)

 Defroster vents and footwell vents (3 o'clock position)

 Footwell vents (6 o'clock position)

 Dash support vents (9 o'clock position)

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 Intermediate positions are also possible in addition to the listed positions, e.g., when the air distribution switch (S98s8) is in between the defroster vent (12 o'clock position) and the defroster vent and footwell vent position (3 o'clock position).

The suctioned fresh or recirculated air in the vehicle interior is then distributed, dependent upon the setting via the air distribution switch (S98s8), through the following air outlets:

 Defroster vent for left side window

 Adjustable left side air outlet

 Adjustable left center nozzle (4)

 Air vents for left head area and rear compartment (5/1)

 Air vents for right head area and rear compartment (5/2)

 Adjustable right center nozzle (6)

 Adjustable right side air outlet (8)

 Defroster vent for right side window (9)

 Left footwell vents

 Right footwell vents

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The exit of the fresh or recirculated air is also dependent upon the position of the following thumb wheels:

 Thumb wheel for left side air outlet

 Thumb wheel for air supply for air vents in left and right head area and rear compartment (5)

 Thumb wheel for right side air outlet (7)

 Thumb wheel for left center nozzle (10)

 Thumb wheel for right center nozzle (11)

Fresh air mode

Fresh air mode is selected, if the fresh air or air recirculation mode display is not shown on the display of the air conditioning operating module (S98). During fresh air mode, the fresh air/air recirculation flap actuator motor (M16/21) keeps the two fresh air and air recirculation flaps open in the fresh air position. In this position, the ambient air is drawn in into the A/C housing with the aid of the blower motor (M2) via the air duct above the hood, the particulate filter (on vehicles with code (HF2) Pollen filter) and via the two fresh air and air recirculation flaps.

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Dependent upon the adjustment via the blower control button (S98s11), the temperature control button (S98s10), and the air distribution switch (S98s8), the fresh air reaches the vehicle interior through the air ducts and the air outlets. The fresh air escapes through the two vent flaps from the vehicle, which are attached to the left rear side wall and to the right rear side wall.

Recirculation mode

Air recirculation mode is selected, if the fresh air or air recirculation mode indication is shown on the display of the air conditioning operating module (S98). During air recirculation mode, the fresh air/air recirculation flap actuator motor (M16/21) keeps the two fresh air and air recirculation flaps closed in the recirculated air position. In this position, the recirculated air is drawn in from the vehicle interior into the A/C housing with the aid of the blower motor (M2).

Dependent upon the adjustment via the blower control button (S98s11), the temperature control button (S98s10), and the air distribution switch (S98s8), the recirculated air reaches the vehicle interior through the air ducts and the air outlets.

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 If the outside temperature is above 20 °C, the system automatically switches to fresh air mode after 30 min.

If the outside temperature is below 20 °C, the system automatically switches to fresh air mode after 10 min.

Defrost mode

When the air dehumidification mode or defrosting and air recirculation mode button (S98s13) is pressed once, defrost mode is switched on in the upper subfield. This is indicated by showing the defrost mode on the display of the air conditioning operating module (S98). The defrost mode is used to defrost the windshield. In defrost mode, the air conditioning operating module (S98) regulates the blower output to stage 7 and the air distribution flap to the defroster nozzle position (12:00 o'clock position). At the same time, the air conditioning operating module (S98) controls the temperature in the vehicle interior via the blending air and shutoff flap to 28 °C.

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Defrost mode is switched off when the air dehumidification mode or defrosting and air recirculation mode button (S98s13) in the upper subfield is pressed again.

The defrost mode display on the display of the air conditioning operating module (S98) goes out.

Reheat mode is activated when the air dehumidification mode or defrosting and air recirculation mode button (S98s13) in the upper subfield is pressed again. This is indicated by showing the reheat mode on the display of the air conditioning operating module (S98). To switch off reheat mode, the air dehumidification mode or defrosting and air recirculation mode button (S98s13) in the upper subfield has to be pressed again. The reheat mode display on the display of the air conditioning operating module (S98) goes out.

Convenience feature via the air dehumidification mode or defrosting and air recirculation mode button (S98s13)

If the air dehumidification mode or defrosting and air recirculation mode button (S98s13) in the lower subfield is pressed for more than 1.5 s, the comfort closing function is activated. In doing so, the following windows and tilting/sliding roofs are closed and their particular position before they are closed is stored:

 Side windows of driver and front passenger door

 Rear tilting/sliding roof (SHD) (M12/1), with code (D24) Glass tilting/sliding roof in passenger compartment

 Tilting/sliding roof (SHD) (M12), with code (D27) Glass tilting/sliding roof, driver compartment

When the air dehumidification mode or defrosting and air recirculation mode button (S98s13) in the lower subfield is pressed for more than 1.5 s again, the listed windows and tilting/sliding roofs are opened again to the position that was previously saved.