2008 MERCEDES-BENZ ML320 air conditioning

216 Controls in detail
Climate control
Rear climate control*
The control panel is located on the rear of
the front center console.
Activating rear climate control
Press buttonU.
The indicator lamp on the button
comes on. The air volume and air distri-
bution are adjusted automatically.Deactivating rear climate control
Press button´.
The indicator lamp on the button
comes on.
The cooling function switches off after
a short delay.iThe rear climate control panel is only
available if your vehicle is equipped with seat
heating* for the rear seats or Rear Audio fea-
ture* (see separate COMAND System operating
instructions).
1Left rear center air vent, adjustable
2Right rear center air vent, adjustable
3Rear climate control on
(automatic mode)
4Air distribution (directs air through
the center air vents)
5Air distribution (directs air through
the footwells and side air vents)
6Rear air conditioning off
iThe climate control must be switched on
(
page 217).
iThe temperature is adjusted according to
the settings for the front passenger side made
on the front climate control panel (
page 209).
iSwitch off the rear climate control for im-
proved cooling or heating output in the front pas-
senger compartment.
You can also switch off the rear climate control
from the front passenger compartment
(
page 217).

222 Controls in detail
3-zone automatic climate control*
Nearly all dust particles, pollutants and
odors are filtered out before outside air en-
ters the passenger compartment through
the air distribution system.
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 220).Deactivating the automatic climate
control system
Deactivating
Press button´ (page 220) until
the displaye (
page 220) is cleared.
The indicator lamp on the button
comes on.
Warning!G
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled interval. A clogged filter will
reduce the air volume to the interior and the
windows could fog up, impairing visibility
and endangering you and others. Have a
clogged filter replaced as soon as possible
at an authorized Mercedes-Benz Light Truck
Center.
Warning!G
Follow the recommended settings for heat-
ing and cooling given on the following
pages. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iIf the vehicle interior is hot, ventilate the in-
terior before driving off, see “Summer opening
feature” (
page 237). The automatic climate
control will then adjust the interior temperature
to the set value much faster.
Keep the air intake grille in front of the wind-
shield free of snow and debris.
Warning!G
When the automatic climate control system
is switched off, the outside air supply and
circulation are also switched off. Only
choose this settings for a short time. Other-
wise the windows could fog up, impairing
visibility and endangering you and others.

225 Controls in detail
3-zone automatic climate control*
Opening the side air vents
Turn thumbwheels3 andb
(
page 218) to the right.
The corresponding side air vents on the
left and right are open.
Closing the side air vents
Turn thumbwheels3 andb
(
page 218) to the left.
The corresponding side air vents on the
left and right are closed.
Adjusting air volume
Five blower speeds are available.
Press button
to decrease or
buttonQ to increase air volume
(
page 220) to the desired level.
The indicator lamp on buttonU
goes out.
The automatic mode is switched off.
The selected blower speed appears in
the displaye (
page 220).
Front defroster
You can use this setting to defrost the
windshield, such as when it is iced up. You
can also use it to defog the windshield and
door windows.
Activating
Press button| (page 220).
The indicator lamp on the button
comes on.
The automatic climate control switches to
the following functions automatically:

most efficient blower speed and
heating power, depending on outside
temperature

air flows onto the windshield and the
front door windows (side air vents must
be open)

the air conditioning compressor
switches on at outside temperatures
above approximately 41°F (5°C) for
air-drying
Adjustments
You can adjust the air volume and the tem-
perature when the front defroster is
switched on. The air flow will remain on the
windshield and front door windows.
Press button
to decrease or
buttonQ to increase air volume
(
page 220) to the desired level.
The air volume decreases/increases to
the next lower/higher blower speed
and heating switches to the tempera-
ture that was set before the front de-
froster was switched on.
The indicator lamp on button|
goes out. The indicator lamp on
button9 comes on.
or
iKeep this setting selected only until the
windshield or the side windows are clear again.


226 Controls in detail
3-zone automatic climate control*
Turn temperature control1
and/or7 (
page 220) slightly in any
direction.
Heating switches to the temperature
that was set before the front defroster
was switched on.
The indicator lamp on button|
goes out. The indicator lamp on
button9 comes on.
Deactivating
Press button| (page 220).
The indicator lamp on the button goes
out. Defrosting is turned off.
The previous settings are once again in
effect.Windshield fogged on the outside
Switch the windshield wipers on
(
page 61).
Press buttonU (page 220).
The indicator lamp on buttonU
goes out. Air volume and air
distribution are controlled separately
for each zone.
If the automatic air distribution and
air volume are switched off:
Press buttons8 andY
(
page 220).
Maximum cooling MAXCOOL
If the air distribution control as well as the
airflow volume control are set toU and
there is a high need for cooling, the
MAXCOOL function is activated.
“
MAXCOOL” appears in the front and rear
display.
This provides the fastest possible cooling
of the vehicle interior (when windows and
tilt/sliding sunroof are closed).
iThe air conditioning compressor remains on
even if the indicator lamp in button| goes
out. This helps to prevent the windshield from
fogging.
iTo switch off, you can also press
button´ orU (
page 220).
iKeep this setting selected only until the
windshield is clear again.


227 Controls in detail
3-zone automatic climate control*
Air recirculation mode
Switch to air recirculation mode to prevent
unpleasant odors from entering the vehicle
from the outside (e.g. before driving
through a tunnel). This setting cuts off the
intake of outside air and recirculates the
air in the passenger compartment.Activating
Press button: (page 220).
The indicator lamp on the button
comes on.DeactivatingPress button: (page 220).
The indicator lamp on the button
comes on.
At outside temperatures above 79°F
(26°C) the system will not automatically
switch back to outside air. A quantity of
outside air is added after approximately
30 minutes.
Warning!G
Fogged windows impair visibility,
endangering you and others. If the windows
begin to fog on the inside, switching off the
air recirculation mode immediately should
clear interior window fogging. If interior win-
dow fogging persists, make sure the air
conditioning (
page 229) is activated, or
press button|.
iThe air recirculation mode is activated auto-
matically at high outside temperatures.
The indicator lamp on button: is not lit when
the air recirculation mode is automatically
switched on.
A quantity of outside air is added after approxi-
mately 30 minutes.
If you have turned off the air conditioning
(
page 229) or the outside temperature is
below 41°F (5°C), the air recirculation mode will
not switch on automatically.
iTo cool the interior as fast as possible, the
automatic climate control automatically switch-
es to air recirculation. The indicator lamp on
button: is not lit when the system switches
to air recirculation automatically.
iThe air recirculation mode is deactivated
automatically

after 5 minutes if the outside temperature is
below approximately 41°F (5°C)

after 5 minutes if the air conditioning and
air-drying is turned off

after 30 minutes if the outside temperature
is above approximately 41°F (5°C)

229 Controls in detail
3-zone automatic climate control*
Air conditioning
The cooling function, only operational
when the engine is running, cools the vehi-
cle down to the selected interior tempera-
ture. The cooling function also
dehumidifies the air in the vehicle interior,
thereby preventing the windows from fog-
ging up.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the vehi-
cle will then no longer be cooled or dehu-
midified.
Press button9 (page 220).
The indicator lamp on the button goes
out. The cooling function switches off
after a short delay.
Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.
Press button9 again.
The indicator lamp on the button
comes on.
The air conditioning uses the refrigerant
R-134a. This refrigerant is free of CFCs
which are harmful to the ozone layer.Using driver-side settings for all tem-
perature zones
You can use the settings of the driver’s
side, such as temperature, air volume and
air distribution, for all temperature zones.
These settings only need to be made once
and the automatic climate control system
will automatically regulate the settings for
all temperature zones quickly and comfort-
ably.
iCondensation may drip out from underneath
the vehicle. This is normal and not an indication
of a malfunction.
Warning!G
If you turn off the cooling function, the
interior air is not dried. The windows can fog
up more quickly. Window fogging may
impair visibility and endanger you and
others.
!If the air conditioning cannot be turned on
again, this indicates that the air conditioning is
losing refrigerant. The compressor has turned
off.
Have the air conditioning checked at the nearest
authorized Mercedes-Benz Light Truck Center.

233 Controls in detail
3-zone automatic climate control*
Adjusting air distribution
Use the air distribution controls5 or6
to adjust the air distribution for the rear
passenger compartment.
The symbols on the controls represent the
following functions:
Adjusting manually
Press the desired air distribution con-
trol.
The indicator lamp on buttonU
goes out.Adjusting automatically
Press buttonU while the engine is
running.
The indicator lamp on the button
comes on. The air distribution is adjust-
ed automatically.
Setting the temperature
Use temperature control3 (
page 231)
to separately adjust the air temperature of
the rear passenger compartment.
You should raise or lower the temperature
setting in small increments, preferably
starting at 72°F (22°C). The automatic cli-
mate control will adjust to the set temper-
ature as fast as possible.Increasing the temperature
Turn temperature control3
(
page 231) slightly clockwise.
The rear automatic climate control will
correspondingly adjust the interior air
temperature for the rear passenger
compartment.
Decreasing the temperature
Turn temperature control3
(
page 231) slightly counterclock-
wise.
The rear automatic climate control will
correspondingly adjust the interior air
temperature for the rear passenger
compartment.
SymbolFunction
ZDirects air to the center air
vents
YDirects air to the footwells and
the side air vents
iThe rear automatic climate control will not
cool the air when the air conditioning is switched
off (
page 229).

332 Operation
Driving instructions

Adjust the mirrors (page 49) to
permit unobstructed view beyond rear
of trailer.

If the trailer has electric brakes, start
your vehicle and trailer moving slowly,
and then apply only the trailer brake
controller by hand to make sure the
brakes are working properly.

Always secure items in the trailer to
prevent load shifts while driving.

When towing a trailer, check occasion-
ally to make sure the load is secure,
and that lighting and trailer brakes (if
so equipped) are functioning properly.

Take into consideration that when tow-
ing a trailer, the handling characteris-
tics are different and less stable from
those when operating the vehicle with-
out a trailer.
It is important to avoid sudden maneu-
vers.

The vehicle and trailer combination is
heavier, and therefore is limited in ac-
celeration and climbing ability, and re-
quires longer stopping distances.
It is more prone to reacting to cross
wind gusts, and requires more sensi-
tive steering input.

If possible, do not brake abruptly, but
rather engage the brake slightly at first
to permit the trailer to activate its
brake. Then increase the braking force.

If the transmission repeatedly shifts
between gears on inclines, manually
shift to a lower gear (select 4, 3, 2 or 1)
(
page 192).
A lower gear and reduction of speed re-
duces the chance of engine overload-
ing and/or overheating.

On very steep inclines, not manageable
with automatic transmission in1,
switch on off-road driving program
(
page 253).

When going down a long hill, shift into
a lower gear and use the engine’s brak-
ing effect.
Avoid riding the brakes, thus overheat-
ing the vehicle and trailer brakes.

If the engine coolant rises to an ex-
tremely high temperature (coolant tem-
perature needle approaching the red
zone) when the air conditioning is on,
turn off the air conditioning system.
Engine coolant heat can be additionally
vented by opening the windows,
switching the climate control fan speed
to high and setting the temperature
control to the maximum hot position.
!If the trailer should begin to sway, reduce
the vehicle’s speed immediately.
In no case attempt to straighten out the tow
vehicle and trailer by increasing the speed.