Page 212 of 539

211 Controls in detail
Climate control
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.
Air conditioning
The air conditioning is operational while
the engine is running and cools the interior
air to the temperature set by the operator.
In addition, the air conditioning dehumidi-
fies the interior air at outside temperatures
above 41°F (5° C) and helps prevent
window fogging.Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the climate
control system. The air in the vehicle will
then no longer be cooled or dehumidified.
Press button2 (
page 204).
The indicator lamp on the button2
goes out.
iThe air recirculation mode is
deactivated automatically
after five minutes if the outside
temperature is below
approximately 41°F (5°C)
after five minutes if the air condi-
tioning and air-drying is turned off
after 30 minutes if the outside
temperature is above
approximately 41°F (5°C)
iCondensation may drip out from under-
neath 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 im-
pair visibility and endanger you and others.
Page 213 of 539

212 Controls in detailClimate controlActivating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.
Press button2 again.
The indicator lamp on button2
comes on.
The air conditioning uses the refrigerant
R134a. This refrigerant is free of CFCs
which are harmful to the ozone layer.
Residual heat and ventilation
With the engine switched off, it is possible
to continue to heat or ventilate the interior
for up to 30 minutes. This feature makes
use of the residual heat produced by the
engine.Activating
Turn the SmartKey in the starter switch
to position0or1, or remove it from
the starter switch.
Press buttonT (
page 204).
The indicator lamp on buttonT
comes on.
Deactivating
Press buttonT (
page 204).
The indicator lamp on buttonT
goes out.
!If the air conditioning cannot be turned
on again, this indicates that the air con-
ditioning is losing refrigerant. The com-
pressor has turned itself off.
Have the air conditioning checked at
the nearest authorized Mercedes-Benz
Light Truck Center.
iHow long the system will provide heat-
ing depends on the coolant tempera-
ture and the battery voltage.
Regardless of the temperature and air
volume set on the climate control panel
an interior temperature is aimed at by
72°F (22°C) and the blower runs for
the protection of the battery on low
stage.
Page 214 of 539
213 Controls in detail
Climate control
Rear air conditioningRear climate control panel
1Left rear center air vent, adjustable
2Right rear center air vent, adjustable
3Air distribution and air volume
(automatic, manual)
4Directs air through the center air vents
5Directs air through the footwells and
both center air vents
6Rear air conditioning on/off
Activating rear air conditioning
Press buttonU.
The indicator lamp on buttonU
comes on. The temperature, air volume
and air distribution are adjusted
automatically.
iThe residual heat is automatically
turned off:
when the ignition is switched on
after about 30 minutes
if the coolant temperature is too
low
if the battery voltage drops
Page 215 of 539
214 Controls in detailClimate controlDeactivating rear air conditioning
For an improved cooling or heating output
in the front passenger compartment, you
can switch off the rear passenger compart-
ment ventilation.
Press button´.
The indicator lamp on button´
goes out.
The cooling function switches off after
a short delay.Adjusting air distribution
Use the air distribution controls4 or5
to adjust the air distribution for the rear
passenger compartment.
The following symbols are found on the
controls:Adjusting manually
Press the desired air distribution con-
trol.
The indicator lamp in the Ubutton
goes out.
Adjusting automatically
Press buttonU (
page 213).
The indicator lamp in the Ubutton
illuminates. The air distribution is ad-
justed automatically.
Symbol
Function
Z
Directs air to the center air
vents
Y
Directs air to the footwells and
the side air vents
Page 219 of 539
218 Controls in detail3-zone automatic climate control*1
Temperature control, left
2
Air distribution and air volume
(automatic, manual)
3
Left side air distribution
4
Defrosting
5
Increase air volume
6
Rear window defroster
7
Right side air distribution
8
Rear air conditioning
9
Temperature control, right
a
Automatic climate control on/off
b
Right side air distribution
c
Right side air distribution
d
AC cooling on/off (A/C)
Residual heat/ventilation (REST)
e
Display
f
Decrease air volume
g
Air recirculation
h
Left side air distribution
j
Left side air distribution
k
Interior temperature sensor
l
Adopt driver zone settings in other
zones
Page 221 of 539

220 Controls in detail3-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 218).Deactivating the climate control
system
Deactivating
Press button´ (
page 218).
Reactivating
Press buttonU(
page 218).
Warning!
G
Follow the recommended settings for heat-
ing and cooling given on the following pag-
es. Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iSevere conditions (e.g. strong air pollu-
tion) may require replacement of the fil-
ter before its scheduled interval. A
clogged filter will reduce the air volume
to the interior.
If the vehicle interior is hot, ventilate
the interior before driving off.
Keep the air intake grille in front of the
windshield free of snow and debris.
iWhen the air conditioning is switched
off, the outside air supply and circula-
tion are also switched off. Only choose
this settings for a short time. Otherwise
the windows could fog up.iYou can also press button´ on the
climate control panel.
If you press button0 to reactivate
the climate control system, the defrost-
ing mode is activated.
Page 222 of 539

221 Controls in detail
3-zone automatic climate control*
Rear air conditioning
You can switch on and off the rear air con-
ditioning with the climate control panel in
the front.
Deactivating
Press button> on the climate con-
trol panel (
page 218).
The indicator lamp on button>
comes on. The rear air conditioning is
switched off. REAR OFF
appears in the
climate control display.
Activating
Press button> on the climate con-
trol panel (
page 218).The indicator lamp on button>
goes out. The rear air conditioning is
adjusted automatically.
REAR ON
ap-
pears in the climate control display.
For more information on rear air condition-
ing, see “Rear air conditioning”
(
page 227).
Setting the temperature
Use temperature control1 and9
(page 218) to separately adjust the air
temperature on each side of the passenger
compartment. You should raise or lower
the temperature setting in small incre-
ments, preferably starting at 72°F (22°C).
The climate control will adjust to the set
temperature as fast as possible.Increasing
Turn the temperature control1
and/or9 slightly to the right.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
Decreasing
Turn the temperature control1
and/or9 slightly to the left.
The climate control system will corre-
spondingly adjust the interior air tem-
perature.
iFor information on operating the rear
climate control panel from the rear
seats, see “Rear air conditioning”
(page 227).
iYou can switch on and off the rear air
conditioning by pressing the respective
button on the rear climate control pan-
el.
Page 224 of 539

223 Controls in detail
3-zone automatic climate control*
Maximum cooling MAX COOL
If the air distribution control as well as the
airflow volume control are set toU and
there is a high need for cooling, the display
“MAX COOL” 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).Defrosting
If the air volume is switched off or the air
recirculation mode is switched on, the
interior is not any longer ventilated and the
windows can get fogged on the inside.Activating
Press button0 (
page 218).
The indicator lamp on button0
comes on.
The climate control switches automatically
to the following functions:
maximum blower and heating power
air flows onto the windshield and the
front side windows (side air vents must
be open)
The climatic compressor is switched on
at outside temperatures above approx-
imately 41°F (5°C) for air-drying
Deactivating
Press button0.
The yellow indicator lamp on the button
goes out. Defrosting is turned off.
Air recirculation mode
Switch to air recirculation mode to prevent
unpleasant odors from entering the vehicle
from the outside (e.g. before a tunnel trav-
el). This setting cuts off the intake of out-
side air and recirculates the air in the
passenger compartment.
iThese settings should only be selected
for a short time.
When the defrost setting has been se-
lected, only the rear window defroster
can be switched on. No other settings
are possible.
iTo switch off you can press also the
button´ orU.
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 225) is activated, or
press button0.