2008 MERCEDES-BENZ R350 cooling

226 Controls in detail
3-zone automatic climate control*
The air conditioning will not engage (no
cooling) if the A/C mode is deactivated
(
page 234).Deactivating the automatic climate
control system
Deactivating
Press button´ (page 224) until
the displaye (
page 224) is cleared.
The indicator lamp on the button
comes on.Reactivating
Press buttonU (page 224).
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 244). 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 setting for a short time.
Otherwise the windows could fog up,
impairing visibility and endangering you and
others.
iYou can also press button´
(
page 224) on the automatic climate control
panel.
If you press button| (
page 224) to reacti-
vate the automatic climate control system, the
defrosting mode is activated.

227 Controls in detail
3-zone automatic climate control*
Operating the automatic climate
control system in automatic mode
You can switch the automatic climate
control system on and off separately for
each zone as needed.
Activating
Press buttonU (page 224) while
the engine is running.
The indicator lamp on the button
comes on. Air volume and air distribu-
tion are controlled separately for each
zone.
Use temperature controls1 and9
(
page 224) to separately adjust the
air temperature on each side of the
passenger compartment.
The temperature of the interior is
adjusted automatically.
Deactivating
Press one button of the air distribution
(
page 224) or press button

orQ (
page 224).
The indicator lamp on the buttonU
goes out.
Depending on which button you press –
the air distribution button or the air vol-
ume button
or Q – automatic
control of either the air distribution or
air volume is switched off.
Setting the temperature
Use temperature controls1 and9
(
page 224) 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 automatic climate control will adjust
to the set temperature as fast as possible.
Increasing
Turn temperature control
1and/or9 slightly clockwise.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
Decreasing
Turn temperature control
1and/or9 slightly counterclock-
wise.
The automatic climate control system
will correspondingly adjust the interior
air temperature.
iWhen operating the automatic climate con-
trol system in automatic mode, you will only
rarely need to adjust the temperature, air volume
and air distribution.
In automatic mode, cooling with dehumidify is
switched on. This function can be switched off if
necessary.

231 Controls in detail
3-zone automatic climate control*
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 display.
This provides the fastest possible cooling
of the vehicle interior (when windows and
tilt/sliding sunroof* or tilt/sliding panel*
are closed).
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 224).
The indicator lamp on the button
comes on.
Warning!G
Fogged windows impair visibility, endanger-
ing 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 window
fogging persists, make sure the air
conditioning (
page 233) is activated, or
press button|.
iThe air recirculation mode is activated
automatically at high outside temperatures.
The indicator lamp on button:is not lit
when the air recirculation mode is switched on
automatically.
A quantity of outside air is added after
approximately 30 minutes.
If you have turned off the air conditioning
(
page 233) 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
switches to air recirculation. The indicator lamp
on button: is not lit when the system
switches to air recirculation automatically.

233 Controls in detail
3-zone automatic climate control*
Convenience opening:
Press button: for approximately
2 seconds.
The windows and/or tilt/sliding
sunroof will return to their previous
positions. You can release button:
once the opening procedure has
begun. The windows and tilt/sliding
sunroof continue opening until they
have reached their previous positions.
The indicator lamp on the button goes
out. The air recirculation mode is
deactivated.Vehicles with panorama roof*
Convenience closing:
Press and hold button: until the
windows and the tilt/sliding panel are
closed or have reached the desired po-
sition. The indicator lamp on the button
comes on. The air recirculation mode is
activated.
Convenience opening:
Press and hold button: until the
windows and the tilt/sliding panel are
opened or have reached the desired
position. The indicator lamp on the
button goes out. The air recirculation
mode is deactivated.
Air conditioning
The cooling function, only operational
when the engine is running, cools the
vehicle down to the selected interior
temperature. The cooling function also
dehumidifies the air in the vehicle interior,
thereby preventing the windows from
fogging up.
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.

234 Controls in detail
3-zone automatic climate control*
Deactivating
It is possible to deactivate the air condi-
tioning (cooling) function of the automatic
climate control system. The air in the
vehicle will then no longer be cooled or
dehumidified.
Press button9 (page 224).
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
temperature 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.
Activating
Adjust the temperature, air volume and
air distribution (
page 224).
Press button; (page 224).
The indicator lamp on the button
comes on.
The driver-side settings are used for all
temperature zones.
!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.

236 Controls in detail
3-zone automatic climate control*
Rear automatic climate control
(second row)
The control panel is located at the rear of
the front center console.
Rear automatic climate control panel
Activating rear automatic climate
control
Press buttonU.
The indicator lamp on the button
comes on. The temperature, air
volume, and air distribution are ad-
justed automatically.
Deactivating rear automatic climate
control
Press button´.
The indicator lamp on the button goes
out.
The cooling function switches off after
a short delay.
1Increasing air volume
2Air distribution and air volume
(automatic, manual)
3Air distribution (directs air through
the side air vents)
4Right rear center air vent, adjustable
5Air distribution (directs air through
the footwells and side air vents)
6Rear automatic climate control
on/off
7Decreasing air volume
8Left rear center air vent, adjustable
9Indicator lamps for air volume
settings
aTemperature control
iThe stored values for the rear automatic
climate control are erased from memory after
the ignition has been switched off for more than
30 minutes. Once the front automatic climate
control is switched on again, the rear automatic
climate control operates in automatic mode at a
preset temperature of 72°F (22°C).
iThe automatic climate control must be
switched on (
page 226).
iSwitch off the rear automatic climate
control for improved cooling or heating output in
the front passenger compartment.
You can also switch off the rear automatic
climate control from the front passenger
compartment (
page 237).

360 Operation
Engine compartment
Be careful not to spill any oil when adding.
Avoid environmental damage caused by oil
entering the ground or water.
Screw filler cap1 back on filler neck.
For more information on engine oil, see
“Technical data” section (
page 536) and
(
page 538).
Transmission fluid level
The transmission fluid level does not need
to be checked. If you notice transmission
fluid loss or gear shifting malfunctions,
have an authorized Mercedes-Benz Light
Truck Center check the automatic trans-
mission.Coolant level
The engine coolant is a mixture of water
and anticorrosion/antifreeze. To check
the coolant level, the vehicle must be
parked on level ground.
!Excess oil must be siphoned or drained off.
It could cause damage to the engine or
emission control system not covered by the
Mercedes-Benz Limited Warranty.
Warning!G
In order to avoid any potentially serious
burns:

Use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking from the cooling system,
or if the coolant temperature display
indicates that the coolant is overheated.

Do not remove pressure cap on coolant
reservoir if coolant temperature is
above 158°F (70°C). Allow engine to
cool down before removing cap. The
coolant reservoir contains hot fluid and
is under pressure.

Using a rag, slowly open the cap approx-
imately 1/2turn to relieve excess pres-
sure. If opened immediately, scalding


448 Practical hints
What to do if …
Display symbolDisplay messagePossible cause/consequencePossible solution
•Coolant Level
Stop car, switch engine off.The coolant is too hot.
Among other possible causes
(the cooling fan could be
malfunctioning), the poly-V-belt
could be broken.Stop the vehicle in a safe location or
as soon as it is safe to do so.
Turn off the engine.
Apply the parking brake (page 65).
Check the poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise
the engine will overheat due to an
inoperative water pump which may
result in damage to the engine.
Contact an authorized
Mercedes-Benz Light Truck Center.
If it is intact:
Wait for the message to disappear
before restarting the engine.
Doing otherwise could result in seri-
ous engine damage that is not
covered by the Mercedes-Benz
Limited Warranty.
(Continued on next page)