warning light MERCEDES-BENZ R320 2008 W251 Service Manual

169 Controls in detail
Control system
Vehicle status message memory menu
Use the vehicle status message memory
menu to scan malfunction and warning
messages that may be stored in the
system. Such messages appear in the
multifunction display and are based on
conditions or system status the vehicle’s
system has recorded.
The vehicle status message memory menu
only appears, if messages have been
stored.
Press buttonè orÿ repeatedly
until the vehicle status message
memory appears in the multifunction
display.If conditions have occurred causing status
messages to be recorded, the number of
messages appears in the multifunction
display:
Press buttonk orj.
The stored messages will now be
displayed in the order in which they
have occurred. For malfunctions and
warning messages, see “Vehicle status
messages in the multifunction display”
(
page 427).
Warning!G
Malfunction and warning messages are only
indicated for certain systems and are inten-
tionally not very detailed. The malfunction
and warning messages are simply a remind-
er with respect to the operation of certain
systems and do not replace the owner’s
and/or driver’s responsibility to maintain
the vehicle’s operating safety by having all
required maintenance and safety checks
performed on the vehicle and by bringing
the vehicle to an authorized Mercedes-Benz
Light Truck Center to address the malfunc-
tion and warning messages (
page 427).
iAfter you have scrolled through all recorded
status messages, the first recorded message
appears again.

197 Controls in detail
Automatic transmission
Driving tips
Accelerator position
Your driving style influences the
transmission’s shifting behavior:
Less throttle Earlier upshifting
More throttle Later upshifting
Kickdown
Use kickdown when you want maximum
acceleration.
Press the accelerator past the point of
resistance.
Depending on the engine speed the
transmission shifts into a lower gear.
Ease on the accelerator when you have
reached the desired speed.
The transmission shifts up again.Stopping
When you stop briefly, e.g. at traffic lights:
Leave the transmission in gear.
Hold the vehicle with the brake.
When you stop for a longer period of time
with the engine idling and/or on a hill:
Set the parking brake.
Shift into park positionP.
Maneuvering
When you maneuver in tight areas,
e.g. when pulling into a parking space:
Control the vehicle speed by gradually
releasing the brakes.
Accelerate gently.
Never abruptly step on the accelerator.
Warning!G
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock the vehicle. Do not leave children unat-
tended in the vehicle, or with access to an
unlocked vehicle. Children could shift the
automatic transmission out of park
positionP, which could result in an accident
and/or serious personal injury.

204 Controls in detail
Good visibility
Power folding exterior rear view
mirrors*
Folding the exterior rear view mirrors
in and out automatically
When the corresponding function in the
control system is activated (
page 184):

The exterior rear view mirrors automat-
ically fold in as soon as the vehicle is
locked from the outside.

The exterior rear view mirrors automat-
ically fold out as soon as the vehicle is
unlocked and the driver’s or front pas-
senger door are subsequently opened.Synchronizing exterior rear view
mirrors
The power folding rear view mirrors may
have to be synchronized after the vehicle
battery has been disconnected or
discharged. If the exterior rear view
mirrors do not fold properly upon locking
or unlocking the vehicle although the
corresponding function in the control
system is activated (
page 184), do the
following:
Fold each exterior rear view mirror in
completely (
page 205).
Fold each exterior rear view mirror out
completely (
page 205).
When the exterior rear view mirrors fold
properly upon locking the vehicle, the
exterior mirrors are synchronized.
Otherwise repeat the above steps.
Warning!G
The auto-dimming function does not react if
incoming light is not aimed directly at sen-
sors in the interior rear view mirror.
The interior rear view mirror and the exterior
rear view mirror on the driver’s side do not
react, for example, when transporting cargo
which covers the rear window.
Light hitting the mirror(s) at certain angles
(incident light) could blind you. As a result,
you may not be able to observe the traffic
conditions and could cause an accident.
Warning!G
Exercise care when using the passen-
ger-side exterior rear view mirror. The mirror
surface is convex (outwardly curved surface
for a wider field of view). Objects in mirror
are closer than they appear. Check your
interior rear view mirror or glance over your
shoulder before changing lanes.
!Before you drive the vehicle through an
automatic car wash, fold in the exterior rear view
mirrors. Otherwise they may get damaged.

211 Controls in detail
Climate control
The climate control is operational when-
ever the engine is running. You can oper-
ate the climate control system in either the
automatic or manual mode. The system
cools or heats the interior depending on
the selected interior temperature and the
current outside temperature.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 219).
Warning!G
When operating the climate control, the air
that enters the passenger compartment
through the air vents can be very hot or very
cold (depending on the set temperature).
This may cause burns or frostbite to unpro-
tected skin in the immediate area of the air
vents.
Always keep sufficient distance between un-
protected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 210) to direct the air to air
vents in the vehicle interior that are not in
the immediate area of unprotected skin.
Warning!G
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled replacement 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 pag-
es. 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 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.

219 Controls in detail
Climate control
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 button9 (page 210).
The indicator lamp on the button goes
out.
Activating
Moist air can fog up the windows. You can
dehumidify the air with the air condition-
ing.
Press button9 (page 210) again.
The indicator lamp on the button
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
Switch off the ignition (page 39).
Press button9 (page 210).
The indicator lamp on the button
comes on.
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 inte-
rior 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.
iHow long the system will provide heating
depends on

the coolant temperature

the battery voltage
Regardless of the temperature and air volume
set on the climate control panel, an interior tem-
perature is aimed at by 72°F (22°C) and the
blower runs on low speed to protect the vehicle
battery.

225 Controls in detail
3-zone automatic climate control*
The automatic climate control is a 3-zone
intelligent automatic climate control
system. Your vehicle interior is divided
into 3 zones.With the help of a sun sensor, the
automatic climate control determines the
relation of the sun to the vehicle and auto-
matically adjusts the inside temperature
for each individual zone.The automatic climate control is oper-
ational whenever the engine is running. It
cools the vehicle’s interior according to the
angle and intensity of the sun’s rays, the
outside temperature and the selected tem-
perature. You can operate the automatic
climate control in either the automatic or
manual mode.
Nearly all dust particles, pollutants and
odors are filtered out before outside air
enters the passenger compartment
through the air distribution system.
Warning!G
When operating the automatic climate
control, the air that enters the passenger
compartment through the air vents can be
very hot or very cold (depending on the set
temperature). This may cause burns or frost-
bite to unprotected skin in the immediate
area of the air vents.
Always keep sufficient distance between
unprotected parts of the body and the air
vents. If necessary, use the air distribution
controls (
page 224) to direct the air to air
vents in the vehicle interior that are not in
the immediate area of unprotected skin.Warning!G
Severe conditions (e.g. strong air pollution)
may require replacement of the filter before
its scheduled replacement 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.

241 Controls in detail
Power windows
Power windows
The door windows and the hinged quarter
windows* are opened and closed electri-
cally. The switches for all door windows
and the hinged quarter windows* are
located on the driver’s door control panel.
The switches for the respective door win-
dows are located on the front passenger
door and the rear doors. The hinged
quarter windows* can be operated from
the driver’s seat only.
Switch on the ignition (page 39).
Warning!G
When closing the windows, make sure that
there is no danger of anyone being harmed
by the closing procedure.
Activate the override switch (
page 97)
when children are riding in the back seats of
the vehicle. The children could otherwise in-
jure themselves, e.g. by becoming trapped
in the window opening.
The closing of a door window can be imme-
diately halted by releasing the switch or, if
switch was pulled past the resistance point
and released, by either pressing or pulling
the respective switch.
If a door window encounters an obstruction
that blocks its path in a circumstance where
you pulled the switch past the resistance
point and released it to close the door win-
dow, the automatic reversal function will
stop the door window and open it slightly.
If a door window encounters an obstruction
that blocks its path in a circumstance where
you are closing a door window by pulling and
holding the switch, or by pressing and hold-
ing button‹on the SmartKey, by press-
ing and holding the lock button (vehicles
with KEYLESS-GO*) on the door handle, the
automatic reversal function will not operate.
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from starter switch, take it with you, and
lock the vehicle. Do not leave childrenunattended in the vehicle, or with access to
an unlocked vehicle. A child’s unsupervised
access to a vehicle could result in an
accident and/or serious personal injury.
iYou can also open or close the windows
using the SmartKey, see “Summer opening
feature” (
page 244) and “Convenience
closing feature” (
page 245).
Depending on the current position, the power
windows may also open or close when the air
recirculation button:on the control panel
of the climate control (
page 210) or automatic
climate control* (
page 224) is pressed and
held.
iAfter switching off the ignition (page 39)
or removing the SmartKey from the starter
switch, the windows can be operated

until you open the driver’s or front passenger
door

for at least 5 minutes if nor door was opened

248 Controls in detail
Power tilt/sliding sunroof*
Opening and closing
Warning!G
When closing the tilt/sliding sunroof, make
sure that there is no danger of anyone being
harmed by the closing procedure.
If the tilt/sliding sunroof encounters an
obstruction that blocks its path in a circum-
stance where you are closing the tilt/sliding
sunroof by moving the tilt/sliding sunroof
switch past the resistance point, or by
pressing and holding button‹on the
SmartKey, by pressing and holding the lock
button (vehicles with KEYLESS-GO*) on the
door handle, the automatic reversal function
will not operate.
The opening/closing procedure of the
tilt/sliding sunroof can be immediately
halted by releasing the switch or, if the
switch was moved past the resistance point
and released, by moving the switch in any
direction.
The tilt/sliding sunroof is made out of glass.
In the event of an accident, the glass may
shatter. This may result in an opening in the
roof.
In a vehicle rollover, occupants not wearing
their seat belts or not wearing them properly
may be thrown out of the opening. Such an
opening also presents a potential for injury
for occupants wearing their seat belts prop-
erly as entire body parts or portions of them
may protrude from the passenger compart-
ment.
When leaving the vehicle, always remove the
SmartKey or SmartKey with KEYLESS-GO*
from the starter switch, take it with you, and
lock your vehicle. Do not leave children
unattended in the vehicle, or with access to
an unlocked vehicle. A child’s unsupervised
access to a vehicle could result in an
accident and/or serious personal injury.!To avoid damaging the seals, do not trans-
port any objects with sharp edges which can
stick out of the tilt/sliding sunroof.
Do not open the tilt/sliding sunroof if there is
snow or ice on the roof, as this could result in
malfunctions.
!Please keep in mind that weather conditions
can sometimes change rapidly. Make sure to
close the tilt/sliding sunroof when leaving the
vehicle. If water enters the vehicle interior,
vehicle electronics could be damaged which is
not covered by the Mercedes-Benz Limited
Warranty.
iWhen the tilt/sliding sunroof is open,
resonance noises may result in addition to the
usual wind noises. They are caused by minimal
pressure changes in the passenger compart-
ment. To reduce or eliminate theses noises,
change the position of the tilt/sliding sunroof or
open a door window slightly.

250 Controls in detail
Power tilt/sliding sunroof*
Fully opening (Express-open) and
closing (Express-close)
To fully open or close the tilt/sliding
sunroof, move the sunroof switch past
the resistance point in the required
direction1or2 (
page 249) and
release.
The tilt/sliding sunroof opens or closes
completely.
Stopping the power tilt/sliding sunroof
during Express-open
Move the sunroof switch in any
direction.
The movement of the tilt/sliding
sunroof stops.
Synchronizing
The tilt/sliding sunroof must be
synchronized

after the battery has been
disconnected or discharged

after a malfunction

if the tilt/sliding sunroof does not open
smoothly
iIf the movement of the tilt/sliding sunroof is
blocked during the closing procedure, the
tilt/sliding sunroof will stop and reopen slightly.
Warning!G
If the tilt/sliding sunroof encounters an
obstruction that blocks its path in a circum-
stance where you are closing the tilt/sliding
sunroof by moving the tilt/sliding sunroof
switch past the resistance point, or by
pressing and holding button‹on the
SmartKey, by pressing and holding the lock
button (vehicles with KEYLESS-GO*) on the
door handle, the automatic reversal function
will not operate.
The opening/closing procedure of the
tilt/sliding sunroof can be immediately
halted by releasing the switch or, if the
switch was moved past the resistance point
and released, by moving the switch in any
direction.
!If the tilt/sliding sunroof cannot be closed
or synchronized, contact an authorized
Mercedes-Benz Light Truck Center or call
Roadside Assistance (
page 325).

253 Controls in detail
Panorama roof with power tilt/sliding panel*
Opening and closing the panorama roof
with power tilt/sliding panel
Switch on the ignition (page 39).
Warning!G
When opening or closing the tilt/sliding
panel, make sure that there is no danger of
anyone being harmed by the opening or
closing procedure.
The opening procedure of the tilt/sliding
panel can be immediately halted by releas-
ing the switch or, if the switch was moved
past the resistance point and released, by
moving the switch in any direction.
The closing procedure of the tilt/sliding
panel can be immediately halted by releas-
ing the switch.
The panorama roof with power tilt/sliding
panel is made out of glass. In the event of
an accident, the glass may shatter. This may
result in an opening in the roof.
In a vehicle rollover, occupants not wearing
their seat belts or not wearing them properly
may be thrown out of the opening. Such an
opening also presents a potential for injury
for occupants wearing their seat belts
properly as entire body parts or portions of
them may protrude from the passenger
compartment.
When leaving the vehicle, always remove the
SmartKey or the SmartKey with
KEYLESS-GO* from the starter switch, take
it with you, and lock the vehicle. Do not
leave children unattended in the vehicle, or
with access to an unlocked vehicle.
A child’s unsupervised access to a vehicle
could result in an accident and/or serious
personal injury.
!To avoid damaging the seals, do not trans-
port any objects with sharp edges which can
stick out of the tilt/sliding panel.
Do not open the tilt/sliding panel if there is
snow or ice on the roof, as this could result in
malfunctions.
!Please keep in mind that weather conditions
can sometimes change rapidly. Make sure to
close the tilt/sliding panel when leaving the
vehicle. If water enters the vehicle interior,
vehicle electronics could be damaged which is
not covered by the Mercedes-Benz Limited
Warranty.
iWhen the tilt/sliding panel is open,
resonance noises may result in addition to the
usual wind noises. They are caused by minimal
pressure changes in the passenger compart-
ment. To reduce or eliminate theses noises,
change the position of the tilt/sliding panel or
open a door window slightly.
iYou can also open or close the tilt/sliding
panel using the SmartKey or the KEYLESS-GO*
function, see “Summer opening feature”
(
page 244) and “Convenience closing
feature” (
page 245).
iThe tilt/sliding panel may also open when
using the air recirculation button: on the
control panel of the climate control
(
page 210) or automatic climate control*
(
page 224).