2008 MERCEDES-BENZ R320 sensor

210 Controls in detail
Climate control
1Temperature control, left
2Air distribution and air volume
(automatic, manual)
3Front defroster
4Increasing air volume
5Air distribution (directs air through
the windshield and side air vents)
6Rear climate control* on/off
Air supply for rear passenger
compartment on/off
:USA only
7Temperature control, right
8AC cooling on/off
Residual heat/ventilation
9Air distribution (directs air through
center and side air vents)
aAir distribution (directs air through
the footwells and side air vents)
bAir volume display
cDecreasing air volume
dRear window defroster
eAir recirculation
fInterior temperature sensor
gClimate control on/off

224 Controls in detail
3-zone automatic climate control*
1Temperature control, driver’s side
2Air distribution and air volume
(automatic, manual)
3Air distribution, driver’s side
4Front defroster
5Increasing air volume
6Rear window defroster
7Air distribution, passenger side
8Rear automatic climate control
on/off
>USA only
™Canada only
9Temperature control, passenger side
aAutomatic climate control on/off
bAir distribution, passenger side
cAir distribution, passenger side
dAC cooling on/off
Residual heat/ventilation
eDisplay
fDecreasing air volume
gAir recirculation
hAir distribution, driver’s side
jAir distribution, driver’s side
kInterior temperature sensor
lAdopting driver’s side settings for all
zones

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.

243 Controls in detail
Power windows
Remove the obstruction.
Pull the respective door window switch
past the resistance point again and
release.
Stopping door windows during
Express-operation
Press or pull the respective door
window switch again.
Hinged quarter windows*
The switches for opening and closing the
hinged quarter windows are located on the
door control panel of the driver’s door.
1Hinged quarter windows: opening
2Hinged quarter windows: closingOpening
Press and release switch 1.
To stop the hinged quarter window:
Press and release switch 1 once
more.
Closing
Press and release switch 2.
To stop the hinged quarter window:
Press and release switch 2 once
more.
iIf the upward movement of a door window is
blocked during the closing procedure, the door
window will stop and open slightly.
iIf the door window still does not close when
there is no obstruction, pull and hold the respec-
tive power window switch. The door window will
then close without the obstruction sensor
function.
iWhen the obstruction sensor detects the
hinged quarter window is blocked during the
closing process, it will stop and open slightly.

262 Controls in detail
Driving systems
Adjustment in 5 mph
(Canada: 10 km/h) increments
Briefly press the cruise control lever
down past the resistance point in
direction of arrow2.
Release the cruise control lever.
The vehicle set speed decreases in
increments of 5 mph
(Canada: 10 km/h).Setting to last stored speed
(“Resume” function)
Briefly pull the cruise control lever in
direction of arrow4 (
page 258).
The cruise control resumes to the last
set speed or, if no speed is stored, it
will set and store the current speed.
Remove your foot from the accelerator
pedal.
The last set speed appears in the multi-
function display for approximately
5 seconds.
Distronic* (Canada only)
The Distronic is available on the
R5504MATIC only.
When activated, the Distronic adaptive
cruise control system increases the driving
convenience afforded by the cruise control
while traveling on expressways and other
major roadways.

If the Distronic distance sensor detects
a slower moving vehicle directly ahead,
your vehicle speed will be reduced so
that you follow that vehicle at your
preset following distance.

If there is no vehicle directly ahead of
you, Distronic will function in the same
way as standard cruise control
(
page 257).
iThe set speed value is decreased in 5 mph
(Canada: 10 km/h) increments each time you
press the cruise control lever down past the
resistance point.
iThe new speed is set and the vehicle will
decelerate. Keep in mind that it may take a brief
moment until the vehicle has reached the set
speed.
Warning!G
The set speed stored in memory should only
be set again if prevailing road conditions
permit. Possible acceleration or decelera-
tion differences arising from returning to the
preset speed could cause an accident
and/or serious injury to you and others.

264 Controls in detail
Driving systems
Distronic does not act upon adverse sight
and distance conditions. Do not use
Distronic during conditions of fog, heavy
rain, snow or sleet.
Warning!G
Distronic cannot take weather conditions
into account. Switch off Distronic or do not
switch it on if:

roads are slippery or covered with snow
or ice. The wheels could lose traction
while braking or accelerating, and the
vehicle could skid.

the sensor is dirty or visibility is
diminished due to snow, rain or fog, for
example. The distance control system
functionality could be impaired.
Always pay attention to surrounding traffic
conditions even while Distronic is switched
on. Otherwise, you may not be able to recog-
nize dangerous situations until it is too late.
This could cause an accident in which you
and others could be injured.
Warning!G
The “Resume” function should only be
operated if the driver is fully aware of the
previously set speed and wishes to resume
this particular preset speed.
Warning!G
Close attention to road and traffic condi-
tions is imperative at all times, regardless of
whether or not Distronic is activated.
Use of Distronic can be dangerous on
winding roads or in heavy traffic because
conditions do not allow safe driving at a
continuous speed.
Distronic will not react to stationary objects
in the roadway (e.g. a stopped vehicle in a
traffic jam or a disabled vehicle). Distronic
will also not respond to oncoming vehicles.
Switch off Distronic:

when changing from the left to the right
lane if vehicles are moving more slowly
in the left lane

when entering a turn lane or highway off
ramp

in complex driving situations, such as in
highway construction zones
In these situations, Distronic will continue to
maintain the set speed unless deactivated.
Distronic is designed and intended only to
maintain a set speed and keep a set dis-
tance from moving objects in front of it.


274 Controls in detail
Driving systems
The most likely cause for a malfunctioning
system is a dirty sensor (located behind
the hood grille), especially at times of snow
and ice or heavy rain. In such a case,
Distronic will switch off, and the message
DISTRONIC Currently Unavailable See
Operator’s Manual
appears in the multi-
function display.
For cleaning and care of the Distronic sen-
sor, see “Cleaning the Distronic* system
sensor cover” (
page 407).Turns and bends
In turns or bends, Distronic may not detect
a moving vehicle in front, or it may detect
one too soon. This may cause your vehicle
to brake late or unexpectedly.Offset driving
A vehicle traveling in your lane but offset
from your direct line of travel may not be
detected by Distronic. There will be insuffi-
cient distance to the vehicle ahead.
iIf the message DISTRONIC Available
Again
appears during driving, the dirt (e.g.
slush) has dissolved; Distronic works again, if
you reactivate it (
page 268).

281 Controls in detail
Driving systems
Permanent four-wheel drive (4MATIC)*
Your vehicle is equipped with permanent
four-wheel drive (4MATIC). Both, the front
and rear axles, are powered at all times
when the vehicle is being operated. The
4MATIC improves traction in conjunction
with the ESP
® (page 101) and the
Electronic Traction System (
page 103).
Parktronic* (Parking assist)
Warning!G
If a drive wheel is spinning due to insuffi-
cient traction:

While driving off, apply as little throttle
as possible.

While driving, ease up on the accelera-
tor.

Adapt your speed and driving style to
the prevailing road conditions.
Failure to observe these guidelines could
cause the vehicle to skid.
The 4MATIC cannot prevent accidents re-
sulting from excessive speed.
!Operational or performance test must only
be conducted on a two-axle dynamometer. If
such tests are necessary, contact an authorized
Mercedes-Benz Light Truck Center. You could
otherwise seriously damage the brake system or
the transfer case which is not covered by the
Mercedes-Benz Limited Warranty.
!Because the ESP® operates automatically,
the engine and ignition must be shut off
(SmartKey in starter switch position0 or1 or
KEYLESS-GO* start/stop button in
position0or1) when testing the parking brake
on a brake test dynamometer and such testing
should be no longer than 10 seconds.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty.
iIn winter operation, the maximum effective-
ness of the 4MATIC is only achieved with winter
tires (
page 398) or snow chains as required.
Warning!G
Parktronic is a supplemental system. It is
not intended to, nor does it replace, the
need for extreme care. The responsibility
during parking and other critical maneuvers
always remains with the driver.
Special attention must be paid to objects
with smooth surfaces or low silhouettes
(e.g. trailer couplings, painted posts, or road
curbs). Such objects may not be detected by
the system and can damage the vehicle.
The operational function of the Parktronic
system can be affected by dirty sensors,
especially at times of snow and ice, see
“Cleaning the Parktronic* system sensors”
(
page 408).
Interference caused by other ultrasonic
signals (e.g. working jackhammers, car
wash, or the air brakes of trucks) can cause
the system to send erratic indications, and
should be taken into consideration.