2008 MERCEDES-BENZ R320 key

340 Operation
Driving instructions
Power assistanceBrakes
Warning!G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle.
Warning!G
After driving in heavy rain for some time
without applying the brakes or through wa-
ter deep enough to wet brake components,
the first braking action may be somewhat
reduced and increased pedal pressure may
be necessary to obtain expected braking
effect. Maintain a safe distance from
vehicles in front.
Resting your foot on the brake pedal will
cause excessive and premature wear of the
brake pads.
It can also result in the brakes overheating,
thereby significantly reducing their effec-
tiveness. It may not be possible to stop the
vehicle in sufficient time to avoid an
accident.
!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 the vehicle is being towed
with one axle raised.
Active braking action through the ESP
® may
otherwise seriously damage the brake system
which is not covered by the Mercedes-Benz
Limited Warranty
!Vehicles with 4MATIC must not be towed
with one axle raised.
!Vehicles with 4MATIC:
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.

341 Operation
Driving instructions
To help prevent brake disk corrosion after
driving on wet road surfaces (particularly
salted roads), it is advisable to brake the
vehicle with considerable force prior to
parking. The heat generated serves to dry
the brakes.
If your brake system is normally only
subjected to moderate loads, you should
occasionally test the effectiveness of the
brakes by applying above-normal braking
pressure at higher speeds. This will also
enhance the grip of the brake pads.Refer to the description of the Brake Assist
System (BAS) (
page 101).
Brake pad wear or a leak in the system may
be the reason for low brake fluid level in
the reservoir.
The brake fluid level in the reservoir may
be too low if the brake warning lamp
in the instrument cluster comes on and an
acoustic warning sounds although the
parking brake is released (
page 415).
Observe additional messages in the multi-
function display that may appear
(
page 447).
Have the brake system inspected
immediately. Contact an authorized
Mercedes-Benz Light Truck Center.All checks and service work on the brake
system should be carried out by qualified
technicians only. Contact an authorized
Mercedes-Benz Light Truck Center.
Only install brake pads and brake fluid
recommended by Mercedes-Benz.
!Vehicles with 4MATIC:
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 test-
ing the parking brake on a brake test dynamom-
eter 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.
Warning!G
Make sure not to endanger any other road
users when carrying out these braking
maneuvers.
Warning!G
If other than recommended brake pads are
installed, or other than recommended brake
fluid is used, the braking properties of the
vehicle can be degraded to an extent that
safe braking is substantially impaired. This
could result in an accident.

343 Operation
Driving instructions
ParkingTires
Warning!G
Do not park this vehicle in areas where com-
bustible materials such as grass, hay or
leaves can come into contact with the hot
exhaust system, as these materials could be
ignited and cause a vehicle fire.
To reduce the risk of personal injury or dam-
age to the vehicle drivetrain as a result of
vehicle movement, before turning off the en-
gine and leaving the vehicle always:

Keep right foot on brake pedal.

Firmly depress parking brake pedal.

Shift the automatic transmission to
positionP.

Slowly release brake pedal.

When parked on an incline, turn front
wheel towards the road curb.

Turn the SmartKey in the starter switch
to position0 and remove the SmartKey
from the starter switch, or press the
start/stop button (vehicles with
KEYLESS-GO*).

Take the SmartKey or the SmartKey with
KEYLESS-GO* and lock vehicle when
leaving.
Warning!G
If you feel a sudden significant vibration or
ride disturbance, or you suspect that possi-
ble damage to your vehicle has occurred,
you should turn on the hazard warning
flashers, carefully slow down, and drive with
caution to an area which is a safe distance
from the road.
Inspect the tires and the vehicle underbody
for possible damage. If the vehicle or tires
appear unsafe, have the vehicle towed to
the nearest Mercedes-Benz Light Truck
Center or tire dealer for repairs.

352 Operation
At the gas station
Refueling
The fuel filler flap is located on the
right-hand side of the vehicle towards the
rear. Locking/unlocking the vehicle with
the SmartKey or the SmartKey with
KEYLESS-GO* automatically
locks/unlocks the fuel filler flap.
Turn off the engine

by turning the SmartKey to
position0 (
page 39). Remove the
SmartKey from the starter switch.

by pressing the KEYLESS-GO*
start/stop button (
page 41).
Open the driver’s door (with the
driver’s door open, starter switch is
now in position 0, same as
SmartKey removed from starter
switch).
Warning!G
Gasoline and diesel fuels are highly flamma-
ble and poisonous. They burn violently and
can cause serious personal injury.
Never allow sparks, flame or smoking mate-
rials near gasoline or diesel fuel!
Turn off the engine before refueling.
Whenever you are around gasoline or diesel
fuel, avoid inhaling fumes and skin or cloth-
ing contact, extinguish all smoking materi-
als.
Direct skin contact with gasoline or diesel
fuels and the inhalation of gasoline or diesel
fuel vapors are damaging to your health.
Warning!G
Do not fill diesel tanks with gasoline. Do not
mix diesel fuel with gasoline. Otherwise the
fuel system and engine could be damaged.
In addition, the vehicle could catch fire.
!Damage resulting from mixing gasoline with
diesel fuel is not covered by the Mercedes-Benz
Limited Warranty.
!Diesel engine: When filling the diesel fuel
tank using fuel containers, place a filling filter, a
suede cloth or a clean flannel cloth as a filter.
Otherwise, particles from the fuel container
could clog the fuel lines and/or the diesel
injection system.
iIn case the central locking system does not
release the fuel filler flap, see “Fuel filler flap”
(
page 475).

404 Operation
Vehicle care
Mercedes-Benz because of the possibility
of incompatibility between materials used
in the production process and others
applied later.
We have selected car-care products and
compiled recommendations which are
specially matched to our vehicles and
which always reflect the latest technology.
You can obtain Mercedes-Benz approved
car-care products at an authorized
Mercedes-Benz Light Truck Center.
Scratches, corrosive deposits, corrosion or
damage due to negligent or incorrect care
cannot always be removed or repaired with
the car-care products recommended here.
In such cases it is best to seek aid at an
authorized Mercedes-Benz Light Truck
Center.
The following topics deal with the cleaning
and care of your vehicle and give important
“how-to” information as well as references
to Mercedes-Benz approved car-care
products.Power washer
Tar stains
Quickly remove tar stains before they dry
and become more difficult to remove. A tar
remover is recommended.Paintwork, painted body components
Mercedes-Benz approved Paint Care
should be applied when water drops on the
paint surface do not “bead up”. This should
normally be done every 3 to 5 months, de-
pending on the climate and washing deter-
gent used.
Mercedes-Benz approved Paint Cleaner
should be applied if the paint surface
shows signs of dirt embedding (i.e. loss of
gloss).
Do not apply any of these products or wax
if your vehicle is parked in the sun or if the
hood is still hot.
Use the appropriate MB-Touch-Up
Stick for quick and provisional repairs
of minor paint damage (i.e. chips from
stones, vehicle doors, etc.).
!Follow the instructions provided by the
power washer manufacturer on maintaining a
distance between the vehicle and the nozzle of
the power washer.
Never use a round nozzle to power-wash tires.
The intense jet of water can result in damage to
the tire.
Always replace a damaged tire.
Always keep the jet of water moving across the
surface. Do not aim directly at electrical parts,
electrical connectors, seals, or other rubber
parts.
iVehicles with KEYLESS-GO*:
If a door handle is hit by a strong jet of water, and
a SmartKey with KEYLESS-GO* is in close
proximity, i.e. within approximately
3 ft (approximately 1 m), the vehicle could be
inadvertently locked or unlocked.
!Affixing stickers, adhesive tape or similar
materials to painted body components may dam-
age the paintwork.

405 Operation
Vehicle care
Engine cleaning
Prior to cleaning the engine compartment
make sure to protect electrical compo-
nents and connectors from the intrusion of
water and cleaning agents.
Corrosion protection, such as
MB Anticorrosion Wax, should be applied
to the engine compartment after every
engine cleaning. Before applying, all con-
trol linkage bushings and joints should be
lubricated. The poly-V-belt and all pulleys
should be protected from any wax.
Vehicle washing
In the winter, thoroughly remove all traces
of road salt as soon as possible.
When washing the vehicle underbody, do
not forget to clean the inner sides of the
wheels.Hand-wash
Do not use hot water or wash your vehicle
in direct sunlight.
Only use a mild car wash detergent,
such as Mercedes-Benz approved Car
Shampoo.
Thoroughly spray the vehicle with a dif-
fused jet of water.
Direct only a very weak spray towards
the ventilation intake.
Use plenty of water and rinse the
sponge and chamois frequently.
Rinse with clean water and thoroughly
dry with a chamois.
Do not allow cleaning agents to dry on
the finish.Automatic car wash
You can have your car washed in an auto-
matic car wash from the start. Automatic
car washes without brushes are prefera-
ble.
To protect the filter system, switch the
climate control system (
page 208) or
the automatic climate control system*
(
page 222) to air recirculation mode.
If the vehicle is very dirty, prewash it
before running it through the automatic
car wash.
iVehicles with KEYLESS-GO*:
If a door handle is hit by a strong jet of water, and
a SmartKey with KEYLESS-GO* is in close
proximity, i.e. within approximately
3 ft (approximately 1 m), the vehicle could be
inadvertently locked or unlocked.
!Do not use scouring agents on these parts.
Never apply strong force and only use a soft,
non-scratching cloth when cleaning the vehicle.
Do not attempt to wipe the surface with a dry
cloth or sponge.
Otherwise you may scratch or damage the paint.
!Do not clean your vehicle in an automatic
touchless car wash which uses caustic spray.
Otherwise the caustic spray will damage the
paint or ornamental moldings.
!Make sure that the windshield wiper switch
is set to0 (
page 60). Otherwise, the rain
sensor could activate and cause the wipers to
move unintentionally. This may lead to vehicle
damage.
Due to the width of the vehicle, fold in exterior
rear view mirrors prior to running the vehicle
through an automatic car wash to prevent
damage to the mirrors.

406 Operation
Vehicle care
When taking the vehicle through an auto-
matic conveyor type car wash, observe the
following instructions.Vehicles with SmartKey:
With the vehicle at a standstill and the
ignition switched on shift the
automatic transmission to neutral
positionN.
If engaged, release the parking brake
(
page 56).
Switch off the ignition and leave the
SmartKey in the starter switch.
Vehicles with KEYLESS-GO*:
With the vehicle at a standstill, depress
the brake pedal and keep it pressed.
With the ignition switched on shift the
automatic transmission to park
positionP.
Release the brake pedal.
Remove the KEYLESS-GO* start/stop
button from the starter switch
(
page 41).
Insert the SmartKey with
KEYLESS-GO* into the starter switch.
Switch on the ignition.
Depress the brake pedal.
Shift the automatic transmission to
neutral positionN.
Release the brake pedal.
If engaged, release the parking brake
(
page 56).
Switch off the ignition and leave the
SmartKey with KEYLESS-GO* in the
starter switch.
Warning!G
When leaving the SmartKey or SmartKey
with KEYLESS-GO* in the starter switch, do
not leave children unattended in the vehicle.
It is possible for children to switch on the
ignition which could result in unsupervised
use of vehicle equipment.
A child’s unsupervised access to a vehicle
could result in an accident and/or serious
personal injury.
iAfter running the vehicle through an auto-
matic car wash, wipe any wax off of the wind-
shield (
page 409). This will prevent smears
and reduce wiping noise which can be caused by
residual wax on the windshield.
When leaving the car wash, make sure that the
mirrors are folded out. Otherwise they may
vibrate.

409 Operation
Vehicle care
Cleaning the windows and the wiper
blades
Fold wiper arms forward until they snap
into place.
Clean the wiper blade inserts with a
clean cloth and detergent solution.
Use a soft, clean cloth and a mild
window cleaning solution on all outside
and inside glass surfaces.
An automotive glass cleaner is recom-
mended.!Do not clean the camera and the area
around the camera:

with a high-pressure cleaner

with a dry cloth and high pressure

with aggressive cleaning agents
You could otherwise damage the camera.
Warning!G
For safety reasons, switch off wipers and re-
move SmartKey from starter switch
(vehicles with KEYLESS-GO*: Make sure the
vehicle’s on-board electronics have
status0) before cleaning the windshield
and/or the wiper blades. Otherwise, the
wiper motor could suddenly turn on and
cause injury.
!Do not pull on the wiper blade inserts. They
could tear.
!Fold the windshield wiper arms back onto
the windshield before turning the SmartKey in
the starter switch or pressing the KEYLESS-GO
start/stop button (vehicles with KEYLESS-GO*).
Hold on to the wiper when folding the wiper arm
back. If released, the force of the impact from
the tensioning spring could crack the windshield.
!To clean the window interior, do not use a
dry cloth, abrasives, solvents or cleaners con-
taining solvents. Do not touch the inside of the
front, rear or side windows with hard objects
such as an ice scraper or ring. Doing so may
damage the windows.