2008 MERCEDES-BENZ R320 keyless

474 Practical hints
Unlocking / locking in an emergency
Unlocking the vehicle
If you cannot unlock the vehicle with the
SmartKey or KEYLESS-GO*, open the
driver’s door using the mechanical key.Removing the mechanical key
1Mechanical key locking tab
2Mechanical key
Move locking tab1 in direction of
arrow.
Slide mechanical key2 out of the
housing.Unlocking the driver’s door
Insert mechanical key 2 into the
driver’s door lock until it stops.
Turn mechanical key 2 counterclock-
wise to position1 and hold it there.
Pull the door handle until the locking
knob moves up.
The driver’s door is unlocked.
Pull the door handle once more to open
the driver’s door.
iUnlocking the driver’s door with the
mechanical key will trigger the anti-theft
alarm system.
To cancel the alarm, insert the SmartKey or
SmartKey with KEYLESS-GO* in the starter
switch.
1Unlocking
2Mechanical key

475 Practical hints
Unlocking / locking in an emergency
Locking the vehicle
If you cannot lock the vehicle with the
SmartKey or KEYLESS-GO*, lock the
vehicle carrying out the following steps.
Close the front passenger door, the
rear right door and the tailgate.
Open the driver’s door and the rear left
door.
Press the central locking switch on the
driver’s door (
page 127).
The locking knobs of the front passen-
ger door and the rear doors move
down.
If the vehicle battery is disconnected or
drained:
Press down the locking knobs of
the front passenger door and the
rear doors manually.
Exit the vehicle.
Close the driver’s door.
Enter the vehicle through the rear left
door.
Press down the locking knob of the
driver’s door.
Exit the vehicle.
Close the rear left door.
The vehicle is locked.
Fuel filler flap
Open the tailgate (page 119).
The fuel filler flap release is located behind
a cover in the right side trim panel of the
cargo compartment.
1Lock
2Cover
!To prevent inadvertent lockout, make sure
to have the SmartKey or SmartKey with
KEYLESS-GO* with you before proceeding with
the next step. The next step will lock the vehicle.
iThis procedure does not arm the anti-theft
alarm system, nor does it lock the fuel filler flap.


479 Practical hints
Replacing SmartKey batteries
Replacing SmartKey batteries
If the batteries in the SmartKey or the
SmartKey with KEYLESS-GO* are
discharged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an autho-
rized Mercedes-Benz Light Truck Center.
Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key from the
SmartKey (
page 474).
1Mechanical key
2Battery compartment
Insert mechanical key 1 into opening.
Press mechanical key 1 in direction of
arrow.
The battery compartment is unlatched.
Pull battery compartment 2 out of the
SmartKey housing.
3Batteries
4Contact springs
Pull out batteries3.
Using a line-free cloth, insert new bat-
teries 3 under contact springs 4 with
the positive terminal (+) side facing up.
Return battery compartment 2 into
housing until it locks into place.
Slide mechanical key 1 back into
SmartKey.
Check the operation of the SmartKey
or SmartKey with KEYLESS-GO*.
Warning!G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen inserting batteries, make sure they
are clean and free of lint.
iWhen replacing batteries, always replace
both batteries. The required replacement
batteries are available at any Mercedes-Benz
Light Truck Center.

489 Practical hints
Replacing wiper blades
Replacing wiper blades
Front wiper blades
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Make sure the vehicle’s on-board
electronics have status0
(
page 41).Removing
Fold the wiper arms forward until they
engage.
1Wiper blade
2Tab
3Wiper arm
Press tabs2 together.
Tilt wiper blade 1 away from wiper
arm 3.
Take off wiper blade 1 in direction of
arrow.
Warning!G
For safety reasons, switch off wipers and
remove SmartKey from starter switch
(vehicles with KEYLESS-GO*: Make sure
the vehicle’s on-board electronics have
status0) before replacing a wiper blade.
Otherwise the motor could suddenly turn on
and cause injury.
Warning!G
Wiper blades are components that are
subject to wear and tear. Replace the wiper
blades twice a year, preferably in the spring
and fall. Otherwise the windows will not be
properly wiped. As a result, you may not
be able to observe surrounding traffic condi-
tions and could cause an accident.
!Never open the hood when the wiper arms
are folded forward.
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.
Do not allow the wiper arms to contact the wind-
shield glass without a wiper blade inserted.
For your convenience, we recommend that you
have this work carried out by an authorized
Mercedes-Benz Light Truck Center.!Do not pull on the wiper blade inserts. They
could tear.

490 Practical hints
Replacing wiper blades
Installing
1Wiper blade
2Attachment
3Guide tab
4Opening
With guide tab 3 sliding into
opening4, place wiper blade 1 onto
wiper arm in direction of arrow.
Fold wiper blade 1 towards wiper
arm.
Tabs 2 (
page 489) must engage
into both recesses of attachment 2.
Check whether the wiper blade is
securely fastened.
Fold the wiper arm backward to rest on
the windshield.
Make sure to hold on to the wiper when
folding the wiper arm back.
Rear wiper blade
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*
Make sure the vehicle’s on-board
electronics have status0
(
page 41).
!Make sure the wiper blades are properly in-
stalled. Improperly installed wiper blades may
cause windshield damage.
!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 rear
window.
Do not allow the wiper arm to contact the rear
window glass without a wiper blade inserted.
For your convenience, we recommend that you
have this work carried out by an authorized
Mercedes-Benz Light Truck Center.

492 Practical hints
Flat tire
Preparing the vehicle
Vehicles with AIRMATIC*:
Make sure the vehicle level is set to
highway level (
page 276).
Park the vehicle in a safe distance from
moving traffic on a hard, flat surface
when possible.
Turn on the hazard warning flasher
(
page 150).
Turn the steering wheel so that the
front wheels are in a straight-ahead
position.
Set the parking brake (page 65).
Set the automatic transmission to
position P (
page 190).
Turn off the engine (page 66).
Have any passenger exit the vehicle at
a safe distance from the roadway.
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Turn off the engine by pressing the
KEYLESS-GO* button once
(
page 66).
Open the driver’s door (this puts
the starter switch in position 0,
same as with the SmartKey re-
moved from the starter switch). The
driver’s door then can be closed
again.
Remove the KEYLESS-GO*
start/stop button from the starter
switch.
Warning!G
The dimensions of the spare wheel are
different from those of the road wheels. As
a result, the vehicle handling characteristics
change when driving with a spare wheel
mounted. Adapt your driving style accord-
ingly.
The spare wheel is for temporary use only.
When driving with spare wheel mounted,
ensure proper tire inflation pressure and do
not exceed a vehicle speed of
50 mph (80 km/ h).
Drive to the nearest Mercedes-Benz Light
Truck Center as soon as possible to have the
spare wheel replaced with a regular road
wheel.
Never operate the vehicle with more than
one spare wheel mounted.
Do not switch off the ESP
® with a spare
wheel mounted.
iOpen doors only when conditions are safe to
do so.

499 Practical hints
Flat tire
Inflating the collapsible tire
Take the electric air pump out of the
vehicle tool kit storage well
(
page 467).
Electric air pump
1Flap
2On/off switch
3Electrical plug
4Air hose with pressure gauge and vent
screw
5Union nut
Open flap 1 on electric air pump.
Pull out electrical plug 3 and air hose
with pressure gauge 4.
Remove the valve cap from the
collapsible tire valve.
Screw union nut 5 onto the
collapsible tire valve.
Insert electrical plug 3 into a power
outlet (
page 314).
Turn the SmartKey in the starter switch
to position1.
Vehicles with KEYLESS-GO*:
Press the KEYLESS-GO start/stop
button once without depressing the
brake pedal.
Press I on electric air pump switch 2.
The electric air pump should now
switch on and inflate the collapsible
tire.
Warning!G
Inflate collapsible tire only after the wheel is
properly mounted.
Inflate the collapsible tire using the electric
air pump (
page 467) before lowering the
vehicle.
Warning!G
Observe instructions on air pump label.
!Do not lower the vehicle before inflating the
collapsible tire. Otherwise the rim may be dam-
aged.
!The cigarette lighter (page 312) is not de-
signed for use with the electric air pump. Use a
power outlet (
page 314) for electric air pump
operation.


500 Practical hints
Flat tire
Inflate the spare wheel tire to the
recommended tire inflation pressure
given in the “Technical data” section
(
page 529).
This takes about 5 minutes for the
collapsible tire.
Press 0 on electric air pump switch 2.
Turn the SmartKey in the starter switch
to position0.
Vehicles with KEYLESS-GO*:
Press the KEYLESS-GO start/stop
button twice without depressing
the brake pedal.
If the tire inflation pressure is above
the recommended tire inflation pres-
sure given in this Operator’s Manual,
release excess tire inflation pressure
using the vent screw.
Detach the electric air pump.
Store the electrical plug and the air
hose behind the flap and place the
electric air pump back in the vehicle
tool kit storage well.
Warning!G
Air hose 4 and union nut5 can become
hot during inflation. Exercise proper caution
to avoid burning yourself when using the
equipment.
!Do not operate the electric air pump longer
than 8 minutes without interruption. Otherwise it
may overheat.
You may operate the electric air pump again
after it has cooled off.
!Please compare the recommended tire in-
flation pressure for your vehicle with the tire in-
flation pressure on the yellow label located on
the spare wheel rim.
If the tire inflation pressure on the yellow label
on the spare wheel rim differs from the values
given in this Operator’s Manual, inflate the tire to
the recommended tire inflation pressure given
on the yellow label on the spare wheel rim.Warning!G
Follow recommend tire inflation pressures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes,
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.