2008 MERCEDES-BENZ R320 warning light

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.

494 Practical hints
Flat tire
Prevent the vehicle from rolling away
by blocking wheels with wheel chocks
or other sizeable objects.
One wheel chock is included with the
vehicle tool kit (
page 469).Changing wheel on a level surface
Changing rear wheel on passenger side
(Example illustration)
Place the wheel chock in front of and
another sizeable object behind the
wheel that is diagonally opposite to the
wheel being changed.
Always firmly set parking brake and block
wheels with wheel chocks or other sizeable
objects before raising vehicle with jack. Do
not disengage parking brake while the vehi-
cle is raised.
Make sure that the ground on which the
vehicle is standing and where you place the
jack is solid, level and not slippery. If neces-
sary, use a large underlay. On slippery
surfaces, such as tiled floors, you should
use a non-slip underlay, for example a
rubber mat.
Do not use wooden blocks or similar objects
to support the jack. Otherwise the jack may
not be able to achieve its load-bearing
capacity if it is not at its full height.
Never start the engine when the vehicle is
raised.
Also observe the notes on the jack.
Warning!G
Only jack up the vehicle on level ground or
on slight inclines/declines. Otherwise, the
vehicle could fall off the jack and injure you
or others.


498 Practical hints
Flat tire
Mounting the spare wheel
1Wheel bolt for 18", 19", and 20" light al-
loy wheels
2Wheel bolt for spare wheel (located in
cargo compartment with spare wheel)
Clean contact surfaces of wheel and
wheel hub.
Guide spare wheel onto the alignment
bolt and push it on.
Insert wheel bolts and tighten them
slightly.
Unscrew the alignment bolt, install last
wheel bolt and tighten slightly.
!Wheel bolts2 must be used when mount-
ing the spare wheel with collapsible tire.
The use of any wheel bolts other than wheel
bolts2 for the spare wheel with collapsible tire
will physically damage the vehicle’s brakes.
!To avoid paint damage, place wheel flat
against hub and hold it there while installing first
wheel bolt.
Warning!G
Always replace wheel bolts that are
damaged or rusted.
Never apply oil or grease to wheel bolts.
Damaged wheel hub threads should be
repaired immediately. Do not continue to
drive under these circumstances! Contact
an authorized Mercedes-Benz Light Truck
Center or call Roadside Assistance.
Incorrect wheel bolts or improperly tight-
ened wheel bolts can cause the wheel to
come off. This could cause an accident.
Make sure to use the correct wheel bolts.
Warning!G
Only use genuine Mercedes-Benz wheel
bolts. Other wheel bolts may come loose.
Do not tighten the wheel bolts when the
vehicle is raised. Otherwise the vehicle
could fall off the jack.

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.


503 Practical hints
Battery
Battery
The battery is located under the front
passenger seat.
The battery should always be sufficiently
charged in order to achieve its rated
service life.
If you use your vehicle mostly for
short-distance trips, you will need to have
the battery charge checked more
frequently.
When replacing the battery, always use
batteries approved by Mercedes-Benz.
If you do not intend to operate your vehicle
for an extended period of time, consult an
authorized Mercedes-Benz Light Truck
Center about steps you need to observe.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.
iMercedes-Benz recommends to have the
battery replaced at authorized Mercedes-Benz
Light Truck Center.
Warning!G
Observe all safety instructions and precau-
tions when handling automotive batteries.
Risk of explosion.
Fire, open flames and smoking
are prohibited when handling
batteries. Avoid creating sparks.
Battery acid is caustic. Do not
allow it to come into contact
with skin, eyes or clothing.
Wear suitable protective cloth-
ing, especially gloves, apron and
faceguard.
Wear eye protection.
Rinse any acid spills imme-
diately with clear water. Contact
a physician if necessary.
Keep children away.
Follow the instructions in this
Operator’s Manual.

504 Practical hints
Battery
!The battery is a valve-regulated lead acid
(VRLA) battery, also referred to as “fleece”
battery. Such batteries do not require topping-up
of the electrolyte level. VRLA batteries therefore
do not have cell caps and the battery cover is
non-removable. Do not attempt to open the
battery as otherwise the battery will be dam-
aged.
Even though VRLA batteries do not require
topping-up of the electrolyte level and cannot be
opened to check the electrolyte level, the
battery condition must be checked periodically
by performing a battery conductance test. Refer
to Maintenance Booklet for battery condition
testing intervals.
As with any other battery, the battery may
discharge if the vehicle is not operated for an
extended period of time. You can connect a
battery maintenance charge unit tested and
approved for use on your vehicle model or dis-
connected the battery to prevent battery dis-
charge. Contact an authorized Mercedes-Benz
Light Truck Center for more information.!The factory-equipped VRLA battery is
leak-proofed. Only use a battery as replacement
that has the same security features and is of
identical size, voltage, and capacity as the
factory-equipped battery.
The battery, the battery ventilation and the later-
al plug must always be securely installed when
the vehicle is in operation.
Warning!G
Jump starting must only be done using the
jump-start contacts located in the engine
compartment (
page 511).
Warning!G
Failure to follow these instructions can re-
sult in severe injury or death.
Observe all safety instructions and precau-
tions when handling automotive batteries
(
page 503).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking etc.

505 Practical hints
Battery
Disconnecting, removing, reinstalling
and reconnecting the battery
Step 1 (Disconnecting)
Set the automatic transmission to
positionP (
page 192).
Firmly depress the parking brake
(
page 65).
Turn off the engine (page 66).
Leave the ignition switched on
(
page 39).
!Never loosen or detach battery terminal
clamps while the engine is running or the
SmartKey is in the starter switch. Otherwise the
alternator and other electronic components
could be severely damaged.
Have the battery checked regularly by an autho-
rized Mercedes-Benz Light Truck Center.
Contact your authorized Mercedes-Benz Light
Truck Center for further information.
Warning!G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.
Warning!G
Disconnecting, removing, reinstalling and
reconnecting the battery is a complicated
and technically demanding procedure that
also requires safety precautions to avoid the
risk of injury. We strongly recommend that it
be performed by a qualified technician or an
authorized Mercedes-Benz Light Truck
Center only. Please read the instructions
fully before beginning operation and only
undertake it if you feel fully capable of
performing all of the tasks involved as
described in these instructions. Observe all
safety instructions and precautions when
handling automotive batteries
(
page 503). Performing the tasks involved
incorrectly can cause damage to the vehicle
and impair the operating safety of the
vehicle, and/or cause severe injury to you
or others.
iWith a disconnected battery you will no
longer be able to turn the SmartKey in the
starter switch and pressing the KEYLESS-GO*
start/stop button will have no effect.
iIf your battery is discharged, the vehicle
must be jump started (
page 511) using the
jump start contacts in the engine compartment,
or an accessory battery charge unit* approved
by Mercedes-Benz must be connected using the
jump start contacts in the engine compartment
(see separate instructions for the accessory
battery charge unit*) before any of the following
steps can be performed. If the battery cannot be
jumped or charged, please contact an autho-
rized Mercedes-Benz Light Truck Center.


510 Practical hints
Battery
Connect the positive lead to the posi-
tive terminal and fasten it’s cover
(
page 509).
Connect the negative lead to the nega-
tive terminal (
page 509).
Charging the battery
If the battery is discharged, the battery can
be charged using the jump-start contacts
located in the engine compartment
(
page 512).
Charge the battery in accordance with
the instructions of the battery charger
manufacturer.
Batteries contain materials that can harm
the environment if disposed of improperly.
Large 12-volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!Never invert the terminal connections!
iThe following procedures must be carried
out following any interruption of battery power
(e.g. due to disconnection):

Set the clock (page 176).
Vehicles with COMAND system with naviga-
tion module*: Time and date are set auto-
matically.

Synchronize the door windows
(
page 244).

Synchronize the power tilt/sliding sunroof*
(
page 250).

Synchronize the power tilt/sliding panel*
(
page 255).

Synchronize the power folding exterior rear
view mirrors* (
page 204).
Warning!G
Never charge a battery while still installed in
the vehicle unless the accessory battery
charge unit approved by Mercedes-Benz is
being used. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.
An accessory battery charge unit specially
adapted for Mercedes-Benz vehicles and
tested and approved by Mercedes-Benz is
available, permitting the charging of the
battery in its installed position. Contact an
authorized Mercedes-Benz Light Truck
Center for information and availability.
Charge battery in accordance with the
separate instructions for the accessory
battery charger.