MERCEDES-BENZ R320 2008 W251 Owner's Manual

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.


501 Practical hints
Flat tire
Lowering the vehicle
Vehicles with scissors-type jack:
Attach ratchet to vehicle jack in such a
way that the wordDOWN can be seen.
Lower the vehicle until it is resting fully
on its own weight:
Vehicles with screw-type jack:
Turn crank counterclockwise.
Vehicles with scissors-type jack:
Turn ratchet in directionDOWN.
Remove the jack.1-5Wheel bolts
6Wheel wrench
Tighten the five wheel bolts evenly,
following the diagonal sequence
illustrated (1to5), until all bolts
are tight. Observe a tightening torque
of 110 lb-ft (150 Nm).
Store jack and all other vehicle tool kit
items back into the storage well.
Warning!G
Inflate collapsible tire only after the wheel is
properly mounted.
Inflate the collapsible tire using the electric
air pump (
page 499) before lowering the
vehicle.
Warning!G
Have the tightening torque checked after
changing a wheel. The wheels could come
loose if they are not tightened to a torque of
110 lb-ft (150 Nm).
iThe removed road wheel cannot be stored in
the spare wheel well under the cargo compart-
ment floor, but should be transported in the
cargo compartment wrapped in a protective
wrap.
Vehicles with TPMS or Advanced TPMS*:
Do not activate the tire inflation pressure moni-
tor until a full size wheel/tire with functioning
sensor has been placed back into service on the
vehicle.

502 Practical hints
Bleeding the fuel system (diesel engine only)
Driving the vehicle until the fuel tank is
empty is not recommended. Otherwise, air
may be sucked into the fuel system. If this
happens, the? malfunction indicator
lamp (USA only) or the ± malfunction
indicator lamp (Canada only) comes on
and the engine may not start immediately
after refueling the vehicle.
After refueling:
Make sure the automatic transmission
is set toP.
The gear position indicator in the multi-
function display should be on
P.
Do not depress the accelerator.
Turn the SmartKey in the starter switch
to position 2 for at least 10 seconds
(
page 40).
Return the SmartKey in the starter
switch to position 0 (
page 40).
Turn the SmartKey in the starter switch
to position 3 (
page 41) and hold it
there for a maximum of 40 seconds or
until the engine runs surge-free.
If the engine does not start:
Wait for approximately 2 minutes.
Turn the SmartKey in the starter switch
to position 3 (
page 41) and hold it
there for a maximum of 40 seconds or
until the engine runs surge-free.
If the engine still does not start, do not
make any further attempts to start the
engine. Contact an authorized
Mercedes-Benz Light Truck Center or call
Roadside Assistance (
page 325).iVehicles with KEYLESS-GO*: If necessary,
remove the KEYLESS-GO start/stop button from
the starter switch (
page 41).iWhen the? malfunction indicator lamp
(USA only) or the ± malfunction indicator
lamp (Canada only) has been illuminated for the
above condition, it will remain illuminated until
the engine was cycled on and off four times in a
row.

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.


506 Practical hints
Battery
Switch off all electrical consumers.
Read and observe safety instructions
and precautions (
page 503).
Open the front passenger door.
Move the front passenger seat to the
most rearward position (
page 45).Step 2 (Disconnecting)
1Seat rail cover, front right
2Seat rail cover, front left
Pull off right seat rail cover 1 in direc-
tion of arrow.
Pull left seat rail cover 2 in direction
of arrow as far as it will go.
Left seat rail cover 2 cannot be re-
moved.3Battery cover mounting nuts
Using a 6 mm T-handle hex key (not
supplied with vehicle) with a minimum
shaft length of 12 in (30 cm), unfasten
and remove battery cover mounting
nuts 3 located at the floor carpet per-
foration.
Move the front passenger seat to the
most forward position (
page 45).
iIf the vehicle battery is discharged and you
had the vehicle jump started:

Leave the engine running.

Complete step 1, starting with switching off
all electrical consumers.

Continue with step 2.

When the font passenger seat is in the most
forward position, turn off the engine.
iOpen doors only when conditions are safe to
do so.


507 Practical hints
Battery
Switch off the ignition (page 40).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Make sure the vehicle’s on-board
electronics have status 0.
After turning off the engine with the
KEYLESS-GO start/stop button,
with the driver’s door closed, the
starter switch is in position1.
With the driver’s door opened, the
starter switch is set to position0,
same as SmartKey removed from
starter switch (
page 41).Step 3 (Disconnecting)
4Seat rail, rear
5Seat rail cover, rear
Pull seat rail cover 5 away from seat
rail 4 on both sides as indicated by
arrows.
Pull off seat rail cover 5 to the rear as
indicated by arrow.Step 4 (Disconnecting)
6Floor carpet
Pull back and fold floor carpet6 in
direction of the arrow.
iIf the vehicle battery is discharged and you
had the vehicle jump started, turn off the engine.
iTo release the floor carpet perforations (see
dotted line in above illustration), you will have to
apply somewhat greater force when pulling the
floor carpet back.

508 Practical hints
Battery
Step 5 (Disconnecting)
7Battery cover mounting nuts
Unfasten and remove battery cover
mounting nuts 7.Step 6 (Disconnecting)
8Battery cover with integrated air
channel
9Pulling battery cover out
aLifting battery cover
Lift battery cover 8 slightly in direc-
tion of arrow a.
Pull battery cover 8 in direction of
arrow 9.
Remove battery cover 8.Step 7 (Disconnecting)
bBattery ventilation hose
cBattery
dBattery attachment
eAttachment nuts
Pull battery ventilation hose b out of
battery c.
Unfasten and remove attachment
nutse.
Remove battery attachment d.
Push battery c to the left.

509 Practical hints
Battery
Step 8 (Disconnecting)
fPositive terminal with cover
gNegative terminal
Disconnect battery negative lead from
negative terminal g.
Make sure the negative lead does not
come into contact with the positive
lead.
Remove the cover from positive
terminal f.
Disconnect battery positive lead from
positive terminal f.Step 9 (Removing)
Take out battery.
Step 10 (Reinstalling)
Insert battery into the well under the
passenger seat.
Battery, shown removed for illustration
bBattery ventilation hose
hVent plug
Carry out step 11 (page 509) to
reconnect the battery .
Carry out steps 7 through 1 in reverse
order to completely reinstall the bat-
tery, (
page 508) to (page 505).
Step 11 (Reconnecting)
If the battery has been removed, carry
out step 10 (
page 509) before start-
ing the connecting procedure.
Open the driver’s door.
Make sure the SmartKey is removed
from the starter switch.
Vehicles with KEYLESS-GO*:
Make sure the vehicle’s on-board
electronics have status 0.
With the driver’s door opened, the
vehicle’s on-board electronics
have status 0, same as SmartKey
removed from the starter
switch (
page 41).!The battery, battery ventilation hoseb,
and vent plug h must always be securely
installed when the vehicle is in operation.