2008 MERCEDES-BENZ R320 key

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.

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.

513 Practical hints
Towing the vehicle
Towing the vehicle
Mercedes-Benz recommends that the
vehicle be transported with all wheels off
the ground using flatbed or appropriate
wheel lift/dolly equipment. This method is
preferable to other types of towing.If circumstances do not permit the recom-
mended towing methods, the vehicle may
be towed with all wheels on the ground
only so far as necessary to have the vehicle
moved to a safe location where the recom-
mended towing methods can be employed.
When towing the vehicle with all wheels on
the ground, the vehicle may be towed only
for distances up to 30 miles (50 km) and at
a speed not to exceed 30 mph (50 km/h).
!Do not tow-start the vehicle.
!Use flatbed or wheel lift/dolly equipment,
with the SmartKey in starter switch turned to
position0.
Do not tow with sling-type equipment. Towing
with sling-type equipment over bumpy roads will
damage radiator and supports.
To prevent damage during transport, do not tie
down vehicle by its chassis or suspension parts.
Use the towing eyes.
Switch off the ESP
® (page 104) and the
automatic central locking (
page 126).
!Do not tow with one axle raised. Doing so
could damage the transfer case, which is not
covered by the Mercedes-Benz Limited
Warranty.
All wheels must be on or off the ground. Observe
instructions for towing the vehicles with all
wheels on the ground.
Warning!G
If circumstances require towing the vehicle
with all wheels on the ground, always tow
with a tow bar if

the engine will not run

there is a malfunction in the brake
system

there is a malfunction in the power
supply or in the vehicle’s electrical
system
as that will be necessary to adequately
control the vehicle.
Prior to towing the vehicle with all wheels on
the ground, make sure the automatic trans-
mission is in neutral positionN.

514 Practical hints
Towing the vehicle
If you want the gear position to remain in
neutral positionN, 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.
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
vehicle. Adapt your driving accordingly.
!When towing the vehicle with all wheels on
the ground, the automatic transmission must be
in neutral positionN.
If you turn off the engine

using the SmartKey and

remove the SmartKey from the starter
switch
or

open a front door

or when using the KEYLESS-GO* start/stop
button and open a front door
the automatic transmission will shift to park
positionP automatically.
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.

515 Practical hints
Towing the vehicle
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.
Installing towing eye bolt
Depending on whether you are towing a
vehicle or you are being towed, the towing
eye bolt can be screwed into threaded
holes which are located behind covers on
the right-hand side of each bumper.
Example illustration R 550 4MATIC
1Towing eye cover
!Towing of the vehicle should only be done
using the properly installed towing eye bolt.
Never attach a tow cable, tow rope or tow rod to
the vehicle chassis, frame or suspension parts.
iTo signal turns while being towed with
hazard warning flasher in use, set the starter
switch to position2 and activate combination
switch for left or right turn signal in usual manner
– only the selected turn signal will operate.
Upon canceling the turn signal, the hazard warn-
ing flasher will operate again.

518 Practical hints
Fuses
The electrical fuses in your vehicle serve to
switch off malfunctioning power circuits.
If a fuse is blown, the components and
systems secured by that fuse will stop
operating.If a newly inserted fuse blows again, have
the cause determined and rectified by an
authorized Mercedes-Benz Light Truck
Center.
A fuse chart explains the fuse allocation
and fuse amperages. It is located in the
cargo compartment with the vehicle tool
kit (
page 469).
The electrical fuses are located in different
fuse boxes:

on the passenger side of the engine
compartment (
page 519)

in the cargo compartment
(
page 519)

in the passenger compartment
(
page 520)Before replacing fuses:
Apply the parking brake (page 65).
Make sure automatic transmission is
set to position P (
page 192).
The gear position indicator in the
multifunction display should be on
P.
Turn off all electrical consumers.
Turn off the engine (page 66).
Remove the SmartKey from the starter
switch.
Vehicles with KEYLESS-GO*:
Open the driver’s door (this puts
the starter switch to position0,
same as with the SmartKey re-
moved from starter switch). The
driver’s door can then be closed
again.
Warning!G
Only use fuses approved by Mercedes-Benz
with the specified amperage for the system
in question and do not attempt to repair or
bridge a blown fuse. Using other than
approved fuses or using repaired or bridged
fuses may cause an overload leading to a
fire, and/or cause damage to electrical
components and/or systems. Have the
cause determined and remedied by an
authorized Mercedes-Benz Light Truck
Center
iA blown fuse must be replaced by an appro-
priate spare fuse (recognizable by its color or the
fuse rating given on the fuse) of the amperage
recommended in the fuse chart.
Any Mercedes-Benz Light Truck Center will be
glad to advise you on this subject.