MERCEDES-BENZ R-Class 2012 W251 Owner's Manual

Lowering the vehicleGWARNING
Pump up the collapsible spare wheel before
lowering the vehicle. You could otherwise
damage the wheel rim.
XPlace the ratchet wrench onto the hexagon
nut of the jack so that the letters AB are
visible.XTurn the ratchet wrench until the vehicle is
once again standing firmly on the ground.XPlace the jack to one side.XTighten the wheel bolts evenly in a
crosswise pattern in the sequence
indicated ( : to A ). The tightening torque
must be 110 lb-ft (150 Nm) .GWARNING
Have the tightening torque checked
immediately after a wheel is changed. The
wheels could come loose if they are not
tightened to a torque of 110 lb/ft
(150 Nm) .
XTurn the jack back to its initial position and
store it together with the rest of the vehicle
tool kit in the cargo compartment.XTransport the defective wheel in the cargo
compartment.
or
XDepending on the size of the wheel, you
may also be able to secure the defective
wheel in the emergency spare wheel well.
In this case, you must remove the stowagetray from the emergency spare wheel well
and store it securely in the cargo
compartment.
For further information on stowing the
collapsible spare wheel, see ( Y page 298).
i When you are driving with the collapsible
spare wheel mounted, the tire pressure
loss warning system or the tire pressure
monitoring system cannot function
reliably. Only restart the tire pressure loss
warning system/tire pressure monitoring
system when the defective wheel has been
replaced with a new wheel.
Vehicles with tire pressure monitoring
system: all mounted wheels must be
equipped with functioning sensors and the
defective wheel should no longer be in the
vehicle.
MOExtended tires (tires with run-flat
properties)
MOExtended tires (tires with run-flat
properties) allow you to continue driving your
vehicle even if one or more tires are entirely
deflated.
MOExtended tires may only be used in
conjunction with the activated tire pressure
loss warning system or with the activated tire
pressure monitoring system.
The maximum permissible distance which
can be driven in run-flat mode depends on the
load in the vehicle. You can drive 50 miles
(80 km) if the vehicle is partially laden and
18 miles (30 km) if it is fully laden.
The maximum permissible distance which
can be driven in run-flat mode is counted from
the moment the tire pressure loss warning
appears in the multifunction display.
You must not exceed a maximum speed of
50 mph (80 km/h).
Flat tire309Breakdown assistanceZ

GWARNING
The handling characteristics of your vehicle
deteriorate in run-flat mode, for example:
R when cornering
R when braking
R when accelerating rapidly
Adapt your driving style accordingly and avoid
sudden changes in direction and sudden
acceleration, as well as driving over obstacles
(i.e. curbs, potholes), and driving off-road.
This is particularly the case when the vehicle
is heavily laden.
The maximum permissible distance that can
be driven in run-flat mode depends to a large
extent on the loads placed on the vehicle. It
can be shorter due to high speeds, a heavy
load, sudden changes in direction, the road
surface condition, outside temperature, etc.,
or further if you drive carefully and
conservatively.
Do not continue to drive in run-flat mode if:
R you hear banging noises.
R the vehicle starts to shake.
R you see smoke and smell rubber.
R ESP ®
is intervening constantly.
R there are tears in the sidewalls of the tire.
After driving in run-flat mode, you must have
the wheel(s) checked for damage at a
qualified specialist workshop which has the
necessary specialist knowledge and tools to
carry out the work required. The defective tire
must be replaced in every case.
Mercedes-Benz recommends that you use an
authorized Mercedes-Benz Center for this
purpose. In particular, work relevant to safety
or on safety-related systems must be carried
out at a qualified specialist workshop.
i When replacing one or all tires, make sure
that you only use tires marked
MOExtended and of the specified size for
the vehicle.
i Vehicles equipped with MOExtended tires
are not equipped with a TIREFIT kit at the
factory. It is therefore recommended that
you additionally equip your vehicle with a
TIREFIT kit if you mount tires that do not
feature run-flat properties, e.g. winter tires.
A TIREFIT kit can be obtained from an
authorized Mercedes-Benz Center.
Battery
Important safety notes
In order for the battery to achieve the
maximum possible service life, it must always
be sufficiently charged.
! Have the battery checked regularly at a
qualified specialist workshop, such as an
authorized Mercedes-Benz Center.
Adhere to the service intervals indicated in
the service booklet or ask a qualified
specialist workshop, such as an authorized
Mercedes-Benz Center.
Have the battery charge checked more
frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for
a lengthy period.
Only replace a battery with a battery that has
been recommended by Mercedes-Benz.
Consult an authorized Mercedes-Benz Center
if you wish to leave your vehicle parked for a
long period of time.
GWARNING
Comply with safety precautions and take
protective measures when handling batteries.
Risk of explosionFire, naked flames and
smoking are prohibited
when handling the battery.
Avoid creating sparks.Battery acid is caustic.
Avoid contact with the skin,
eyes or clothing.310BatteryBreakdown assistance

Wear suitable protective
clothing, in particular
gloves, an apron and a face
mask.
Immediately rinse acid
splashes off with clean
water. Consult a doctor if
necessary.Wear eye protection.Keep children away.Observe this Operator's
Manual.HEnvironmental noteBatteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and recycled to protect the
environment.Dispose of batteries in an
environmentally friendly
manner. Return discharged
batteries to a qualified
specialist workshop, e.g. an
authorized Mercedes-Benz
Center, or to a special
collection point for old
batteries.GWARNING
Failure to follow these instructions can result
in severe injury or death.
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.GWARNING
Do not place any metal objects on the battery
as this could result in a short circuit.
Use leak-proof batteries only to avoid the risk
of acid burns in the event of an accident.
Take care that you do not become statically
charged, e.g. by wearing synthetic clothing or
rubbing against textiles. For this reason, you
also should not pull or push the battery over
carpets or other synthetic materials.
Never touch the battery first. First, touch the
outside body of the vehicle in order to release
any possible electrostatic charges.
Do not rub the battery with rags or cloths. The
battery could explode if touched due to
electrostatic charge or due to spark
formation.
! Before working on the battery, e.g.
loosening the battery terminals, switch off
the engine and remove the SmartKey from
the ignition. On vehicles with KEYLESS-GO,
make sure that the ignition is switched off.
Check that all the indicator lamps in the
instrument cluster are off. You may
otherwise destroy electronic components,
such as the alternator.
! Like other batteries, the vehicle battery
may discharge over time if you do not use
the vehicle. In this case have the battery
checked at a qualified specialist workshop,
such as an authorized Mercedes-Benz
Center. You can also charge the battery
with a charger recommended by Mercedes-
Benz. Contact an authorized Mercedes-
Benz Center for more information.
Battery311Breakdown assistanceZ

The battery and the cover of the positive
terminal clamp must be installed securely
during operation.
i Remove the SmartKey if you park the
vehicle and do not require any electrical
consumers. The vehicle will then use very
little energy, thus conserving battery
power.
Mercedes-Benz recommends that you do not
carry out work on batteries yourself, e.g.
removing or charging. Always have this work
performed at a qualified specialist workshop,
e.g. an authorized Mercedes-Benz Center.
i If the power supply has been interrupted,
e.g. if the battery has been reconnected,
you must carry out the following tasks:
R set the clock ( Y page 206).
On vehicles with COMAND and a
navigation system, the clock is set
automatically.
R reset the sliding sunroof ( Y page 90).
R reset the panorama roof with power tilt/
sliding panel ( Y page 92).
R reset the function for automatically
folding the exterior mirrors in/out by
folding the mirrors out once
( Y page 110).
R reset the side windows ( Y page 89).
Charging the battery
GWARNING
Never charge a battery still installed in the
vehicle unless a battery charger unit approved
by Mercedes-Benz is being used. Gases may
escape during charging and cause explosions
that may result in paint damage, corrosion or
personal injury.
A battery charger unit specially adapted for
Mercedes-Benz vehicles and tested and
approved by Mercedes-Benz is available as an
accessory. It permits the charging of the
battery in its installed position. Contact an
authorized Mercedes-Benz Center for further
information and availability.
Charge the battery in accordance with the
separate instructions for the battery charger.GWARNING
There is a risk of acid burns during the
charging process due to the gases which
escape from the battery. Do not lean over the
battery during the charging process.
GWARNING
Battery acid is caustic. Avoid contact with the
skin, eyes or clothing.
! Only charge the installed battery with a
battery charger which has been tested and
approved by Mercedes-Benz. These battery
chargers allow the battery to be charged
while still installed.
! Only use battery chargers with a
maximum charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment ( Y page 313).
XOpen the hood ( Y page 282).XConnect the battery charger to the positive
terminal and earth point in the same order
as when connecting the donor battery in
the jump-starting procedure
( Y page 313).XRead the battery charger's operating
instructions before charging the battery.312BatteryBreakdown assistance

Jump-startingGWARNING
Failure to follow these directions will cause damage to the electronic components, and can lead
to a battery explosion and severe injury or death.
Never lean over batteries while connecting or jump starting. 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.
Attempting to jump start a frozen battery can result in it exploding, causing personal injury.
Read all instructions before proceeding.
! Avoid repeated and lengthy starting attempts. Otherwise, non-combusted fuel may
damage the catalytic converter 36
and create a risk of fire.
Do not use a rapid-charging device to start the engine.
Make sure the jumper cables are not damaged.
Make sure the jumper cables are not touching any other metal objects when they are
connected to the battery.
If your vehicle's battery is discharged, the engine can be jump-started from another vehicle
or from a second battery using jumper cables.
Observe the following points:
XThe battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or a jump-starting device.XOnly jump-start the vehicle when the engine is cold and the catalytic converter system has
cooled down 37
.XDo not start the engine if the battery is frozen. Let the battery thaw first.XJump-starting may only be performed from batteries with a nominal voltage of 12 V.XOnly use jumper cables which have a sufficient cross-section and insulated terminal clamps.XMake sure that the jumper cables cannot come into contact with parts, such as the pulley
or the fan. These parts move when the engine is started and while it is running.XIf the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
i Jumper cables and further information about jump-starting can be obtained from any
authorized Mercedes-Benz Center, for example.
XMake sure that the two vehicles do not touch.XApply the parking brake firmly.XShift the transmission to position P.36
Only vehicles with a gasoline engine.
37 Only vehicles with a gasoline engine.Jump-starting313Breakdown assistanceZ

XSwitch off all electrical consumers (e.g. radio, blower, etc.).XOpen the hood (Y page 282).
Position number C identifies the charged battery of the other vehicle or an equivalent jump-
starting device.
XLift up cover : of positive terminal ; in the direction of the arrow.XConnect positive terminal ; on your vehicle to positive terminal = of donor battery C
using the jumper cable, beginning with your own battery.XStart the engine of the donor vehicle and run it at idling speed.XRemove cover A from earth point B.XConnect negative terminal ? of donor battery C to earth point B of your vehicle using
the jumper cable, connecting the jumper cable to donor battery C first.XStart the engine.XAllow the engine to run for a few minutes before disconnecting the jumper cable.XFirst, remove the jumper cable from earth point B and negative terminal ?, then from
positive terminal ; and positive terminal =, each time disconnecting from the contacts
on your own vehicle first.XHave the battery checked at a qualified specialist workshop, e.g. an authorized Mercedes-
Benz Center. The jump-starting procedure is not a standard operating state; therefore, have
the battery checked.314Jump-startingBreakdown assistance

Towing and tow-starting
Important safety notes
GWARNING
If you tow the vehicle, you must use a rigid
towing bar if:
R the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force.
Before towing away, make sure that the
steering can be moved and is not locked.
If you tow or tow-start another vehicle, its
weight must not exceed the maximum
permissible gross vehicle weight of your
vehicle.
It is better to have the vehicle transported
than to have it towed.
! You may only tow the vehicle a maximum
distance of 30 miles (50 km). A towing
speed of 30 mph (50 km/h) must not be
exceeded.
For towing distances over 30 miles
(50 km), the vehicle must loaded onto a
transporter.
! Only secure the tow rope or tow bar at the
towing eyes. Otherwise, the vehicle could
be damaged.
! Do not use the towing eye for recovery,
as this could damage the vehicle. If in
doubt, recover the vehicle with a crane.
! When towing, pull away slowly and
smoothly. If the tractive power is too high,
the vehicles could be damaged.
! Do not tow with sling-type equipment.
This could damage the vehicle.
! When towing vehicles with KEYLESS-GO,
use the key instead of the Start/Stop
button. Otherwise, the automatic
transmission may shift to position P when
the driver's or front-passenger door are
opened, which could lead to damage to the
transmission.
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
If the vehicle has suffered transmission
damage, have it transported on a transporter
or trailer.
The automatic transmission must be in
position N when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 2 in
the ignition lock
R cannot shift the automatic transmission to
position N
i Before the vehicle is towed, switch off the
automatic locking feature ( Y page 208).
You could otherwise be locked out when
pushing or towing the vehicle.
Installing/removing the towing eye
Installing the towing eye
Vehicles with a trailer tow hitch: if possible
secure the towing device on the trailer tow
hitch ( Y page 191).
XRemove the towing eye from the vehicle
tool kit ( Y page 296).GWARNING
The exhaust tail pipe may be hot. You could
burn yourself if you touch the tail pipe. Be
particularly careful when removing the rear
cover.
The mountings for the removable towing eyes
are located in the bumpers. They are at the
front and at the rear, under the covers.
Towing and tow-starting315Breakdown assistanceZ

XPress the mark on cover : inwards in the
direction of the arrow.XTake cover : off the opening.XScrew the towing eye in clockwise to the
stop and tighten it.
Removing the towing eye
XLoosen the towing eye and unscrew it.XAttach cover : to the bumper and press
until it engages.XPlace the towing eye in the vehicle tool kit.
Towing a vehicle with both axles on
the ground
When having your vehicle towed, observe the
important safety notes ( Y page 315).
GWARNING
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will then need
much more effort to brake and steer the
vehicle. Adapt your style of driving
accordingly.
The automatic transmission automatically
shifts to position P when you open the driver's
or front-passenger door or when you remove
the SmartKey from the ignition lock. In order
to ensure that the automatic transmission
stays in position N when towing the vehicle,
you must observe the following points:XMake sure that the vehicle is stationary and
the SmartKey in the ignition lock is in
position 0.XTurn the SmartKey to position 2 in the
ignition lock.
On vehicles with KEYLESS-GO, use the key
instead of the Start/Stop button
( Y page 145).XDepress and hold the brake pedal.XShift the automatic transmission to
position N.XRelease the brake pedal.XRelease the parking brake.XLeave the SmartKey in position 2 in the
ignition lock.
Transporting the vehicle
The towing eyes or trailer tow hitch can be
used to pull the vehicle onto a trailer or
transporter if you wish to transport it.
XTurn the SmartKey to position 2 in the
ignition lock.XShift the automatic transmission to
position N.
As soon as the vehicle is loaded:
XPrevent the vehicle from rolling away by
applying the parking brake.XShift the automatic transmission to
position P.XTurn the SmartKey to position 0 in the
ignition lock and remove the SmartKey
from the ignition lock.XSecure the vehicle.
! Only lash the vehicle down by the wheels
or wheel rims, not by parts of the vehicle
316Towing and tow-startingBreakdown assistance

such as axle or steering components.
Otherwise, the vehicle could be damaged.
Notes for 4MATIC vehicles
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised,
as doing so will damage the transmission.
If the vehicle has transmission damage or
damage to the front or rear axle, have it
transported on a transporter or trailer.
In the event of damage to the electrical
system
If the battery is defective, the automatic
transmission will be locked in position P. To
shift the automatic transmission to position
N , you must provide power to the vehicle's
electrical system in the same way as when
jump-starting ( Y page 313).
Have the vehicle transported on a transporter
or trailer.
Recovering a vehicle that has become
stuck
! Pull away smoothly, slowly, and in a
straight line when pulling out a vehicle that
has become stuck. Excessive tractive
power could damage the vehicles.
If the drive wheels have become stuck in
loose or muddy ground, pull the vehicle out
with extreme caution, particularly if it is
laden.
Never attempt to recover a stuck vehicle with
a trailer attached.
Pull out the vehicle backwards, if possible
using the tracks it made when it became
stuck.
Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission
must not be started by tow-starting. This
could otherwise damage the transmission.
Fuses
Important safety notes
The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the
components on the circuit and their functions
stop operating.
GWARNING
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 Center.
Blown fuses must be replaced with fuses of
the same rating, which you can recognize by
the color and value. The fuse ratings are listed
in the fuse allocation chart. An authorized
Mercedes-Benz Center will be happy to
advise you.
i If a fuse has blown, contact a breakdown
service or an authorized Mercedes-Benz
Center.
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified
specialist workshop, e.g. an authorized
Mercedes-Benz Center.
! Only use fuses that have been approved
for Mercedes-Benz vehicles and which
have the correct fuse rating for the system
concerned. Otherwise, components or
systems could be damaged.
Before changing a fuse
XPark the vehicle and apply the parking
brake.XSwitch off all electrical consumers.XRemove the SmartKey from the ignition
lock.Fuses317Breakdown assistanceZ

The fuses are located in various fuse boxes:
R fuse box on the front-passenger side of the
dashboard
R fuse box in the engine compartment on the
right-hand side of the vehicle, when viewed
in the direction of travel
R fuse box in the stowage well under the
trunk floor
The fuse allocation chart is located in the
vehicle tool kit ( Y page 296) in the stowage
compartment under the trunk floor.
Dashboard fuse box
! Do not use a pointed object such as a
screwdriver to open the cover in the
dashboard. You could damage the
dashboard or the cover.
XTo open: pull cover : upwards in the
direction of the arrow and remove it.XTo close: clip in cover : on top of the
dashboard.XFold cover : inwards until it engages.
Fuse box in the engine compartment
XOpen the hood ( Y page 282).XRemove any existing moisture from the
fuse box using a dry cloth.XTo open: open clamp :.XFold up cover ; and remove it.
!
Make sure that no moisture can enter the
fuse box when the cover is open.
XTo close: check whether the seal is lying
correctly in cover ;.XInsert cover ; into the retainer at the front
of the fuse box.XFold down cover ; and close clamp :.
!
The cover must be positioned properly.
Moisture or dirt could otherwise impair the
operation of the fuses.
XClose the hood ( Y page 283).
Fuse box in the cargo compartment
XOpen the tailgate.318FusesBreakdown assistance