2012 MERCEDES-BENZ R-Class key

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

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

GWARNING
The tire pressure loss warning system does
not provide a warning for wrongly selected tire
inflation pressures. Always adjust tire
inflation pressure according to the Tire and
Loading Information placard on the driver's
door B-pillar or on the tire inflation pressure
label located on the inside of the fuel filler flap.
The tire pressure loss warning system does
not replace regular checks of the tire inflation
pressures since a gradual pressure loss in
more than one tire cannot be detected by the
tire pressure loss warning system.
The tire pressure loss warning system is not
able to issue a warning due to a sudden
dramatic loss of tire inflation pressure (e.g.
tire blowout caused by a foreign object). In
this case bring the vehicle to a halt by carefully
applying the brakes and avoiding abrupt
steering maneuvers.
The function of the tire pressure loss warning
system is limited or delayed if:
R snow chains are mounted to your vehicle's
tires.
R road conditions are wintry.
R you are driving on sand or gravel.
R you adopt a very sporty driving style
(cornering at high speeds or driving with
high rates of acceleration).
R you are towing a very heavy or large trailer.
R you are driving with a heavy load (in the
vehicle or on the roof).
Restarting the tire pressure loss
warning system
Restart the tire pressure loss warning system
if you have:
R changed the tire pressure
R changed the wheels or tires
R mount new wheels or tires
XBefore restarting, consult the Tire and
Loading Information placard on the
B-pillar on the driver's side or the tirepressure table on the inside of the fuel filler
flap to ensure the tire pressure in all four
tires is set correctly for the current
operating conditions.XObserve the notes in the section on tire
pressures ( Y page 325).GWARNING
The tire pressure loss warning system can
only give reliable warnings if you have set the
correct tire pressure.
If an incorrect tire pressure is set, these
incorrect values will be monitored.
A tire with insufficient pressure results in
vehicle instability when driving, thus
increasing the risk of an accident.
XMake sure that the SmartKey is in position
2 (Y page 145) in the ignition lock.XPress and hold the V or U button on
the multifunction steering wheel until the
standard display appears in the
multifunction display ( Y page 202).XPress the * or & button until the
Run Flat Indicator Active Menu: R-
Button message appears in the
multifunction display.XPress the reset button ( Y page 29) on the
instrument cluster.
The Restart Run Flat Indicator?
message appears in the multifunction
display.
If you wish to confirm the restart:
XPress the W button.
The Run Flat Indicator Restarted
message appears in the multifunction
display.
After a teach-in period, the tire pressure
loss warning system will monitor the set
tire pressures of all four tires.330Tire pressureWheels and tires

iIf the tire pressure monitor is
malfunctioning, it may take more than
10 minutes for the tire pressure warning
lamp to inform you of the malfunction by
flashing for 60 seconds and then remaining
lit.
When the malfunction has been rectified,
the tire pressure warning lamp goes out
after driving for a few minutes.
Information on tire pressures is displayed in
the multifunction display. After a few minutes
of driving, the current tire pressure of each
tire is shown in the multifunction display.
i The tire pressure values indicated by the
on-board computer may differ from those
measured at a gas station with a pressure
gauge. The tire pressures shown by the on-
board computer refer to those measured at
sea level. At high altitudes, the tire pressure
values indicated by a pressure gauge are
higher than those shown by the on-board
computer. In this case, do not reduce the
tire pressures.
i The operation of the tire pressure monitor
can be affected by interference from radio
transmitting equipment (e.g. radio
headphones, two-way radios) that may be
being operated in or near the vehicle.
i This device complies with Part 15 of the
FCC Rules. Operation is subject to the
following two conditions:
1. This device may not cause harmful
interference, and
2. this device must accept any interference
received, including interference that may
cause undesired operation.
Any unauthorized modification to this
device could void the user’s authority to
operate the equipment.Checking tire pressure electronicallyXMake sure that the SmartKey is in position
2 (Y page 145) in the ignition lock.XPress and hold the V or U button on
the multifunction steering wheel until the
standard display appears in the
multifunction display ( Y page 202).XPress and hold the & or * button
until the current tire pressure of each tire
is shown in the multifunction display.
If the vehicle has been parked for longer than
20 minutes, the Tire pressure
displayed after driving for several
minutes message appears in the display.
After a teach-in period, the tire pressure
monitor automatically recognizes new wheels
or new sensors. If a clear allocation of the tire
pressure values to the individual wheels is not
possible, the Tire Pressure Monitor
Active message is shown instead of the tire
pressure display. The tire pressures are
already being monitored.
i If a spare wheel/emergency spare wheel
is mounted, the system may continue to
show the tire pressure of the wheel that has
been removed for a few minutes. If this
occurs, note that the value displayed for
the position where the spare tire is
mounted is not the same as the spare
wheel/emergency spare wheel's current
tire pressure.
Tire pressure monitor warning
messages
If the tire pressure monitor detects a
significant pressure loss on one or more tires,
a warning message is shown in the
multifunction display. A warning tone also
sounds and the tire pressure warning lamp
lights up in the instrument cluster.
Each tire that is affected by a significant loss
of pressure is highlighted with a color.
If the Tire Pressure(s) Please Correct
[bar] message appears in the multifunction
display:
332Tire pressureWheels and tires

XCheck the tire pressure on all four wheels
and correct it if necessary.
i If the wheel positions on the vehicle are
interchanged, the tire pressures may be
displayed for the wrong positions for a
short time. This is rectified after a few
minutes of driving, and the tire pressures
are displayed for the correct positions.
Restarting the tire pressure monitor
GWARNING
It is the driver's responsibility to set the tire
pressure to the recommended cold tire
pressure. Underinflated tires affect the ability
to steer or brake the vehicle. You might lose
control over the vehicle.
When you restart the tire pressure monitor,
all existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tire pressures as the
reference values for monitoring.
The tire pressure monitor must be restarted
when you set the tire pressure to a new value
(as a result of changed drive or load
characteristics, for example). The tire
pressure monitor then monitors the new tire
pressure values.
Restart the tire pressure monitor after you
have set the tire pressure to the value
recommended for the desired driving
situation ( Y page 325). Only correct tire
pressures on cold tires. Comply with the
recommended tire pressures on the tire and
loading information table on the B-pillar on
the driver's side. Additional tire pressure
values for driving at high speeds or with heavy
loads can be found in the tire pressure table
on the inside of the fuel filler flap.
XMake sure that the tire pressure is correct
on all four wheels.XMake sure that the SmartKey is in position
2 in the ignition lock.XPress and hold the V or U button on
the multifunction steering wheel until thestandard display appears in the
multifunction display ( Y page 202).XPress and hold the & or * button
until the tire pressure of each wheel or the
Tire pressure displayed after
driving for a few minutes message
appears.XPress the reset button on the instrument
cluster ( Y page 29).
The Restart tire pressure
monitor? message appears in the
multifunction display.
If you wish to confirm the restart:
XPress the W button.
The Tire Pressure Monitor
Restarted message appears in the
multifunction display.
After driving for a few minutes, the system
checks whether the current tire pressures
are within the specified range. The new tire
pressures are then accepted as reference
values and monitored.
If you wish to cancel the restart:
XPress the X button.
The tire pressure values stored at the last
restart will continue to be monitored.
Loading the vehicle
Instruction labels for tires and loads
GWARNING
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Loading the vehicle333Wheels and tiresZ