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

SeatFolding down the 2nd row of
seats .............................................. 254
Important safety notes ....................97
Resetting the 2nd row of seats ......256
Resetting the 3rd row of seats ....... 256
Seat belts
Adjusting the driver's and front-
passenger seat belt .........................54
Adjusting the height ......................... 54
Belt force limiters ............................ 55
Cleaning ......................................... 293
Correct usage .................................. 52
Emergency Tensioning Devices ........ 55
Fastening ......................................... 53
Important safety guidelines .............51
Releasing ......................................... 54
Safety guidelines ............................. 39
Special seat belt retractor ...............58
Switching belt adjustment on/off
(on-board computer) ......................209
Warning lamp ................................. 238
Warning lamp (function) ................... 54
Seats
Adjusting (electrically) .....................98
Adjusting (second and third rows) . 101
Adjusting the 4-way lumbar
support .......................................... 105
Adjusting the head restraint ............99
Cleaning the cover .........................293
Correct driver's seat position ........... 96
Folding down the 3rd row of seats . 255
Folding the rear bench seat
forwards/back ............................... 253
Multicontour seat .......................... 105
Seat heating problem ....................106
Seat ventilation problem ................107
Storing settings (memory
function) ........................................ 112
Switching seat heating on/off .......106
Switching the seat ventilation on/
off .................................................. 106
Securing hooks .................................. 258
Sensors (cleaning instructions) ....... 291
Service see ASSYST PLUS service interval
display Service interval display
Displaying service messages .........287
Hiding service messages ...............287
Notes ............................................. 287
Service messages ..........................287
Service products
Brake fluid ..................................... 359
Capacities ...................................... 355
Coolant (engine) ............................ 359
DEF special additives .....................357
Engine oil ....................................... 358
Fuel ................................................ 356
Important safety notes ..................354
Refrigerant (air-conditioning
system) .......................................... 359
Washer fluid ................................... 360
Settings
Factory (on-board computer) .........205
On-board computer .......................205
Setting the air distribution ............... 138
Setting the airflow ............................ 138
Side impact air bag ............................. 42
Side marker lamp (display
message) ............................................ 224
Side marker lamps (changing
bulbs) ................................................. 123
Side windows Convenience closing feature ............88
Convenience opening feature ..........87
Hinged side windows .......................87
Important safety information ...........86
Opening/closing .............................. 86
Problem (malfunction) .....................89
Resetting ......................................... 89
Sliding sunroof
Important safety notes ....................89
Opening/closing .............................. 90
Problem (malfunction) .....................92
Resetting ......................................... 90
see Panorama roof with power
tilt/sliding panel
SmartKey
Changing the battery .......................76
Changing the programming .............75
Checking the battery .......................76
Convenience closing feature ............88
Convenience opening feature ..........87
Display message ............................ 236Index15

be replaced and their anchoring points must
also be checked.
Only use seat belts which have been approved
by Mercedes-Benz.
Do not make any modifications to the seat
belts. This can lead to unintended activation
of the ETDs or to their failure to activate when
necessary.
Do not bleach or dye seat belts as this may
severely weaken them. In a crash they may
not be able to provide adequate protection.
Have all work carried out only by qualified
technicians. Contact an authorized
Mercedes-Benz Center.
Correct use of the seat beltsGWARNING
USE SEAT BELTS PROPERLY
R Seat belts can only work when used
properly. Never wear seat belts in any other
way than as described in this section, as
that could result in serious injuries in the
event of an accident.
R Each occupant should wear their seat belt
at all times, because seat belts help reduce
the likelihood of and potential severity of
injuries in accidents, including rollovers.
The integrated restraint system includes
SRS (driver front air bag, front-passenger
front air bag, side impact air bags, window
curtain air bags for the side windows),
Emergency Tensioning Devices, seat belt
force limiters, and front seat knee bolsters.
The system is designed to enhance the
protection offered to properly belted
occupants in certain frontal (front air bags
and ETDs) and side (side impact air bags,
window curtain air bags, and ETDs) impacts
which exceed preset deployment
thresholds and in certain rollovers (window
curtain air bags and ETDs).
R Never wear the shoulder belt under your
arm, across your neck or off your shoulder.
In a frontal crash, your body would move
too far forward. That would increase the
chance of head and neck injuries. The seat
belt would also apply too much force to the
ribs or abdomen, which could severely
injure internal organs such as your liver or
spleen.
Adjust the seat belt so that the shoulder
section is located as close as possible to
the middle of the shoulder. It should not
touch the neck. Never pass the shoulder
portion of the seat belt under your arm. For
this purpose, you can adjust the height of
the seat belt outlet.
R Position the lap belt as low as possible on
your hips and not across the abdomen. If
the lap belt is positioned across your
abdomen, it could cause serious injuries in
a crash.
R Never wear seat belts over rigid or
breakable objects in or on your clothing,
such as eyeglasses, pens, keys etc., as
these might cause injuries.
R Make sure the seat belt is always routed
snugly. Take special care of this when
wearing loose clothing.
R Never use a seat belt for more than one
person at a time. Do not fasten a seat belt
around a person and another person or
other objects at the same time.
R Seat belts should not be worn twisted. In a
crash, you would not have the full width of
the seat belt to distribute impact forces.
The twisted seat belt against your body
could cause injuries.
R Pregnant women should also always use a
lap-shoulder belt. The lap belt portion
should be positioned as low as possible on
the hips to avoid any possible pressure on
the abdomen.
R Place the seat backrest in a position that is
as upright as possible.
R Check your seat belt during travel to make
sure it is properly positioned.
R Never place your feet on the instrument
panel, dashboard, or on the seat. Always52Occupant safetySafety

keep both feet on the floor in front of the
seat.
R When using a seat belt to secure infant
restraints, toddler restraints, or children in
booster seats, always follow the child seat
manufacturer's instructions.GWARNING
Do not pass seat belts over sharp edges. They
could tear.
Do not allow the seat belt to get caught in the
door or in the seat adjustment mechanism.
This could damage the seat belt.
Never attempt to make modifications to seat
belts. This could impair the effectiveness of
the seat belts.
Fastening seat belts
GWARNING
According to accident statistics, children are
safer when properly restrained on the rear
seats than on the front-passenger seat. Thus,
we strongly recommend that children be
placed in the rear seat whenever possible.
Regardless of seating position, children 12
years old and under must be seated and
properly secured in an appropriately sized
child restraint system or booster seat
recommended for the size and weight of the
child. For additional information, see the
"Children in the vehicle" section.
A child's risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and/
or the child is not properly secured in the child
restraint.
XAdjust the seat and move the backrest to
an almost vertical position ( Y page 96).XPull the seat belt smoothly through belt
sash guide :.XWithout twisting it, guide the shoulder
section of the seat belt across the middle
of your shoulder and the lap section across
your hips.XEngage belt tongue ; in buckle =.
Seat-belt adjustment: if necessary, the
driver's and front-passenger seat belts
automatically adjust to the upper body
( Y page 54).XIf necessary, adjust the seat belt to the
appropriate height ( Y page 54).XIf necessary, pull upwards on the shoulder
section of the seat belt to tighten the belt
across your body.
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor to
securely fasten child restraint systems in the
vehicle. For further information on special
seat belt retractors, see ( Y page 58).
Occupant safety53SafetyZ

For more information about releasing the seat
belt with release button ?, see "Releasing
seat belts" ( Y page 54).
Seat belt adjustment
The seat-belt adjustment function adjusts the
driver's and front-passenger seat belt to the
upper body of the occupants.
The belt strap is tightened slightly when:
R you engage the belt tongue in the belt
buckle and you then turn the SmartKey to
position 2 in the ignition lock.
R the SmartKey is in position 2 in the ignition
lock and you then engage the belt tongue
in the buckle.
The seat-belt adjustment will apply a
retraction force if any slack is detected
between the occupant and the seat belt. Do
not hold on to the seat belt tightly while it is
adjusting. You can switch the seat-belt
adjustment on and off in the on-board
computer ( Y page 209).
The seat-belt adjustment is an integral part of
the PRE-SAFE ®
convenience function. More
information about PRE-SAFE ®
can be found
in the "PRE-SAFE ®
(preventative occupant
protection)" section ( Y page 49).
Belt height adjustment
You can adjust the seat belt height on the
driver's seat and the front-passenger seat.
Adjust the height so that the upper part of the
seat belt is routed across the center of your
shoulder.
XTo raise: slide the belt sash guide upwards.
The belt sash guide engages in various
positions.XTo lower: press and hold belt sash guide
release :.XSlide the belt sash guide downwards.XRelease belt sash guide release : and
make sure that the belt sash guide has
engaged.
Releasing seat belts
XPress release button ?(Y page 53) and
guide belt tongue ; back towards belt
sash guide :.
!
Make sure that the seat belt is fully rolled
up. Otherwise, the seat belt or belt tongue
will be trapped in the door or in the seat
mechanism. This could damage the door,
the door trim panel and the seat belt.
Damaged seat belts can no longer fulfill
their protective function and must be
replaced. Consult an authorized Mercedes-
Benz Center.
Belt warning for the driver and front
passenger
Regardless of whether the driver and front
passenger have fastened their seat belts
already, the 7 seat belt warning lamp
lights up for 6 seconds after every engine
start. It then goes out if the driver and the
front passenger have fastened their seat
belts.
If the driver's seat belt is not fastened after
the engine is started, an additional warning
tone will sound. The warning tone goes out
after approximately six seconds or once the
driver's seat belt is fastened.
54Occupant safetySafety

Children can be killed or seriously injured by
an inflating air bag. Note the following
important information when circumstances
require you to place a child in the front-
passenger seat:
R Your vehicle is equipped with air bag
technology designed to deactivate the
front-passenger front air bag in your vehicle
when the system senses the weight of a
typical 12-month-old child or less along
with the weight of a standard appropriate
child restraint on the front-passenger seat.
R A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates in a collision which
could occur under some circumstances,
even with the air bag technology installed
in your vehicle. The only means to eliminate
this risk completely is never to place a child
in a rear-facing child restraint in the front-
passenger seat. We therefore strongly
recommend that you always place a child
in a rear-facing child restraint on the rear
seat.
R If you install a rear-facing child restraint on
the front-passenger seat, make sure the
42 indicator lamp is
illuminated, indicating that the front-
passenger front air bag is deactivated.
Should the 42 indicator lamp
not illuminate or go out while the restraint
is installed, please check installation.
Periodically check the 42
indicator lamp while driving to make sure
the 42 indicator lamp is
illuminated. If the 42 indicator
lamp goes out or remains out, do not
transport a child on the front-passenger
seat until the system has been repaired.
A child in a rear-facing child restraint on the
front-passenger seat will be seriously
injured or even killed if the front-passenger
front air bag inflates.R If you place a child in a forward-facing child
restraint on the front-passenger seat:
- move the seat as far back as possible
- use the proper child restraint
recommended for the age, size and
weight of the child
- secure child restraint with the vehicle's
seat belt according to the child seat
manufacturer's instructions
R For children larger than a typical 12-month-
old child, the front-passenger front air bag
can be activated or deactivated.GWARNING
Infants and small children should never share
a seat belt with another occupant. During an
accident, they could be crushed between the
occupant and seat belt.
A child's risk of serious or fatal injuries is
significantly increased if the child restraints
are not properly secured in the vehicle and/
or the child is not properly secured in the child
restraint.
Children too big for a toddler restraint must
ride in seats using regular seat belts. Position
the shoulder belt across the chest and
shoulder, not face or neck. A booster seat
may be necessary to achieve proper seat belt
positioning for children over 41 lb (18 kg) until
they reach a height where a lap/shoulder belt
fits properly without a booster.
When the child restraint is not in use, remove
it from the vehicle or secure it with the seat
belt to prevent the child restraint from
becoming a projectile in the event of an
accident.
If an infant or child is traveling in the vehicle:
XSecure the infant or child with an
appropriate infant or child restraint
recommended for the child's age and
weight.XMake sure that the infant or child is
properly secured at all times while the
vehicle is in motion.Children in the vehicle57SafetyZ

GWARNING
When leaving the vehicle, always remove the
SmartKey from the ignition lock. Always take
the SmartKey with you and lock the vehicle.
Do not leave children unattended in the
vehicle, even if they are secured in a child
restraint system, or with access to an
unlocked vehicle. A child's unsupervised
access to a vehicle could result in an accident
and/or serious personal injury. The children
could:
R injure themselves on parts of the vehicle
R be seriously or fatally injured through
excessive exposure to extreme heat or cold
R injure themselves or cause an accident with
vehicle equipment that can be operated
even if the SmartKey is removed from the
ignition lock or removed from the vehicle,
such as seat adjustment, steering wheel
adjustment, or the memory function
If children open a door, they could injure other
persons or get out of the vehicle and injure
themselves or be injured by following traffic.
Do not expose the child restraint system to
direct sunlight. The child restraint system's
metal parts, for example, could become very
hot, and the child could be burned on these
parts.
GWARNING
Do not carry heavy or hard objects in the
passenger compartment or trunk unless they
are firmly secured in place.
Unsecured or improperly positioned cargo
increases a child's risk of injury in the event
of
R strong braking maneuvers
R sudden changes of direction
R an accident
Special seat belt retractor
All seat belts except the driver's seat belt are
equipped with a special seat belt retractor.
When activated, the special seat belt
retractor ensures the seat belt will not
slacken once the child restraint system has
been secured.
Installing a child restraint system:XAlways comply with the manufacturer's
installation instructions.XPull the seat belt smoothly from the inertia
reel.XEngage the seat belt tongue in the belt
buckle.
Activating the special seat belt retractor:
XPull the seat belt out fully and let the inertia
reel retract it again.
While the seat belt is retracting, you should
hear a ratcheting sound. The special seat
belt retractor is enabled.XPush down on the child restraint system to
take up any slack.
Removing a child restraint system/
deactivating the special seat belt retractor:
XAlways comply with the manufacturer's
installation instructions.XPress the seat belt release button and
guide the belt tongue to the belt outlet.
The special seat belt retractor is
deactivated.GWARNING
Never release the seat belt buckle while the
vehicle is in motion, since the special seat belt
retractor will be deactivated.
LATCH-type (ISOFIX) child seat anchors
in the rear
GWARNING
Children that are too large for a child restraint
must travel in seats using normal seat belts.
Position shoulder belt across the chest and
shoulder, not face or neck.
In order to attain the correct seating position
for children weighing over 41 lb (18 kg), it may
be necessary to use a booster seat until they
reach a height where a normal lap/shoulder
58Children in the vehicleSafety

injury to the head and neck in the event of an
accident or similar situation.
Do not drive the vehicle without the seat head
restraints. Head restraints are intended to
help reduce injuries during an accident.
! To avoid damage to the seats and the seat
heating, observe the following information:
R keep liquids from spilling on the seats. If
liquid is spilled on the seats, dry them as
soon as possible.
R if the seat covers are damp or wet, do not
switch on the seat heating. The seat
heating should also not be used to dry
the seats.
R clean the seat covers as recommended;
see the "Interior care" section.
R do not transport heavy loads on the
seats. Do not place sharp objects on the
seat cushions, e.g. knives, nails or tools.
The seats should only be occupied by
passengers, if possible.
R when the seat heating is in operation, do
not cover the seats with insulating
materials, e.g. blankets, coats, bags,
seat covers, child seats or booster seats.
! When you move the seats, make sure that
there are no objects in the footwell or
behind the seats. Otherwise, you could
damage the seats and the objects.
! When the outer seats in the second row
are folded down, the front seats must not
be in their rearmost position. The front
seats and the outer seats in the second row
could otherwise be damaged.
! Make sure that the sun visor is folded up
before adjusting the backrest and head
restraint height. The head restraint and sun
visor could otherwise collide when the head
restraint is fully extended.
i The rear-compartment head restraints
can be removed ( Y page 100).Please contact an authorized Mercedes-
Benz Center for more information.
i Other topics:
R Cargo compartment enlargement
(folding the second and third row of seats
forward) ( Y page 253)
Adjusting the seats
i Vehicles without Memory function: the
seats can be adjusted within three minutes
of a front door being opened.
The time period starts over again if, within
these three minutes, you:
R open or close a front door
R insert the SmartKey into the ignition lock
or remove it from the ignition lock
R switch the ignition on or off
If the SmartKey is in position 2 in the
ignition lock, the seats can be adjusted at
any time.
:Head restraint height 7;Backrest angle=Seat fore-and-aft adjustment?Seat cushion angleASeat height
i
Vehicles with Memory function: If PRE-
SAFE ®
has been activated, the front-
passenger seat is moved to a better
position if it was previously set unfavorably.
7 Only for vehicles with memory function.98SeatsSeats, steering wheel and mirrors

iYou can store the seat settings using the
memory function ( Y page 112).
Adjusting the head restraints
Adjusting the head restraints manually
Adjusting the head restraint height 8
! The head restraints must only be removed
at a qualified specialist workshop.
Mercedes-Benz recommends that you use
a Mercedes-Benz Center for this purpose.
XIf the head restraint is fully lowered, it is
necessary to press release catch :.XTo raise: pull the head restraint up to the
desired position.XTo lower: press release catch : in the
direction of the arrow and push the head
restraint down to the desired position.
Adjusting the angle of the head restraints
GWARNING
Vehicles with Rear Seat Entertainment
System: When adjusting the head restraint,
make sure your fingers do not become caught
between the head restraint cushion and the
monitor. Failing to do so may lead to injury.
XPush or pull the lower edge of the head
restraint in the direction of the arrow.
Adjusting the head restraint height
electrically 9
XTo adjust the head restraint height:
slide
the switch for head restraint adjustment
( Y page 98) up or down in the direction of
the arrow.
Adjusting luxury head restraints
GWARNING
When folding back the side cushions, never
reach between the side cushion and the
mounting post. You could otherwise be
trapped.
XTo adjust the side bolsters of the head
restraint: push or pull right and/or left-8
For vehicles without memory function only.
9 For vehicles with memory function only.Seats99Seats, steering wheel and mirrorsZ

hand side bolster : into the desired
position.XTo adjust the angle of the head
restraint: push or pull the head restraint in
the direction of arrow ;.
Rear seat head restraints
GWARNING
For safety reasons, always drive with the rear
head restraints in the upright position when
the rear seats are occupied.
Keep the area around head restraints clear of
articles (e.g. clothing) to not obstruct the
folding operation of the head restraints.
GWARNING
For your protection, drive only with properly
positioned head restraints.
Adjust the head restraint in such a way that it
is as close to the head as possible and the
center of the head restraint supports the back
of the head at eye level. This will reduce the
potential for injury to the head and neck in the
event of an accident or similar situation.
With a rear seat occupied, make sure to move
the respective head restraint up from the
lowest non-use position and have the
occupant adjust the head restraint properly.
Do not drive the vehicle without the seat head
restraints installed when the rear seats are
occupied. Head restraints are intended to
help reduce injuries during an accident.
Adjusting the head restraint height
(second and third row of seats)
Outer seat head restraints in the second row of
seats
Outer seat head restraints in the third row of seats
XIf the head restraint is fully lowered, it is
necessary to press release catch :.XTo raise: pull the head restraint up to the
desired position.XTo lower: press release catch : and push
the head restraint down until it is in the
desired position.
Removing and installing rear head
restraints
GWARNING
Occupants should only travel sitting on seats
which have the head restraints installed. In
the event of an accident, this reduces the risk
of injury for passengers seated in the rear
compartment.
If you wish to remove the head restraints from
the outer seats in the second row of seats,
100SeatsSeats, steering wheel and mirrors

Adjusting seat fore-and-aft adjustment
(outer seats in the 2nd row of seats)XPull lever : in the direction of the arrow to
the pressure point and hold it in this
position.XSlide the seat forwards or backwards to the
desired position.XRelease lever :.
The seat engages audibly.
Adjusting the backrest angle
Outer seats, 2nd row
3rd row of seats
XPull lever : in the direction of the arrow to
the pressure point and hold it in this
position.XPress your back lightly against the backrest
to tilt it towards the rear.
or
XRelieve the pressure on the backrest to
allow it to fold forwards.XRelease lever : once the backrest is in the
desired position.XLean back firmly against the backrest to
ensure that it is engaged.
Adjusting the armrest (2nd row of
seats)
6-seat vehicles
You can fold the armrests in the 2nd row of
seats up, e.g. when loading the vehicle, and
adjust their height.
XTo fold up: fold the armrest up until it
engages in the vertical position.XTo adjust the height: gently push the
engaged armrest backwards to release it.XFirst fold the armrest all the way down to
its lowest position and then back up to the
desired position until it engages.
i If you want to lower the armrest, you must
first fold it up. Then adjust the height as
described above.
7-seat vehicles
The backrest of the center seat in the 2nd row
can be used as an armrest.
GWARNING
The folded second-row middle seat is
intended to serve as an armrest only. Do not
fold the second-row middle seat and allow
occupants to use the folded second-row
middle seat as a footrest while driving. All
vehicle occupants must keep both feet on the
floor in front of their seat. Otherwise,
occupants could slide under the seat belt in a
collision. If occupants slide under it, the belt
102SeatsSeats, steering wheel and mirrors