2012 MERCEDES-BENZ B-CLASS key

Wear indicator (definition)
.............318
Wheel rim (definition) ....................316
see Flat tire

Top Tether ............................................ 55
Towing Important safety guidelines ...........291
Installing the towing eye ................ 292
Removing the towing eye ...............292
Towing away
With both axles on the ground ....... 293
With front axle raised ..................... 293
Tow-starting
Emergency engine starting ............ 294
Important safety notes .................. 291
Installing the towing eye ................ 292
Removing the towing eye ...............292
Traction control ................................... 62
Transmission see Automatic transmission
Transmission position display .........141
Transporting the vehicle .................. 293
Trim pieces (cleaning instructions) . 276
Trip computer (on-board computer) 189
Trip odometer Calling up ....................................... 189
Resetting (on-board computer) ...... 190
Trunk
see Tailgate
Turn signals
Changing bulbs (front) ................... 108
Changing bulbs (rear) .................... 109
Display message ............................ 209
Switching on/off ........................... 100
Type identification plate
see Vehicle identification plate U
Unlocking Emergency unlocking .......................75
From inside the vehicle (central
unlocking button) ............................. 74 V
Vanity mirror (in the sun visor) ........ 249
Vehicle Correct use ...................................... 24
Data acquisition ............................... 25
Equipment
....................................... 21
Individual settings ..........................196
Limited Warranty ............................. 25
Loading .......................................... 306
Locking (in an emergency) ............... 75
Locking (SmartKey) .......................... 68
Lowering ........................................ 322
Maintenance .................................... 22
Parking for a long period ................ 152
Pulling away ................................... 136
Raising ........................................... 320
Reporting problems .........................24
Securing from rolling away ............320
Towing away .................................. 291
Tow-starting ................................... 291
Transporting .................................. 293
Unlocking (in an emergency) ........... 75
Unlocking (SmartKey) ......................68
Vehicle data ................................... 335
Vehicle data ....................................... 335
Vehicle dimensions ...........................335
Vehicle emergency locking ................75
Vehicle identification number see VIN
Vehicle identification plate ..............328
Vehicle tool kit .................................. 280
Video (DVD) ........................................ 193
VIN ...................................................... 328 W
Warning and indicator lamps ABS ................................................ 225
Brakes

........................................... 225
Check Engine ................................. 231
Coolant .......................................... 231
Distance warning ........................... 233
DISTRONIC PLUS ........................... 233
ESP ®
.............................................. 227
ESP ®
OFF ....................................... 228
Fuel tank ........................................ 231
Overview .......................................... 3018
Index
ProCarManuals.com

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note
that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: ( Y page 24).Panic alarm
X
To activate: press ! button : for at
least one second.
An alarm sounds and the exterior lighting
flashes.
X To deactivate: press ! button :
again.
or
X Insert the SmartKey into the ignition lock. Occupant safety
Important safety notes
G
WARNING
Modifications to or work improperly
conducted on restraint system components
or their wiring, as well as tampering with interconnected electronic systems, can lead
to the
restraint
systems no longer functioning
as intended.
Air bags or Emergency Tensioning Devices
(ETDs), for example, could deploy
inadvertently or fail to deploy in accidents
although the deceleration threshold for air
bag deployment is exceeded. Therefore,
never modify the restraint systems. Do not
tamper with electronic components or their
software.
In this section, you will learn the most
important facts about the restraint system
components of the vehicle.
The restraint system consists of:
R Seat belts
R Child restraint systems
R LATCH-type (ISOFIX) child seat securing
system
Additional protection is provided by:
R SRS (Supplemental Restraint System)
R Air bag system components with the
PASSENGER AIRBAG OFF indicator lamp
The different air bag systems work
independently of each other. The protective
functions of the system work in conjunction
with each other. Not all air bags are always
deployed in an accident.
i For information on infants and children
traveling with you in the vehicle restraint
systems for infants and children, see
"Children in the vehicle" ( Y page 50). SRS (Supplemental Restraint System)
Introduction Supplemental Restraint System (SRS) with:
R
The 6 SRS warning lamp
R Air bags
R Air bag control unit (with crash sensors)38
Occupant safety
Safety
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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 fitted
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. Always
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. G
WARNING
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 G
WARNING
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. Occupant safety
47
Safety Z
ProCarManuals.com

passenger front air bag is deactivated.
Should the 4 5 indicator lamp not
illuminate or go out while the restraint is
installed, please check installation.
Periodically check
the 4
5 indicator
lamp while driving to make sure the 4
5 indicator lamp is illuminated. If the
4 5 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 have to 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, and secure child restraint with
the vehicle's seat belt according to the
child seat manufacturer's instructions. G
WARNING
Infants and small children should never share
a seat belt

with another occupant. In the event
of 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 that are too large for a child restraint
must travel in seats using normal seat belts.
Position the shoulder belt across the chest
and shoulder, not the face or neck. A booster
seat may be necessary to achieve proper seat
belt positioning for children over 41 lbs
(18 kg) until they reach a height where a lap/
shoulder belt fits properly without a booster
seat.
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.
G
WARNING
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. G
WARNING
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 Children in the vehicle
51
Safety Z
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Warning notice on the front-passenger sun visor
Warning symbol for a rearward-facing child
restraint system
Do not use a rearward-facing child restraint
system on a seat that is protected by an air
bag installed in front of it.
Air bag deactivation system on the
front-passenger seat
G
WARNING
If the 4 PASSENGER AIRBAG OFF
indicator lamp does not light up when the
child restraint system is installed, the front-
passenger air bag has not been disabled. If
the front-passenger air
bag deploys, the child
could be seriously or even fatally injured.
Proceed as follows:
R do not use a rearward-facing child restraint
system on the front-passenger seat.
R install a rearward-facing child restraint
system on a suitable rear seat.
or R
only use a forward-facing child restraint
system on the front-passenger seat and
move the front-passenger seat to the
rearmost position.
R have the air bag deactivation system
checked at a

qualified specialist workshop.
To ensure that the air bag deactivation system
on the front-passenger seat functions/
communicates correctly, never place objects,
e.g. a cushion, under the child restraint
system. The entire base of the child restraint
system must always rest on the seat cushion.
An incorrectly installed child restraint system
cannot perform its intended protective
function in the event of an accident, and could
lead to injuries. G
WARNING
Do not place electronic devices on the front-
passenger seat, e.g.:
R laptops, when switched on
R mobile phones
R cards with transponders,

e.g. ski passes or
access cards
Signals from electronic equipment can cause
interference in the sensor system of the air
bag deactivation system. This can lead to a
system malfunction. This may cause the
4 PASSENGER AIR BAG OFF indicator
lamp to light up even if no child seat with a
transponder for an air bag deactivation
system is installed. The front-passenger air
bag would not then deploy during an accident.
It is also possible that the 6 SRS warning
lamp lights up and/or the 4 PASSENGER
AIR BAG OFF indicator lamp does not light up
briefly when you turn the key in the ignition
lock to position 2. Children in the vehicle
53
Safety Z
ProCarManuals.com

If the front-passenger seat of your vehicle
does not
have
an air bag deactivation system,
this is indicated by a special sticker. The
sticker is affixed to the side of the dashboard
on the front-passenger side. The sticker is
visible when you open the front-passenger
door.
Vehicles without an air bag deactivation
system on the front-passenger seat: if you
turn the SmartKey to position 2 in the ignition
lock, the 45 indicator lamp lights up
briefly but has no function. It does not
indicate that there is an air bag deactivation
system on the front-passenger seat. The sensor system for the air bag deactivation
system detects
whether

a special Mercedes-
Benz child seat with a transponder for the air
bag deactivation system has been installed.
In this case, 45 indicator lamp :
lights up. The front-passenger front air bag is
deactivated: i
If the front-passenger front air bag is
disabled by the air bag deactivation
system, the following remain enabled on
the front-passenger side:
R the side impact air bag
R the window curtain air bag
R the Emergency Tensioning Device
LATCH-type (ISOFIX) child

seat anchors
in the rear G
WARNING
Children that are too large for a child restraint
must travel in seats using normal seat belts.
Position the shoulder belt across the chest
and shoulder, not the face or neck.
A booster seat may be necessary to achieve
proper seat belt positioning for children over
41 lbs (18 kg

) until they reach a height where
a normal shoulder/lap belt fit properly
without a booster.
Install the child seat according to
manufacturer's instructions.
The child seat must be firmly attached to both
anchors.
An incorrectly installed child restraint system
could come loose during an accident and
seriously or even fatally injure the child.
Damaged or impact damaged child seats or
child seat mountings must be replaced.
! When installing the LATCH-type (ISOFIX)
child restraint system, make sure that the
seat belt for the center seat does not get
trapped. Otherwise, the seat belt could be
damaged. 54
Children in the vehicle
Safety
ProCarManuals.com

Problems with the air bag deactivation system
Problem Possible causes/consequences and
M SolutionsThe 45
indicator lamp on the
center console is lit. A special Mercedes-Benz child restraint system with a
transponder for
air
bag deactivation system has been installed to
the front-passenger seat. The front-passenger front air bag has
therefore been disabled as desired. G
WARNING
There is no child restraint system installed on the front-passenger
seat. The air bag deactivation system is malfunctioning.
It is also

possible that the 6 SRS warning lamp lights up and/
or the 45 indicator lamp does not light up briefly when you
switch the ignition on.
There is a risk of injury.
X Remove electronic equipment from the front-passenger seat,
for example:
R
Laptop
R Mobile phone
R Cards with transponders,

such as ski passes or access cards
If the 45 indicator lamp remains lit:
X Visit a qualified specialist workshop. Child-proof locks
Important safety notes G
WARNING
Activate the child-proof locks for the rear
doors and the override switch for the rear
windows when children are travelling in the
vehicle. Otherwise, the children could open
doors or side windows while the vehicle is in
motion and injure themselves or others. G
WARNING
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, Children in the vehicle
57
Safety
ZProCarManuals.com

Characteristics when ESP
®
is deactivated
If ESP ®
is deactivated and one or more wheels
start to spin, the ÷ ESP®
warning lamp in
the instrument cluster flashes. In such
situations, ESP ®
will not stabilize the vehicle.
If you deactivate ESP ®
:
R ESP ®
no longer improves driving stability.
R the engine's torque is no longer limited and
the drive wheels are able to spin. The
spinning of the wheels results in a cutting
action, which provides better grip.
R ETS is still active.
R ESP ®
still provides support when you
brake. EBD (electronic brake force
distribution)
i Observe the "Important safety notes"
section for driving safety systems
(Y page 59). G
WARNING
If EBD has malfunctioned, the rear wheels can
still lock, e.g. under full braking. This
increases the risk

of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified
specialist workshop.
Observe information regarding indicator and
warning lamps ( Y page 225) as well as
display messages ( Y page 203).
EBD monitors and controls the brake
pressure on the rear wheels to improve
driving stability while braking. ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety
and offers increased braking comfort. In
addition to the braking function, ADAPTIVE
BRAKE also has the HOLD function
(Y page 168) and hill start assist (Y page 136). For further information, see
Driving tips (Y page 154).
STEER CONTROL
STEER CONTROL helps

you by transmitting a
noticeable steering force to the steering
wheel in the direction required for vehicle
stabilization.
This steering assistance is provided in
particular if:
R both right wheels or both left wheels are on
a wet or slippery road surface when you
brake
R the vehicle starts to skid
If ESP ®
is malfunctioning, you will not receive
steering support from STEER CONTROL.
Power steering will, however, continue to
function. Theft deterrent locking system
Immobilizer
The immobilizer prevents your vehicle from
being started without the correct SmartKey.
X To activate: remove the SmartKey from
the ignition lock.
X To deactivate: switch on the ignition.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. The
engine can be started by anyone with a valid
SmartKey that is left inside the vehicle.
i The immobilizer is always deactivated
when you start the engine.
In the event that the engine cannot be
started when the starter battery is fully
charged, the immobilizer may be faulty.
Contact an authorized Mercedes-Benz
Center or call

1-800-FOR-MERCedes (in the
USA) or 1-800-387-0100 (in Canada). 64
Theft deterrent locking system
Safety
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