2012 MERCEDES-BENZ B-CLASS ECU

Switching the surround lighting
on/off (on-board computer)
..........198
Turn signals ................................... 100
see Changing bulbs

see Interior lighting
Light sensor (display message) .......211
Loading guidelines ............................236
Locking see Central locking
Locking (doors)
Automatic ........................................ 74
Emergency locking ........................... 75
From inside (central locking
button) ............................................. 74
Locking centrally
see Central locking
Locking verification signal (on-
board computer) ............................... 199
Low-beam headlamps Changing bulbs .............................. 107
Display message ............................ 209
Setting for driving abroad
(symmetrical) ................................... 98
Switching on/off .............................. 99
Lumbar support
Adjusting the 4-way lumbar
support ............................................ 90M
M+S tires ............................................ 300
Maintenance see ASSYST PLUS


Malfunction message
see Display messages
Matte finish (cleaning instructions) 273
mbrace Call priority .................................... 255
Display message ............................ 207
Downloading destinations
(COMAND) ..................................... 256
Downloading routes .......................259
Emergency call .............................. 253
Geo fencing ................................... 259
Important safety notes .................. 251
Locating a stolen vehicle ............... 258
MB info call button ........................ 255
Remote vehicle locking .................. 257Roadside Assistance button ..........
254
Search & Send ............................... 256
Self-test ......................................... 252
Speed alert .................................... 259
System

.......................................... 252
Triggering the vehicle alarm ........... 260
Vehicle remote malfunction
diagnosis ....................................... 258
Vehicle remote unlocking .............. 257
Mechanical key
Function/notes ................................ 69
Locking vehicle ................................ 75
Unlocking the driver's door ..............75
Memory card (audio) ......................... 192
Memory function ................................. 95
Message memory (on-board
computer) .......................................... 200
Messages see Display messages
Mirrors
see Exterior mirrors
see Rear-view mirror
see Vanity mirror (in the sun visor)
Mobile phone
Menu (on-board computer) ............ 193
Modifying the programming
(SmartKey) ........................................... 69
MOExtended tires .............................. 281
Mounting wheels Lowering the vehicle ......................322
Mounting a new wheel ................... 322
Preparing the vehicle .....................319
Raising the vehicle ......................... 320
Removing a wheel ..........................322
Securing the vehicle against
rolling away ................................... 320
MP3
Operation ....................................... 192
see separate operating instructions
Multifunction display
Function/notes ............................. 188
Permanent display ......................... 197
Multifunction steering wheel
Operating the on-board computer . 187
Overview .......................................... 3112
Index
ProCarManuals.com

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

including interference that may cause
undesired operation of the device."
Diagnostics connection
The diagnostics connection is only intended
for the connection
of diagnostic equipment at
a qualified specialist workshop. G
WARNING
If you connect equipment to the diagnostics
connection in the vehicle, it may affect the
operation of the

vehicle systems. As a result,
the operating safety of the vehicle could be
affected. There is a risk of an accident.
Do not connect any equipment to a
diagnostics connection in the vehicle. G
WARNING
Objects in the driver's footwell can restrict the
pedal travel or obstruct a depressed pedal.
The operating and road safety of the vehicle
is jeopardized. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter
the driver's footwell. Install the floormats
securely and as specified in order to ensure
sufficient clearance for

the pedals. Do not use
loose floormats.
! If the engine is switched off and
equipment on the diagnostics connection
is used, the starter battery may discharge.
Connecting equipment to the diagnostics
connection can lead to emissions monitoring
information being reset, for example. This
may lead to the vehicle failing to meet the
requirements of the next emissions test
during the main inspection. Qualified specialist workshop
An authorized Mercedes-Benz Center is a
qualified specialist workshop. It has the
necessary specialist knowledge, tools and
qualifications to correctly carry out the work required on your vehicle. This is especially the
case for work relevant to safety.
Observe the notes in the Maintenance
Booklet.
Always have
the

following work carried out at
an authorized Mercedes-Benz Center:
R work relevant to safety
R service and maintenance work
R repair work
R alterations, installation work and
modifications
R work on electronic components Correct use
If you remove any warning stickers, you or
others could fail

to recognize certain dangers.
Leave warning stickers in position.
Observe the following information when
driving your vehicle:
R the safety notes in this manual
R the Technical Data section in this manual
R traffic rules and regulations
R laws and safety standards pertaining to
motor vehicles Problems with your vehicle
If you should

experience a problem with your
vehicle, particularly one that you believe may
affect its safe operation, we urge you to
contact an authorized Mercedes-Benz Center
immediately to have the problem diagnosed
and rectified. If the problem is not resolved to
your satisfaction, please discuss the problem
again with a Mercedes-Benz Center or
contact us at one of the following addresses.
In the USA
Customer Assistance Center
Mercedes-Benz USA, LLC
One Mercedes Drive
Montvale, NJ 07645-0350
In Canada 24
Introduction
ProCarManuals.com

Customer Relations Department
Mercedes-Benz Canada, Inc.
98 Vanderhoof Avenue
Toronto, Ontario M4G 4C9
Reporting safety defects
USA only:
The following text
is published as required of
manufacturers under Title 49, Code of U.S.
Federal Regulations, Part 575 pursuant to the
"National Traffic and Motor Vehicle Safety Act
of 1966".
If you believe that your vehicle has a defect
which could cause a crash or could cause
injury or death, you should immediately
inform the National Highway Traffic Safety
Administration (NHTSA) in addition to
notifying Mercedes-Benz USA, LLC.
If NHTSA receives similar complaints, it may
open an investigation, and if it finds that a
safety defect exists in a group of vehicles, it
may order a recall and remedy campaign.
However, NHTSA cannot become involved in
individual problems between you, your
dealer, or Mercedes-Benz USA, LLC.
To contact NHTSA, you may call the Vehicle
Safety Hotline toll-free at
1-888-327-4236(TTY: 1-800-424-9153); go
to http://www.safercar.gov ; or write to:
Administrator, NHTSA, 400 Seventh Street,
SW., Washington, DC 20590.
You can also obtain other information about
motor vehicle safety from
http://www.safercar.gov Limited Warranty
! Follow the instructions in this manual
about the proper operation of your vehicle
as well as about possible vehicle damage.
Damage to your vehicle that arises from
culpable contraventions against these
instructions is not covered either by the Mercedes-Benz Limited Warranty or by the
New or Used-Vehicle Warranty.
Data stored in the vehicle
Information about electronic data
acquisition in the vehicle
(Including notice pursuant
to California Code
§ 9951)
Your vehicle records electronic data. If your
vehicle is equipped with mbrace (Canada:
TELE AID), data is transmitted in the event of
an accident.
This information helps, for example, to test
vehicle systems after an accident and to
continually improve vehicle safety.
Daimler AG can access this data and submit
it:
R for safety research or vehicle diagnosis
purposes
R with the consent of the vehicle owner
R on the instruction of prosecuting
authorities
R for use in arbitration of disputes that
involve Daimler AG, its affiliates or its sales
and service organizations
R as otherwise required or permitted by law.
Please check your mbrace (Canada: TELE
AID) purchase agreement to find out more
about data that can be recorded and
transmitted by this system. Information on copyright
General information
Information on license for free and open-
source software used in your vehicle and its
electronic components is available on the
following website:
http://www.mercedes-benz.com/
opensource Introduction
25 Z
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
ProCarManuals.com

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
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accelerates rapidly in a longitudinal
direction during the initial stages of the
impact
R if, in the
event of a side impact, on the side
opposite the impact the vehicle
decelerates or accelerates rapidly in a
lateral direction
R if, in certain situations where the vehicle
rolls over, the system determines that it
can provide additional protection
If the ETDs are deployed, you will hear a bang,
and a small amount of powder may also be
released. Only in rare cases will the bang
affect your hearing. The powder that is
released generally does not constitute a
health hazard. The 6 SRS warning lamp
lights up.
If the seat belt is also equipped with a seat
belt force limiter and this is triggered, the
force exerted by the seat belt on the vehicle
occupant is reduced.
The seat belt force limiters for the front seats
are synchronized with the front air bags,
which take on a part of the deceleration force.
This results in the force exerted on the
occupant being distributed over a greater
area. Children in the vehicle
Child restraint systems
Important safety notes G
WARNING
According to accident statistics, children are
safer when properly restrained in the rear
seating positions than in the front seating
position. Thus, we strongly recommend that
children be placed

in the rear seats whenever
possible. Regardless of seating position,
children 12 years old and under must be
seated and properly secured in an appropriate
infant restraint, toddler restraint, or booster
seat recommended for the size and weight of
the child. The infant or child restraint must be properly
secured with the vehicle's seat belt, the seat
belt and
top

tether strap, or lower anchors and
top tether strap, fully in accordance with the
child seat manufacturer's instructions.
Occupants, especially children, should always
sit as upright as possible, wear the seat belt
properly and use an appropriately sized infant
restraint, toddler restraint, or booster seat
recommended for the size and weight of the
child.
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 For children larger than the typical
12-month-old child, the front passenger
front air bag may or may not be activated.
Always make sure the 4 5 indicator
lamp is illuminated, indicating that the front
passenger front air bag is deactivated.
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
completely eliminate this risk is to never
place a child in a rear-facing child restraint
in the front seat. We therefore strongly
recommend that you always place a child
in a rear-facing child restraint in a backseat.
R If you must install a rear-facing child
restraint on the front passenger seat
because circumstances require you to do
so, make sure the 4 5 indicator
lamp is illuminated, indicating that the front 50
Children in the vehicle
Safety
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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