2012 MERCEDES-BENZ B-CLASS warning

Have aftermarket accessories installed at
a qualified specialist workshop.
You could jeopardize the operating safety of
your vehicle if
you use parts, tires and wheels
as well as accessories relevant to safety
which have not been approved by Mercedes.
This could lead to malfunctions in safety-
relevant systems, e.g. the brake system. Use
only genuine Mercedes-Benz parts or parts of
equal quality. Only use tires, wheels and
accessories that have been specifically
approved for your vehicle.
Genuine Mercedes-Benz parts are subject to
strict quality control. Every part has been
specifically developed, manufactured or
selected for and adapted to Mercedes-Benz
vehicles. Only genuine Mercedes-Benz parts
should therefore be used.
More than 300,000 different genuine
Mercedes-Benz parts are available for
Mercedes-Benz models.
All authorized Mercedes-Benz Centers
maintain a supply of genuine Mercedes-Benz
parts for necessary service and repair work.
In addition, strategically located parts
delivery centers provide quick and reliable
parts service.
Always specify the vehicle identification
number (VIN) ( Y page 328) and the engine
number (Y page 329) when ordering genuine
Mercedes-Benz parts. Operator's Manual
General notes
Before you first

drive off, read this Operator's
Manual carefully and familiarize yourself with
your vehicle.
For your own safety and a longer vehicle life,
follow the instructions and warning notices in
this manual. Disregarding them may lead to
damage to the vehicle or personal injury.
Vehicle damage resulting from the disregard
of the instructions is not covered by the
Mercedes-Benz Limited Warranty. Vehicle equipment
This Operator's Manual describes all models
and all standard and optional equipment of
your vehicle available at the time of going to
print. 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. The

equipment in your vehicle
may therefore differ from some of the
descriptions or illustrations.
The original purchase agreement lists all
systems installed in your vehicle.
Contact an authorized Mercedes-Benz Center
if you have any questions about equipment or
operation.
The Operator's Manual and Maintenance
Booklet are important documents and should
be kept in the vehicle. Service and vehicle operation
Service and literature
Your vehicle is

covered under the terms of the
warranties printed in the Service and
Warranty Information booklet. Your
authorized Mercedes-Benz Center will
exchange or repair any defective parts
originally installed in the vehicle in
accordance with the terms of the following
warranties:
R New Vehicle Limited Warranty
R Emission Systems Warranty
R Emission Performance Warranty
R California, Connecticut, Maine,
Massachusetts, New York, Pennsylvania,
Rhode Island and Vermont Emission
Control Systems Warranty
R State warranty enforcement laws (lemon
laws) Introduction
21 Z
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Operating safety
Important safety notes
G
WARNING
If you do not have the prescribed service/
maintenance work or any required repairs
carried out, this
can result in malfunctions or
system failures. There is a risk of an accident.
Always have the prescribed service/
maintenance work as well as any required
repairs carried out at a qualified specialist
workshop. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or

not at all. This could affect,
for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk
of an accident.
Do not switch off the ignition while driving. G
WARNING
Modifications to electronic components, their
software as well as wiring can impair their
function and/or the function of other
networked components. In particular,
systems relevant to safety could also be
affected. As a result, these may no longer
function as intended and/or jeopardize the
operating safety of the vehicle. There is an
increased risk of an accident and injury.
Never tamper with the wiring as well as
electronic components or

their software. You
should have all work to electrical and
electronic equipment carried out at a qualified
specialist workshop.
There is a risk of damage to the vehicle if:
R the vehicle becomes stuck, e.g. on a high
curb or an unpaved road
R you drive too fast over an obstacle, e.g. a
curb or a hole in the road
R a heavy object strikes the undercarriage or
parts of the chassis. In situations like this, the body, the
undercarriage, chassis parts, wheels or tires
could be
damaged

without the damage being
visible. Components damaged in this way can
unexpectedly fail or, in the case of an
accident, no longer withstand the strain they
are designed to.
If the underbody paneling is damaged,
combustible materials such as leaves, grass
or twigs can gather between the underbody
and the underbody paneling. If these
materials come in contact with hot parts of
the exhaust system for an extended period,
they can catch fire.
Have the vehicle checked and repaired
immediately at a qualified specialist
workshop. If on continuing your journey you
notice that driving safety is impaired, pull over
and stop the vehicle immediately, paying
attention to road and traffic conditions. In
such cases, visit a qualified specialist
workshop. Declarations of conformity
Vehicle components which receive
and/or transmit radio waves USA: "The wireless devices of this vehicle
comply with Part 15 of the FCC Rules.
Operation is subject to the following two
conditions: 1) These devices may not cause
harmful interference, and 2) These devices
must accept any interference received,
including interference that may cause
undesired operation. Changes or
modifications not expressly approved by the
party responsible for compliance could void
the user’s authority to operate the
equipment."
Canada:
"The wireless

devices of this vehicle
comply with Industry Canada license-exempt
RSS standard(s). Operation is subject to the
following two conditions: (1) These devices
may not cause interference, and (2) These
devices must accept any interference, Introduction
23 Z
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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

Dashboard
Function Page
:
Steering wheel paddle
shifters
144
;
Combination switch 100
=
Instrument cluster 29
?
Horn
A
DIRECT SELECT lever 140
B
PARKTRONIC warning
display
169
C
Overhead control panel 34
D
Climate control systems
118 Function Page
E
Ignition lock 135
F
Adjusting the steering
wheel
91
G
Cruise control lever 158
H
Electric parking brake 150
I
Light switch 98
J
Diagnostics connection 24
K
Opening the hood 26628
DashboardAt a glance
ProCarManuals.com

Warning and indicator lamps
Function Page
:
L Low-beam
headlamps
99
;
T Parking lamps
100
=
K High-beam
headlamps
100
?
÷ ESP
® 227
A
! Electric parking brake
(red)
230
B
!
Electric parking brake
(yellow) 230
C
· Distance warning
233
D
#! Turn signals
100 Function Page
E
6 SRS
230
F
ü Seat belt
224
G
? Coolant
231
H
R Rear fog lamp
100
I
N Front fog lamps
99
J
; Check Engine
231
K
æ Reserve fuel
231
L
å ESP
®
OFF 227
M
! ABS
225
N
J Brakes
22530
Instrument clusterAt a glance
ProCarManuals.com

Center console
Center console, upper section
Function Page
:
Audio system/COMAND;
see the separate operating
instructions
;
c Seat heating
91
=
c PARKTRONIC
169
?
¤ ECO start/stop
function
136 Function Page
A
£ Hazard warning
lamps
101
B
4 PASSENGER AIRBAG
OFF indicator lamp
53
C
Ú Selects the drive
program
14332
Center consoleAt a glance
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

R
Emergency Tensioning Device
for the front
seat belts and the outer seat belts in the
rear
R Seat belt force limiters for the front seat
belts and the outer seat belts in the rear
SRS reduces the risk of occupants coming
into contact with parts of the vehicle's interior
in the event of an accident. It can also reduce
the effect of the forces to which occupants
are subjected during an accident.
SRS warning lamp G
WARNING
The SRS self-check has detected a
malfunction if the 6 SRS indicator lamp:
R does not light up at all
R does not go out after approximately four
seconds after the engine is started
R lights up
after

the engine is started or while
the vehicle is in motion
For your safety, Mercedes-Benz strongly
recommends that you have the system
checked as soon as possible at a qualified
specialist workshop. SRS may otherwise fail
to activate when it is needed in the event of
an accident, which could lead to serious or
fatal injuries. SRS might also be activated
unexpectedly and unnecessarily, which could
also result in injury.
In addition, work carried out improperly on
SRS may render SRS inoperative or cause
unintended air bag deployment. Work on the
SRS system should only be carried out by
qualified specialist personnel. Consult a
qualified specialist workshop.
If it is necessary to modify an air bag system
to accommodate a person with disabilities,
contact an authorized Mercedes-Benz Center
for details. USA only: for further information,
contact our Customer Assistance Center at
1-800-FOR-MERCedes (1-800-367-6372).
The 6 SRS warning lamp in the instrument
cluster lights up when the ignition is switched on. It goes out no later than a few seconds
after the engine is started.
SRS
functions are

checked regularly when the
ignition is switched on or the engine is
running. Therefore, malfunctions can be
detected in good time.
Triggering of Emergency Tensioning
Device and air bags During the first stage of a collision, the air bag
control unit evaluates important physical
data relating to vehicle deceleration or
acceleration, such as:
R
duration
R direction
R magnitude
Based on the evaluation of this data, the air
bag control unit pre-emptively triggers the
Emergency Tensioning Device in the first
stage.
If there is an even higher rate of vehicle
deceleration or acceleration in a longitudinal
direction, the front

air bags are also deployed.
Your vehicle has adaptive, two-stage front air
bags. The air bag control unit evaluates
vehicle deceleration or acceleration in the
event of a collision. In the first deployment
stage, the front air bag is filled with enough
propellant gas to reduce the risk of injuries.
The front air bag is fully deployed if a second
deployment threshold is reached within a few
milliseconds.
The Emergency Tensioning Device and air bag
triggering thresholds are variable and are
adapted to the detected rate of deceleration
or acceleration of the vehicle. This process is
pre-emptive in nature. The triggering process
must take place in good time at the start of
the collision.
The rate of vehicle deceleration or
acceleration and the direction of the force are
essentially determined by:
R the distribution of forces during the
collision
R the collision angle Occupant safety
39
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