2012 MERCEDES-BENZ B-CLASS ignition

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
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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
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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
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R
ADAPTIVE BRAKE ( Y
page 64)
(Y page 64)
R STEER CONTROL ( Y page 64)Important safety notes
If you fail to adapt your driving style or
become distracted, the driving safety
systems can neither reduce the risk of
accident nor override the laws of physics.
Driving safety systems are merely aids
designed to assist driving. You are
responsible for the distance to the vehicle in
front, for vehicle speed and for braking in
good time. Always

adapt your driving style to
suit the prevailing road, weather and traffic
conditions and maintain a safe distance from
the vehicle in front. Drive carefully.
i The driving safety systems described only
work as effectively as possible when there
is adequate contact between the tires and
the road surface. Pay particular attention
to the information regarding tires,
recommended minimum tire tread depths
etc. in the "Wheels and tires" section
(Y page 298).
In wintry driving conditions, always use
winter tires (M+S tires) and if necessary,
snow chains. Only in this way will the
driving safety systems described in this
section work as effectively as possible. ABS (Anti-lock Braking System)
Important safety notes i
Observe the "Important safety notes"
section for driving safety systems
(Y page 59). G
WARNING
If ABS is faulty, the wheels could lock when
braking. The steerability and braking
characteristics may be severely impaired.
Additionally, further driving safety systems are deactivated. There is an increased danger
of skidding and accidents.
Drive on carefully. Have ABS checked
immediately at a qualified specialist
workshop.
When ABS is malfunctioning, other systems,
including driving safety systems, will also
become inoperative. Observe

the information
on the ABS warning lamp ( Y page 225) and
display messages which may be shown in the
instrument cluster (Y page 201).
ABS regulates brake pressure in such a way
that the wheels do not lock when you brake.
This allows you to continue steering the
vehicle when braking.
ABS works from a speed of about 5 mph
(8 km/h) upwards, regardless of road-surface
conditions. ABS works on slippery roads,
even if you only brake gently.
The ! ABS warning lamp in the instrument
cluster lights up when the ignition is switched
on. It goes out when the engine is running.
Braking X
If ABS intervenes: continue to
depress the
brake pedal vigorously until the braking
situation is over.
X To make a full brake application:
depress the brake pedal with full force.
If ABS intervenes when braking, you will feel
a pulsing in the brake pedal.
The pulsating brake pedal can be an
indication of hazardous road conditions, and
functions as a reminder to take extra care
while driving. BAS (Brake Assist System)
i Observe the "Important safety notes"
section ( Y page 59). Driving safety systems
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!
When testing the electric parking brake
on a braking dynamometer, switch off the
ignition. Application of the brakes by
ESP ®
may otherwise destroy the brake
system.
When towing your vehicle with the front axle
raised, observe the notes on
ESP ®
(Y page 293).
ESP ®
is deactivated if the å ESP®
OFF
warning lamp in
the instrument cluster lights
up continuously when the engine is running.
If the ÷ ESP ®
warning lamp and the
å ESP ®
OFF warning lamp are lit
continuously, ESP ®
is not available due to a
malfunction.
Observe the information on warning lamps
(Y page 227) and display messages which
may be shown in the instrument cluster
(Y page 201).
i Only use wheels with the recommended
tire sizes. Only then will ESP ®
function
properly.
Characteristics of ESP ®General information
ESP
®
is activated automatically when the
engine is started.
If ESP ®
intervenes, the ÷ ESP®
warning
lamp flashes in the instrument cluster.
If ESP ®
intervenes:
X Do not deactivate ESP ®
under any
circumstances.
X Only depress the accelerator pedal as far
as necessary when pulling away.
X Adapt your driving style to suit the
prevailing road and weather conditions.
Vehicles with the ECO start/stop function Deactivating/activating ESP
® Important safety notes
i
Observe the "Important safety notes"
section for driving safety systems
(Y page 59).
You can select between the following states
of ESP ®
:
R ESP ®
is activated.
R ESP ®
is deactivated. G
WARNING
If you deactivate ESP ®
, ESP ®
no longer
stabilizes the vehicle. There is an increased
risk of skidding and an accident.
Only deactivate ESP ®
in the situations
described in the following.
It may be best to deactivate ESP ®
in the
following situations:
R when using snow chains
R in deep snow
R on sand or gravel
i Activate ESP ®
as soon as the situations
described above no

longer apply. ESP®
will
otherwise not be able to stabilize the
vehicle if the vehicle starts to skid or a
wheel starts to spin.
! Avoid spinning the driven wheels for an
extended period with ESP ®
deactivated.
You could otherwise damage the drivetrain.
Deactivating/activating ESP ®
You can deactivate or activate ESP ®
via the
on-board computer.
X To deactivate: (Y page 194).
The å ESP ®
OFF warning lamp in the
instrument cluster lights up.
X To activate: (Y page 194).
The å ESP ®
OFF warning lamp in the
instrument cluster goes out. Driving safety systems
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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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ATA (anti-theft alarm system)
X
To arm: lock the vehicle with the
SmartKey.
Indicator lamp : flashes. The alarm
system is armed after approximately
15 seconds.
X To disarm: unlock the vehicle with the
SmartKey.
or
X Insert the SmartKey into the ignition lock.
A visual and audible alarm is triggered if the
alarm system is armed and you open:
R the vehicle with the mechanical key
R a door
R the tailgate
R the hood
X To stop the alarm: insert the SmartKey
into the ignition lock.
The alarm is switched off.
or
X Press the % or & button on the
SmartKey.
The alarm is switched off.
The alarm is not switched off, even if you
close the open door that triggered it, for
example. i
If the alarm stays on for more than
30 seconds, the Tele
Aid system initiates a
call to the Customer Assistance Center
automatically. The Tele Aid system will
initiate the call provided that:
R you have subscribed to the Tele Aid
service.
R the Tele Aid service has been activated
properly.
R the necessary mobile phone, power
supply and GPS coverage are available. Theft deterrent locking system
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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).SmartKey
Important safety notes
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shift the automatic transmission out of
parking position P.
R starting the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you

and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
WARNING
If persons, particularly children are subjected
to prolonged exposure to extreme heat or
cold, there is a risk of injury, possibly even
fatal. Never leave children unattended in the
vehicle. G
WARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be
unintentionally turned in

the ignition lock. This
could cause the engine to be switched off.
There is a risk of an accident.
Do not attach any heavy or large objects to
the SmartKey. Remove any bulky key rings
before inserting the SmartKey into the
ignition lock.
! Keep the SmartKey away from strong
magnetic fields. Otherwise, the remote
control function could be affected.
Strong magnetic fields can occur in the
vicinity of powerful electrical installations.
Do not keep the SmartKey:
R with electronic devices, e.g. a mobile
phone or another SmartKey
R with metallic objects, e.g. coins or metal
foil
R inside metallic objects, e.g. a metal case SmartKey functions
:
& To lock the vehicle
; % To unlock the vehicle
X To unlock centrally: press button ;.
If you do not open the vehicle within
approximately 40 seconds of unlocking:
R the vehicle is locked again.
R the theft

deterrent locking system is armed
again. 68
SmartKey
Opening and closing
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