engine MERCEDES-BENZ B-CLASS 2012 Owner's Manual

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
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).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
ProCarManuals.com

Problem Possible causes/consequences and
M SolutionsThe engine cannot be
started using the
SmartKey. The on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 285).
or
X Jump-start the vehicle (Y page 289).
or
X Consult a qualified specialist workshop. The engine cannot be
started using the
SmartKey. The steering lock is mechanically blocked.
X
Remove the SmartKey and reinsert it into the ignition lock. While
doing this, turn the steering wheel in both directions. Doors
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. Unlocking and opening doors from
the inside
X
To unlock a front door: pull door
handle ;.
Locking knob : pops up.
The door is unlocked and can be opened. Doors
73
Opening and closing Z
ProCarManuals.com

You could therefore lock yourself out if:
R
the vehicle is being pushed.
R the vehicle is being towed.
R the vehicle is on a roller dynamometer.
You can also switch the automatic locking
function on and off using the on-board
computer (Y page 198). Unlocking the driver's door
(mechanical key)
If the vehicle
can no longer be unlocked with
the SmartKey, use the mechanical key.
If you use the mechanical key to unlock and
open the driver's door, the anti-theft alarm
system will be triggered ( Y page 65).
X Take the mechanical key out of the
SmartKey (Y page 69).
X Insert the mechanical key into the lock of
the driver's door as far as it will go. X
Turn the mechanical key counter-clockwise
to position 1.
The door is unlocked.
X Turn the mechanical key back and remove
it.
X Insert the mechanical key into the
SmartKey. Locking the vehicle (mechanical key)
If the vehicle

can no longer be locked with the
SmartKey, use the mechanical key. X
Open the driver's door.
X Close the front-passenger door, the rear
doors and the tailgate.
X Press the locking button (Y page 74).
X Check whether the locking knobs on the
front-passenger door and the rear doors
are still visible. Press down the locking
knobs manually, if necessary (Y page 73).
X Close the driver's door.
X Take the mechanical key out of the
SmartKey (

Y page 69).
X Insert the mechanical key into the lock of
the driver's door as far as it will go. X
Turn the mechanical key clockwise as far
as it will go to position 1.
X Turn the mechanical key back and remove
it.
X Make sure that the doors and the tailgate
are locked.
X Insert the mechanical key into the
SmartKey.
i If you lock

the vehicle as described above,
the fuel filler flap is not locked. The anti-
theft alarm system is not armed. Cargo compartment
Important safety notes
G
WARNING
Combustion engines emit poisonous exhaust
gases such as

carbon monoxide. If the tailgate
is open when the engine is running, Cargo compartment
75
Opening and closing
ZProCarManuals.com

particularly if the vehicle is moving, exhaust
fumes could enter the passenger
compartment. There is a risk of poisoning.
Turn off the engine before opening the
tailgate. Never drive with the tailgate open.
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.
! The tailgate swings upwards and to the
rear when opened. Therefore, make sure
that there is
sufficient clearance above and
behind the tailgate.
i The opening dimensions of the tailgate
can be found in the "Vehicle data" section
(Y page 335).
You should preferably place luggage or loads
in the cargo compartment. Observe the
loading guidelines ( Y page 236).
Do not leave the SmartKey in the cargo
compartment. You could otherwise lock
yourself out.
The tailgate can be:
R opened and closed manually from outside
R unlocked from inside with the mechanical
key Opening/closing from outside
Opening X
Press the % button on the SmartKey. X
Pull handle :.
X Raise the tailgate.
Closing X
Pull the tailgate down using handle :.
X Allow the tailgate to drop into the lock.
X If necessary, lock the vehicle with the
& button on the SmartKey. Tailgate emergency release
If the tailgate can no longer be opened from
outside the vehicle, use the emergency
release on the inside of the tailgate.
! The tailgate swings upwards and to the
rear when opened. Therefore, make sure
that there is

sufficient clearance above and
behind the tailgate.
i The opening dimensions of the tailgate
can be found in the "Vehicle data" section
(Y page 335). 76
Cargo compartment
Opening and closing
ProCarManuals.com

:
Front left
; Front right
= Rear right
? Rear left
i When the override feature for the side
windows is activated (
Y page 58), the side
windows
cannot be operated from the rear.
X Turn the SmartKey to position 1 or 2
in the
ignition lock.
X To open: press the corresponding switch.
X To open fully: press the corresponding
switch beyond the point of resistance.
Automatic closing is started.
X To close: pull the corresponding switch.
X To close fully: pull the corresponding
switch beyond the pressure point.
Automatic closing is started.
X To interrupt the automatic opening/
closing: press/pull the corresponding
switch again.
i If you press the switch beyond the point
of resistance, an automatic opening/
closing process is started in the
corresponding direction. You can stop
automatic operation by operating the
switch again.
i You can continue to operate the side
windows after you

switch off the engine or
remove the SmartKey. This function is
available for up to five minutes or until the
driver's or front-passenger door is opened. Convenience opening
You can ventilate

the vehicle before you start
driving. To do this, the SmartKey is used to
carry out the following functions
simultaneously:
R unlock the vehicle
R open the side windows
R open the panorama roof with power tilt/
sliding panel and the roller sunblinds
i The convenience opening feature can
only be operated using the SmartKey. The
SmartKey must be close to the driver's
door handle.
X Point the tip of the SmartKey at the driver's
door handle.
X Press and hold the % button until the
side windows and the panorama roof with
power tilt/sliding panel are in the desired
position.
If the roller

sunblinds of the panorama roof
with power tilt/sliding panel are closed, the
roller sunblinds are opened first.
X Press and hold the % button again
until
the panorama roof with power tilt/sliding
panel is in the desired position.
X To interrupt convenience opening:
release the % button. Convenience closing feature
G
WARNING
When the convenience closing feature is
operating, parts of the body could become
trapped in the

closing area of the side window
and the sliding sunroof. There is a risk of
injury.
Observe the complete closing procedure
when the convenience closing feature is
operating. Make sure that no body parts are
in close proximity during the closing
procedure. 78
Side windows
Opening and closing
ProCarManuals.com

Operating the sliding sunroof
Overhead control panel
:
To raise
; To open
= To close/lower
X Turn the SmartKey to position 1 or
2 in the
ignition lock.
X Make sure that the roller sunblinds are
open.
X Press or pull the 3 switch in the
corresponding direction.
i If you press the 3 switch beyond the
point of resistance,

an automatic opening/
closing process is started in the
corresponding direction. You can stop
automatic operation by operating the
switch again.
The automatic raising feature is available
only when the sliding sunroof is closed.
i You can continue to operate the sliding
sunroof after switching off the engine or
removing the SmartKey from the ignition
lock. This function remains active for five
minutes or until you open a front door. Operating the roller sunblinds for the
sliding sunroof
Important safety notes G
WARNING
When opening or closing the roller sunblind,
parts of the body could be trapped between the roller sunblind and the frame or sliding
sunroof. There is a risk of injury.
When opening or closing make sure that no
parts of
the

body are in the sweep of the roller
sunblind.
If somebody becomes trapped:
R release the switch immediately, or
R during automatic operation, push the
switch briefly in any direction
The opening or closing procedure will be
stopped.
The roller sunblinds shield the vehicle interior
from sunlight. The two roller sunblinds can
only be opened and closed together when the
sliding sunroof is closed.
Roller sunblind reversing feature The roller sunblinds are equipped with an
automatic reversing feature. If a solid object
blocks or
restricts

a roller sunblind during the
closing process, the roller sunblind opens
again automatically. However, the automatic
reversing feature is only an aid and does not
relieve you of the responsibility of paying
attention when closing the roller sunblinds. G
WARNING
The reversing feature does not react:
R to soft, light and thin objects, e.g. small
fingers
R when closing the roller sunblind again
manually immediately after automatic
reversing
This means that the reversing feature cannot
prevent someone being trapped in these
situations. There is a risk of injury.
When closing make sure that no parts of the
body are in the sweep of the roller sunblind.
If somebody becomes trapped:
R release the switch immediately, or
R during automatic operation, push the
switch briefly in any direction
The closing process is stopped. Panorama roof with power tilt/sliding panel
81
Opening and closing Z
ProCarManuals.com

Seats
Important safety notes
G
WARNING
Children could become trapped if they adjust
the seats, particularly when unattended.
There is a risk of injury.
When leaving the vehicle, always take the
SmartKey with you
and lock the vehicle. Never
leave children unsupervised in the vehicle. G
WARNING
You could lose control of your vehicle if you
do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint,
steering wheel and mirror and fasten your
seat belt before starting the engine. G
WARNING
If you adjust the seat height carelessly, you or
other vehicle occupants

could be trapped and
thereby injured. Children in particular could
accidentally press the electrical seat
adjustment buttons and become trapped.
There is a risk of injury.
While moving the seats, make sure that your
hands or other body parts do not get under
the lever assembly of the seat adjustment
system. G
WARNING
When you adjust a seat, you or other vehicle
occupants could become

trapped, e.g. on the
seat guide rail. There is a risk of injury.
Make sure when adjusting a seat that no one
has any body parts in the sweep of the seat. G
WARNING
The seat belt does not offer the intended level
of protection if the backrest is not in the
upright position. When

braking or in the event of an accident, you could slide underneath the
seat belt and sustain abdomen or neck
injuries, for
example.

This poses an increased
risk of injury or even fatal injury.
Adjust the seat properly before beginning
your journey. Always make sure that the seat
is in the upright position. G
WARNING
If head restraints are not installed and
adjusted correctly, they cannot provide
protection as intended.

There is an increased
risk of injury in the head and neck area, e.g.
in the event of an accident or when braking.
Always drive with the head restraints
installed. Before driving off, make sure for
every vehicle occupant that the center of the
head restraint supports the back of the head
at about eye level. 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.
! 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 Seats
87
Seats, steering wheel and mirrors Z
ProCarManuals.com

i
You can store the seat settings using the
memory function ( Y page 95).Adjusting the head restraints
G
WARNING
You could lose control of your vehicle if you
do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint,
steering wheel and mirror and fasten your
seat belt before starting the engine. G
WARNING
If head restraints are not installed and
adjusted correctly, they cannot provide
protection as intended.
There is an increased
risk of injury in the head and neck area, e.g.
in the event of an accident or when braking.
Always drive with the head restraints
installed. Before driving off, make sure for
every vehicle occupant that the center of the
head restraint supports the back of the head
at about eye level.
Adjusting the head restraints manually Adjusting the head restraint height X
To raise: pull the head restraint up to the
desired position.
X To lower: press release catch : in the
direction of the arrow and push the head
restraint down to the desired position.
Adjusting the fore/aft position of the
head restraint With this function you can adjust the distance
between the head restraint and the back of
the seat occupant's head.
X
To adjust forwards: pull the
head restraint
forwards in the direction of the arrow until
it engages.
There are several notches.
X To move backwards: press and hold
release button : and push the head
restraint backwards.
X When the head restraint is in the desired
position, release the

button and make sure
that the head restraint is engaged in
position.
Adjusting the height of the head
restraints electrically X
To adjust the head restraint height: slide
the switch for head restraint adjustment
( Y

page 88) up or down in the direction of
the arrow. Seats
89
Seats, steering wheel and mirrors Z
ProCarManuals.com

Switching the seat heating on/off
Activating/deactivating G
WARNING
Repeatedly switching on the seat heating can
cause the seat cushion and backrest pads to
become very hot. The health of persons with
limited temperature sensitivity or a limited
ability to react to excessively high
temperatures may be affected or they may
even suffer burn-like injuries. There is a risk
of injury.
Therefore, do not switch the seat heating on
repeatedly. The three red indicator lamps in the button
indicate the heating level you have selected.
The system automatically switches down
from level 3 to level 2 after approximately
eight minutes.
The system automatically switches down
from level
2
to level 1 after approximately ten
minutes.
The system automatically switches off
approximately 20 minutes after it is set to
level 1.
X Make sure that the SmartKey is in position
1 or 2 in the ignition lock.
X To switch on: press button : repeatedly
until the desired heating level is set.
X To switch off: press button : repeatedly
until all the indicator lamps go out.
i If the battery voltage is too low, the seat
heating may switch off. Problems with the seat heating The seat heating has switched off
prematurely or cannot be switched on. The
vehicle's electrical system voltage is too low
because too many electrical consumers are
switched on.
X
Switch off electrical consumers that you do
not need, such as the rear window
defroster or interior lighting. Steering wheel
Important safety notes
G
WARNING
You could lose control of your vehicle if you
do the following while driving:
R adjust the driver's seat, head restraint,
steering wheel or mirrors
R fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint,
steering wheel and mirror and fasten your
seat belt before starting the engine. G
WARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
When leaving the vehicle, always take the
SmartKey with you

and lock the vehicle. Never
leave children unsupervised in the vehicle. Adjusting the steering wheel
G
WARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose
control of the vehicle. There is a risk of an
accident.
Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion. Steering wheel
91
Seats, steering wheel and mirrors Z
ProCarManuals.com