warning light MERCEDES-BENZ B-CLASS 2012 Owner's Manual

G
WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
BAS operates in emergency braking
situations. If you depress the brake pedal
quickly, BAS automatically
boosts the braking
force, thus shortening the stopping distance.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. COLLISION PREVENTION ASSIST
General notes COLLISION PREVENTION ASSIST consists of
the Adaptive Brake Assist and the distance
warning function, which are described in the
following.
Distance warning function
Important safety notes
i
Observe the "Important safety notes"
section for driving safety systems
(Y page 59). G
WARNING
The distance warning function does not react:
R to people or animals
R to oncoming vehicles
R to crossing traffic
R when cornering
Thus, the distance warning function cannot
provide a warning in all critical situations.
There is a risk of an accident.
Always pay careful attention to the traffic
situation and be ready to brake.
The distance warning

function cannot always
clearly identify objects and complex traffic
situations. In such cases, the distance warning function
may:
R
give an unnecessary warning
R not give a warning
Always pay careful attention to the traffic
situation and do not rely solely on the
distance warning function.
Function
X To activate/deactivate: activate or
deactivate the distance

warning function in
the on-board computer (Y page 195).
If the distance warning function is activated,
the Ä symbol appears

in the multifunction
display unless the HOLD function is active
(Y page 168).
On vehicles with Active Parking Assist, the
Ä symbol is displayed when P is engaged
or you are driving faster than 22 mph
(35 km/h).
The distance warning function can help you
to minimize the risk of a front-end collision
with a vehicle ahead or reduce the effects of
such a collision. If the distance warning
function detects that there is a risk of a
collision, you will be warned visually and
acoustically. The distance warning function
cannot prevent a collision without your
intervention.
Starting at a speed of around 20 mph
(30 km/h), this function warns you if you
rapidly approach a vehicle in front. An
intermittent warning tone will then sound and
the · distance warning lamp will light up
in the instrument cluster.
X Brake immediately in order to increase the
distance from the vehicle in front.
or
X Take evasive action provided it is safe to do
so.
For the distance warning function to assist
you when driving, the function must be
activated in the on-board computer and be
operational ( Y page 195).60
Driving safety systems
Safety
ProCarManuals.com

Up to vehicle speeds of around 155 mph
(250 km/h
),
adaptive Brake Assist is capable
of reacting to moving objects that have
already been recognized as such at least once
over the period of observation. Adaptive
Brake Assist does not react to stationary
obstacles.
If Adaptive Brake Assist is not available due
to a malfunction in the radar sensor system,
the brake system remains available with full
brake boosting effect and BAS.
In particular, the detection of obstacles can
be impaired if there is:
R dirt on the sensors or anything else
covering the sensors
R snow or heavy rain
R interference by other radar sources
R there are strong radar reflections, for
example in parking garages
R a narrow vehicle traveling in front, e.g. a
motorbike
R a vehicle traveling in front on a different line
relative to the center of your vehicle
Following damage to the front end of the
vehicle, have the configuration and operation
of the radar sensor checked at a qualified
specialist workshop. This also applies to
collisions at low speeds where there is no
visible damage to the front of the vehicle. Adaptive brake lights
If you brake sharply from a speed of more
than 50 km/h

or if braking is assisted by BAS
or Adaptive Brake Assist, the brake lamps
flash rapidly. In this way, traffic traveling
behind you is warned in an even more
noticeable manner.
If you brake sharply to a standstill from a
speed of more than 70 km/h, the hazard
warning lamps are activated automatically. If
the brakes are applied again, the brake lamps
light up continuously. The hazard warning
lamps switch off automatically if you travel
faster than 10 km/h. You can also switch off the hazard warning lamps using the hazard
warning button (Y page 101).
i
Adaptive brake lamps

are only available in
certain countries. ESP
®
(Electronic Stability Program)
General notes i
Observe the "Important safety notes"
section ( Y page 59).
ESP ®
monitors driving stability and traction,
i.e. power transmission

between the tires and
the road surface.
If ESP ®
detects that the vehicle is deviating
from the direction desired by the driver, one
or more wheels are braked to stabilize the
vehicle. The engine output is also modified to
keep the vehicle on the desired course within
physical limits. ESP ®
assists the driver when
pulling away on wet or slippery roads. ESP ®
can also stabilize the vehicle during braking.
ETS (Electronic Traction System) i
Observe the "Important safety notes"
section for driving safety systems
(Y page 59).
ETS traction control is part of ESP ®
.
ETS brakes the drive wheels individually if
they spin. This enables you to pull away and
accelerate on slippery surfaces, for example
if the road surface is slippery on one side.
ETS remains active when you deactivate
ESP ®
.
Important safety notes G
WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further
driving safety systems are deactivated. This
increases the risk

of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop. 62
Driving safety systems
Safety
ProCarManuals.com

!
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
63
Safety Z
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SmartKey battery
Important safety notes G
WARNING
Batteries contain toxic and corrosive
substances. If batteries
are swallowed, it can
result in severe health problems. There is a
risk of fatal injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National
guidelines must be observed during disposal.
In California, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/
index.cfm.
Mercedes-Benz recommends that you have
the batteries replaced at a qualified specialist
workshop.
Checking the battery X
Press the & or % button.
The battery is working properly if battery
check lamp : lights up briefly.
The battery is discharged if battery check
lamp : does not light up briefly.
X Change the battery ( Y page 70). i
If the SmartKey battery is checked within
the signal reception range of the vehicle,
pressing the &

or % button:
R locks or
R unlocks the vehicle
i You can get a battery at any qualified
specialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery.
X
Take the mechanical key out of the
SmartKey (Y page 69). X
Press mechanical key ; into the opening
in the SmartKey in the direction of the
arrow until battery tray cover : opens.
When doing so,

do not hold cover : shut.
X Remove battery tray cover :. X
Repeatedly tap the SmartKey against your
palm until battery = falls out.
X Insert the new battery with the positive
terminal facing upwards. Use a lint-free
cloth to do so.70
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
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Opening and closing Z
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You can reach the emergency release via the
cargo compartment. Fold the rear backrests
forward (
Y page 240).
X Take the mechanical key out of the
SmartKey (Y page 69). X
Insert mechanical key ; into the opening
in paneling :.
X Turn mechanical key ; 90° clockwise.
X Push mechanical key ; in the
direction of
the arrow and open the tailgate. Side windows
Important safety notes
G
WARNING
While opening the side windows, body parts
in the closing area could become trapped.
There is a risk of injury.
Make sure that no body parts are in close
proximity during the closing procedure. If
somebody becomes trapped, release the
switch or press the switch to open the side
window again. G
WARNING
If children operate the side windows they
could become trapped,

particularly if they are
left unsupervised. There is a risk of injury.
Activate the override feature for the rear side
windows. When leaving the vehicle, always
take the SmartKey with you and lock the
vehicle. Never leave children unsupervised in
the vehicle. Side window reversing feature
The side windows are equipped with an
automatic reversing feature. If a solid object
blocks or restricts a side window during the
closing process, the

side window 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 a side window. G
WARNING
The reversing feature does not react:
R to soft, light and thin objects, e.g. small
fingers
R over the last

4 mm of the closing movement
R during resetting
R when closing the side window 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.
Make sure that no body parts are in close
proximity during the closing procedure. If
someone becomes trapped, press the switch
to open the side window again. Opening and closing the side
windows
The switches for

all side windows are located
on the driver's door. There is also a switch on
each door for the corresponding side window.
The switches on the driver's door take
precedence. Side windows
77
Opening and closing Z
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When you lock the vehicle, you can
simultaneously:
R
close the side windows
R close the panorama roof with power tilt/
sliding panel
On vehicles with
a panorama roof with power
tilt/sliding panel, you can then close the
roller sunblinds.
i 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 fully closed.
X Make sure that all the side windows and the
panorama roof with power tilt/sliding
panel are closed.
On vehicles with a panorama roof with power
tilt/sliding panel:
X Press and hold the & button again
until
the roller sunblinds of the panorama roof
with power tilt/sliding panel close.
X To interrupt convenience closing:
release the & button.Resetting the side windows
You must reset each side window if:
R the side window opens again slightly after
being closed fully.
R the side window can no longer be fully
opened or closed.
X Close all the doors.
X Turn the SmartKey to position 1
or 2
in the
ignition lock.
X Pull the corresponding switch on the door
control panel until the side window is
completely closed ( Y page 77).
X Hold the switch for an additional second. If the side window opens again slightly:
X
Immediately
pull the corresponding switch
on the door control panel until the side
window is completely closed ( Y page 77).
X Hold the switch for an additional second.
X If the corresponding side window remains
closed after the button has been released,
the side window has been reset correctly.
If this is not the case, repeat the steps
above again. Problems with the side windows
G
WARNING
If you close a side window again immediately
after it has been blocked or reset, the side
window closes with increased or maximum
force. The reversing

feature is then not active.
Parts of the body could be trapped in the
closing area in the process. This poses an
increased risk of injury or even fatal injury.
Make sure that no parts of the body are in the
closing area. To stop the closing process,
release the switch or push the switch again to
reopen the side window.
Problem: a side window cannot be closed
because it is blocked by objects, e.g.
leaves in the window guide.
X Remove the objects.
X Close the side window.
Problem: a side window cannot be closed
and you cannot see the cause. If a side
window is obstructed during closing and
reopens again slightly:
X Immediately after the window blocks, pull
the corresponding switch again until the
side window has closed.
The side window is closed with increased
force. Side windows
79
Opening and closing Z
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If a side window is obstructed again during
closing and reopens again slightly:
X
Immediately after the window blocks, pull
the corresponding switch again until the
side window has closed.
The side window
is closed without the anti-
entrapment feature. Panorama roof with power tilt/sliding
panel
Important safety notes
In the following section, the term "sliding
sunroof" refers to the panorama roof with
power tilt/sliding panel. G
WARNING
While opening and closing the sliding sunroof,
body parts in close proximity could become
trapped. There is a risk of injury.
Make sure that no body parts are in close
proximity during the opening and closing
procedures.
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. G
WARNING
If children operate the sliding sunroof they
could become trapped,

particularly if they are
left unsupervised. 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.
! Only open the sliding sunroof if it is free
of snow and ice. Otherwise, malfunctions
may occur.
Do not allow anything to protrude from the
sliding sunroof. Otherwise, the seals could
be damaged. !
The weather can

change abruptly. It could
start to rain or snow. Make sure that the
sliding sunroof is closed when you leave the
vehicle. The vehicle electronics can be
damaged if water enters the vehicle
interior.
i Resonance noises can occur in addition
to the usual airflow noises when the sliding
sunroof is open. They are caused by minor
pressure fluctuations in the vehicle interior.
Change the position of the sliding sunroof
or open a side window slightly to reduce or
eliminate these noises. Sliding sunroof reversing feature
The sliding sunroof is equipped with an
automatic reversing feature. If a solid object
blocks or restricts the sliding sunroof during
the closing process,

the sliding sunroof 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 sliding sunroof. G
WARNING
The reversing feature does not react:
R to soft, light and thin objects, e.g. small
fingers
R over the last

4 mm of the closing movement
R during resetting
R when closing the sliding sunroof 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.
Make sure that no body parts are in close
proximity during the closing procedure.
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. 80
Panorama roof with power tilt/sliding panel
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

Opening and closing
Overhead control panel
:
To open
; To open
= To close
X Turn the SmartKey to position 1 or
2 in the
ignition lock.
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.
Resetting the sliding sunroof and the
roller sunblinds If the sliding sunroof or the roller sunblinds
do not move smoothly, reset the sliding
sunroof and the roller sunblinds:
X
Turn the SmartKey to position 1 or 2
in the
ignition lock.
X Press the 3 switch to the point of
resistance in the

direction of arrow ; and
hold it until the sliding sunroof has opened
about 4 in (10 cm).
X Pull the 3 switch
repeatedly
to the point
of resistance in the direction of arrow =
until the sliding sunroof is fully closed.
X Keep the 3 switch pulled for an
additional second. X
Press the 3 switch to the point of
resistance in the

direction of arrow ; and
hold it until the roller sunblinds are open
about 4 in (10 cm).
X Pull the 3 switch
repeatedly
to the point
of resistance in the direction of arrow =
until the roller sunblinds are fully closed.
X Keep the 3 switch pulled for an
additional second.
X Make sure that the sliding sunroof
(Y page 81) and the roller sunblinds
(Y page
82)

can be fully opened and closed
again.
X If this is not the case, repeat the steps
above again. Problems with the sliding sunroof
G
WARNING
If you do not reset the sliding sunroof after a
malfunction or voltage supply interruption,
then the backing

up function will malfunction
or not work. The sliding sunroof closes with
increased or maximum force. Parts of the
body could be trapped in the closing area in
the process. This poses an increased risk of
injury or even fatal injury.
In such or similar situations always make sure
that no parts of the body are in the closing
area. Always reset the sliding sunroof after a
malfunction or voltage supply interruption.
! If the sliding sunroof still cannot be
opened or closed as a result of a
malfunction, contact a qualified specialist
workshop.
Problem: the sunroof cannot be closed
and you cannot see the cause. If the sliding
sunroof is obstructed during closing and
reopens again slightly:
X Immediately after it blocks, pull the 3
switch down again to the point of 82
Panorama roof with power tilt/sliding panel
Opening and closing
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