light MERCEDES-BENZ B-CLASS 2012 Owners Manual

At speeds above 20 mph (30 km/h) the
indicator lamp
goes
out and Blind Spot Assist
is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
20 mph (30 km/h), warning lamp : on the
corresponding side lights up red. This warning
is always emitted when a vehicle enters the
blind spot monitoring range from behind or
from the side. When you overtake a vehicle,
the warning only occurs if the difference in
speed is less than 7 mph (12 km/h).
The yellow indicator lamp goes out if reverse
gear is engaged. In this event, Blind Spot
Assist is no longer active.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp : flashes. If
the turn signal remains on, vehicles detected
are indicated by the flashing of red warning
lamp :. There are no further warning tones.
Switching on Blind Spot Assist
X Make sure that the radar sensor system
(Y page 199) and Blind Spot Assist
(Y page 195)
are

activated in the on-board
computer.
X Turn the SmartKey to position 2 in the
ignition lock.
Warning lamps : in the exterior mirrors
light up red for approximately
1.5 seconds and then turn yellow.
Lane Keeping Assist General notes
Lane Keeping Assist monitors the area in
front of
your

vehicle by means of a camera at
the top of the windshield. Lane Keeping Assist
detects lane markings on the road and warns you before you leave your lane
unintentionally.
:
Lane Keeping Assist camera
If you select km on the on-board computer in
the Display Unit Speed-/Odometer:
function ( Y page 196), Lane Keeping Assist
is active starting

at a speed of 60 km/h. If the
miles display unit is selected, the assistance
range begins at 40 mph.
Important safety notes G
WARNING
Lane Keeping Assist may not always clearly
recognize lane markings.
In this case, Lane Keeping Assist may:
R give an unnecessary warning
R not give a warning
There is a risk of an accident.
Always pay particular attention to the traffic
situation and stay in lane, in particular if
warned by Lane Keeping Assist. G
WARNING
The Lane Keeping Assist warning does not
return the vehicle to the original lane. There
is a risk of an accident.
You should always steer, brake or accelerate
yourself, in particular if warned by Lane
Keeping Assist.
If you fail to adapt your driving style, Lane
Keeping Assist can

neither reduce the risk of
an accident nor override the laws of physics.
Lane Keeping Assist cannot take into account
the road, traffic and weather conditions. Lane Driving systems
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Driving and parking Z
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Keeping Assist is merely an aid. You are
responsible for the distance to the vehicle in
front, for vehicle speed, for braking in good
time and for staying in your lane.
The Lane Keeping Assist does not keep the
vehicle in the lane.
The system may be impaired or may not
function if:
R
there is poor visibility, e.g. due to
insufficient illumination of
the road, or due
to snow, rain, fog or spray
R there is glare, e.g. from oncoming traffic,
the sun or reflections (e.g. when the road
surface is wet)
R the windshield is dirty, fogged up, damaged
or covered, for instance by a sticker, in the
vicinity of the camera
R there are no, several or unclear lane
markings for a lane, e.g. in areas with road
construction work
R the lane markings are worn away, dark or
covered up, e.g. by dirt or snow
R the distance to the vehicle in front is too
small and the lane markings thus cannot be
detected
R the lane markings change quickly, e.g.
lanes branch off, cross one another or
merge
R the road is narrow and winding
R there are strong shadows cast on the lane
A warning may be given if a front wheel
passes over a lane marking. It will warn you
by means of intermittent vibration in the
steering wheel for up to 1.5 seconds.
Switching on Lane Keeping Assist X
Switch on Active Lane Keeping Assist using
the on-board computer; to do so, select
Standard or Adaptive (Y page 195).
Symbol : appears in the multifunction
display.
If you drive at speeds above 40 mph
(60 km/h
) and lane markings are detected,
symbol : is highlighted. Lane Keeping
Assist is ready for use.
When Standard is selected, no warning
vibration occurs if:
R you switch on

the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, such as
ABS, BAS or ESP ®
.
When Adaptive is selected, no warning
vibration occurs if:
R you switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time.
R a driving safety system intervenes, e.g.
ABS, BAS or ESP ®
.
R you accelerate hard, e.g. kickdown.
R you brake hard.
R you steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly.
R you cut the corner on a sharp bend.
In order that you are warned only when
necessary and in good time if you cross the
lane marking, the system recognizes certain
conditions and warns you accordingly.
The warning vibration occurs earlier if:
R you approach the outer lane marking on a
bend.
R the road has very wide lanes, e.g. a
freeway.
R the system recognizes solid lane markings.
The warning vibration occurs later if:
R the road has narrow lanes.
R you cut the corner on a bend.184
Driving systems
Driving and parking
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).Important safety notes
G
WARNING
If you operate information systems and
communication equipment integrated in the
vehicle while driving, you will be distracted
from traffic conditions. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate the equipment when the traffic
situation permits. If

you are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the
equipment when the vehicle is stationary. G
WARNING
If the instrument cluster has failed or
malfunctioned, you may not recognize
function restrictions in systems relevant to
safety. The operating safety of your vehicle
may be impaired. There is a risk of an
accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop
immediately.
You must observe the legal requirements for
the country in

which you are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the multifunction display. You should therefore
make sure your vehicle is operating safely at
all times. Otherwise, a vehicle that is not
operating safely may cause an accident.
For an overview, see the instrument panel
illustration (
Y page 29). Displays and operation
Instrument cluster lighting
The lighting in the instrument cluster, in the
displays and the controls in the vehicle
interior can be

adjusted using the brightness
control knob.
The brightness control knob is located on the
bottom left of the instrument cluster
(Y page 29).
X Turn the brightness control knob clockwise
or counter-clockwise.
If the light switch is set to Ã, T or
L, the brightness is dependent upon
the brightness of the ambient light.
i The light sensor

in the instrument cluster
automatically controls the brightness of
the multifunction display.
In daylight, the displays in the instrument
cluster are not illuminated. Coolant temperature display
G
WARNING
Driving when your engine is overheated can
cause some fluids

which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away from the engine
if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until
the engine has cooled down. 186
Displays and operation
On-board computer and displays
ProCarManuals.com

!
A display message
is shown if the coolant
temperature is too high.
If the coolant temperature is over
248 ‡(120 †), do not continue driving. The
engine will otherwise be damaged.
The coolant temperature gage is in the
instrument cluster on the right-hand side.
Under normal operating conditions and with
the specified coolant level, the coolant
temperature may rise to 248 ‡ (120 †). Tachometer
! Do not drive in the overrevving range, as
this could damage the engine.
The red band

in the tachometer indicates the
engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached. Outside temperature display
You should pay special attention to road
conditions when temperatures are around
freezing point.
The outside temperature display is in the
multifunction display.
Changes in the outside temperature are
displayed after a short delay. Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
R Cruise control activated ( Y page 157):
The segments light up from the stored
speed to the maximum speed.
R DISTRONIC PLUS activated (Y page 159):
One or two segments in the set speed
range light up.
R DISTRONIC PLUS detects

a vehicle in front:The segments between the speed of the
vehicle in front and the stored speed light
up. Operating the on-board computer
Overview :
Multifunction display
; Switches on the Voice Control System;
see the separate operating instructions
= Right control panel
? Left control panel
A Back button
X To activate the on-board computer: turn
the SmartKey to position 1 in the ignition
lock.
You

can control the multifunction display and
the settings in the on-board computer using
the buttons on the multifunction steering
wheel. Displays and operation
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On-board computer and displays Z
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A
Drive program (Y page 141)
B Transmission position ( Y page 141)
X To show menu bar ?: press the =
or ; button on the steering wheel.
Menu bar ? disappears after a few seconds.
Text field = shows the selected menu or
submenu as well as display messages.
i You can set the time using the audio
system or COMAND; see the separate
operating instructions.
The following messages may appear in the
multifunction display:
XjY Active Parking Assist (Y page 172)
CRUISE Cruise Control (Y page 157)
è Rear window wiper ( Y page 112)
_ Adaptive Highbeam Assist
(Y page 102)
À ATTENTION ASSIST (Y page 180)
à Lane Keeping Assist (Y page 183)
ë HOLD function ( Y page 167)
Ä Distance warning function
(Y page 233) Menus and submenus
Menu overview
Operating the on-board computer
(Y page 187).
Depending on the equipment installed in the
vehicle, you can call up the following menus:
R Trip menu (Y page 189)
R Navi menu (navigation instructions)
(Y page 191)
R Audio menu (Y page 192)
R Tel (telephone) menu ( Y page 193)
R DriveAssist (Assistance) menu
(Y page 194)
R Serv menu (Y page 196)
R Sett menu (Y page 196) The
Audio, Navi and
Tel
menus differ slightly
in vehicles with Audio 20 and in vehicles with
COMAND. The examples given in this
Operator's Manual apply to vehicles
equipped with COMAND. Trip menu
Standard display X
Press and hold the % button on the
steering wheel until the Trip menu with
trip odometer : and odometer ; is
shown.
Trip computer "From Start" or "From
Reset" Example: trip computer "From Start"
:
Distance
; Time
= Average speed
? Average fuel consumption
X Press the = or ; button on the
steering wheel to select the Trip menu.
X Press the 9 or : button to select
From Start or From Reset.
The values in the From Start submenu are
calculated from the start of a journey, while
the values in the From Reset submenu are
calculated from the last time the submenu
was reset ( Y page 190). Menus and submenus
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On-board computer and displays Z
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X
Start the engine.
X Press the = or ; button on the
steering wheel to select the DriveAssist
menu.
X Press the 9 or : button to select
ESP.
X Press the a button.
X To deactivate: press a again.
The å warning lamp in the instrument
cluster lights up.
X To activate: press a again.
The å warning lamp in the instrument
cluster goes out.
Switching the distance warning
function on and off X
Press the = or ; button on the
steering wheel to select the DriveAssist
menu.
X Press 9 or : to select Distance
Warning.
X Press the a button.
The current selection is displayed.
X To activate/deactivate: press the a
button again.
When the distance warning function is
activated, the multifunction display shows
the Ä symbol if the HOLD function is not
activated (Y page 167).
Vehicles with Active Parking Assist: if
PARKTRONIC is activated
and you are driving
at a speed under 22 mph (35 km/h), the j
Active Parking Assist symbol is shown instead
of the Ä symbol ( Y page 172).
Further information on the distance warning
function ( Y page 60). Activating/deactivating ATTENTION
ASSIST X
Press the = or ; button on the
steering wheel to select the DriveAssist
menu.
X Press 9 or : to select Attention
Asst.
X Press the a button.
The current selection is displayed.
X To activate/deactivate: press the a
button again.
When ATTENTION ASSIST (Y page 180) is
activated, the À symbol appears in the
multifunction display when

the ignition is on.
Activating/deactivating Blind Spot
Assist X
Press the = or ; button on the
steering wheel to select the DriveAssist
menu.
X Press 9 or :
to select Blind Spot
Assist.
X Press the a button.
The current selection is displayed.
X To activate/deactivate: press the a
button again.
For further information about Blind Spot
Assist, see (Y page 181).
When the Blind Spot Assist: Sensors
Deactivated message is shown, the radar
sensors are deactivated.
X Switch on the radar sensor system
(Y page 199).
Activating/deactivating Lane Keeping
Assist X
Press the = or ; button on the
steering wheel to select the DriveAssist
menu.
X Press 9 or : on the steering wheel
to select Lane Keep. Asst. Menus and submenus
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On-board computer and displays Z
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X
Press the a button.
The current selection is displayed.
X Press a to confirm.
X Press the : or 9 button to set Off,
Standard or Adaptive.
X Press the a button to save the setting.
If Lane Keeping Assist is activated
(Y page 183) and
the ignition is switched on,
the à symbol appears in the multifunction
display. Maintenance menu
In the
Serv menu, you have the following
options:
R Calling up display messages in message
memory ( Y page 200)
R Restarting the tire pressure loss warning
system (Y page 305)
R Calling up the service due date
(Y page 270) Settings menu
Introduction In the
Sett menu, you have the following
options:
R changing the instrument cluster settings
R changing the light settings
R changing the vehicle settings R
changing the convenience settings
R restoring the factory settings
Instrument cluster Selecting the unit of measurement for
distance
You can
determine

whether the multifunction
display shows some messages in miles or
kilometers.
X Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Inst. Cluster submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Display Unit Speed-/Odometer:
function.
You will see the selected setting km or
miles.
X Press the a button to save the setting.
The selected unit of measurement for
distance applies to:
R the digital speedometer in the Trip menu
R the odometer and the trip odometer
R the trip computer
R the current consumption and the range
R the navigation instructions in the Navi
menu
R cruise control
R DISTRONIC PLUS
R ASSYST PLUS service interval display
Switching the additional speedometer
on/off
Only vehicles
with

manual transmission have
this function.
X Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Inst. Cluster submenu.
X Press a to confirm.196
Menus and submenus
On-board computer and displays
ProCarManuals.com

X
Press : or 9 to select the
Speedometer [mph]: function.
You will see the selected setting: On or
Off.
X Press the a button to save the setting.
i Speed is displayed in mph.
The Speedometer [mph] function
allows you
to choose whether the status area in the
multifunction display always shows the speed
in mph instead of the outside temperature.
Selecting the permanent display function
You can determine whether the multifunction
display permanently shows your speed or the
outside temperature.
X Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or
9

button to select the
Inst. Cluster submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Permanent Display: function.
You will see the selected setting Outside
Temperature or Speedometer [km/h]
(USA)/ Speedometer [mph] (Canada).
X Press the a button to save the setting.
i The speed is shown in km/h (USA)/
mph
(Canada).
Lights Switching the daytime running lamps on/
off
Daytime running lamps are required by law
(Canada only). You cannot set the "daytime
running lamps" function via the on-board
computer.
X
Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Lights submenu.
X Press a to confirm. X
Press the : or 9
button to select the
Daytime Running Lights function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
Further information on daytime running
lamps ( Y page 99).
Switching Adaptive Highbeam Assist on/
off
X Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Lights submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Adaptive Highbeam Assist function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
For further information about Adaptive
Highbeam Assist, see ( Y page 102).
Setting the brightness of the ambient
lighting
X Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Lights submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Amb. Light +/-function.
You will see the selected setting.
X Press a to confirm.
X Press the :
or 9

button to adjust the
brightness to any level from Off to Level
5 (bright).
X Press the a or % button to
save the
setting. Menus and submenus
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On-board computer and displays Z
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Activating/deactivating surround
lighting and exterior lighting delayed
switch-off
If you have activated the
Locator
Lighting: function
and
the light switch is set
to Ã, the following functions are activated
when it is dark:
R surround lighting: the exterior lighting
remains lit for 40 seconds after unlocking
with the SmartKey. If you start the engine,
the surround lighting is switched off and
automatic headlamp mode is activated
(Y page 99).
R exterior lighting delayed switch-off: the
exterior lighting remains lit for
60 seconds after the engine is switched off.
If you close all the doors and the trunk lid,
the exterior lighting goes off after
15 seconds.
X Press the = or ; button on the
steering wheel to select the Sett. menu.
X Press the :
or 9
button to select the
Lights submenu.
X Press a to confirm.
X Press the : or 9
button to select the
Locator Lighting function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
Deactivating delayed switch-off of the
exterior lighting temporarily:
X Before leaving the vehicle, turn the
SmartKey to position 0

in the ignition lock.
X Turn the SmartKey to position 2 in the
ignition lock.
The exterior lighting delayed switch-off is
deactivated.
Delayed switch-off of the exterior lighting is
reactivated the next time you start the
engine.
i Depending on your vehicle's equipment,
when the surround lighting and delayed
switch-off exterior lighting are on, the
following light up: R
Parking lamps
R Front fog lamps
R Low-beam headlamps
R Daytime running lamps
R Side marker lamps
R Surround lighting in the exterior mirrors
Activating/deactivating the interior
lighting delayed switch-off
If you activate the Interior Lighting
Delay function, the interior lighting remains
on for 20seconds after you remove the
SmartKey from the ignition lock.
X Press the = or ; button on the
steering wheel to select the Sett. menu.
X Press the : or 9
button to select the
Lights submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Interior Lighting Delay function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
Vehicle Activating/deactivating the automatic
door locking mechanism
X
Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the :
or 9
button to select the
Vehicle submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Automatic Door Lock function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
If you select the Automatic Door Lock
function, the
vehicle

is centrally locked above
a speed of around 9 mph (15 km/h).
i For further information on the automatic
locking feature, see ( Y page 74).198
Menus and submenus
On-board computer and displays
ProCarManuals.com

Activating/deactivating the acoustic
locking verification signal
If you switch on the Acoustic Lock
Feedback: function, an acoustic signal
sounds when you lock the vehicle.
X
Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9 button to select the
Vehicle submenu.
X Press a to confirm.
X Press the :
or 9

button to select the
Acoustic Lock Feedback: function.
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
Activating/deactivating the radar sensor
system
X Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Vehicle submenu.
X Press a to confirm.
X Press the 9 or : button to select
Radar Sensor (See Oper. Manual).
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
Convenience Switching the fold-in mirrors when
locking feature on/off
This function
is

only available on vehicles with
the memory function ( Y page 95).
X Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Convenience submenu.
X Press a to confirm. X
Press the : or 9
button to select the
Fold Mirrors in when Locking:
You will see the selected setting: Enabled
or Disabled.
X Press the a button to save the setting.
If you switch on the Fold Mirrors in
when
Locking: function, the exterior mirrors fold
in when you lock the vehicle. If you unlock the
vehicle and then open the driver's or front-
passenger door, the exterior mirrors fold out
again.
If you have switched the function on and you
fold the exterior mirrors in using the button
on the door (Y page 93), they will not fold out
automatically. The exterior mirrors can then
only be folded out using the button on the
door.
Restoring the factory settings X
Press the = or ; button on the
steering wheel to select the Sett menu.
X Press the : or 9
button to select the
Factory Setting submenu.
X Press a to confirm.
The Reset All Settings? message
appears.
X Press the : or 9 button to select
No or Yes.
X Press a to confirm the selection.
If you have

selected Yes , the multifunction
display shows a confirmation message.
For safety reasons, the Daytime Running
Lights: function in the Lights submenu is
only reset if the vehicle is stationary. Menus and submenus
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