2012 MERCEDES-BENZ B-CLASS service

vehicle occupant or from outside the
vehicle.
R the electrical system in the engine
compartment, the battery
or the fuses have
been tampered with.
R the battery is disconnected.
R the accelerator pedal has been depressed,
e.g. by a vehicle occupant.
There is a risk of an accident.
If you wish to exit the vehicle, always turn off
DISTRONIC PLUS and secure the vehicle
against rolling away.
Deactivating DISTRONIC PLUS
(Y page 165).
If DISTRONIC PLUS detects that the vehicle
in front is stopping, it brakes your vehicle until
it is stationary.
Once your vehicle is stationary, it remains
stationary and you do not need to depress the
brake.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake.
i Depending on the specified minimum
distance, your vehicle will come to a
standstill at a sufficient distance behind the
vehicle in front. The specified minimum
distance is set using the control on the
cruise control lever.
The electric parking brake automatically
secures the vehicle if DISTRONIC PLUS is
activated and:
R the driver's door is open and the driver's
seat belt is unfastened.
R the engine is switched off, unless it is
automatically switched off by the ECO
start/stop function.
R a system malfunction occurs.
R the power supply is not sufficient.
If a malfunction occurs, then the transmission
may be shifted into position P automatically.Storing the current speed or calling up the
last stored speed G
WARNING
If you call up the stored speed and it differs
from the current speed, the vehicle
accelerates or decelerates.

If you do not know
the stored speed, the vehicle could accelerate
or brake unexpectedly. There is a risk of an
accident.
Pay attention to the road and traffic
conditions before calling up the stored speed.
If you do not know the stored speed, store the
desired speed again.
X Briefly pull the cruise control lever
(Y page 161) towards you.
X Remove your foot from the accelerator
pedal.
DISTRONIC PLUS is activated. The first
time it is activated, the current speed is
stored. Otherwise, it

sets the vehicle cruise
speed to the previously stored value.
Setting a speed Keep in mind that it may take a brief moment
until the
vehicle

has accelerated or braked to
the speed set. :
To store the current speed or a higher
speed
; To store the current speed or a lower
speed164
Driving systems
Driving and parking
ProCarManuals.com

!
If DISTRONIC PLUS
or the HOLD function
is activated, the vehicle brakes
automatically in certain situations. To
prevent damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or other similar situations:
R when towing the vehicle
R in the car wash
Deactivate the HOLD function (Y page 168).
General notes The HOLD function can assist the driver in the
following situations:
R
when pulling away, especially on steep
slopes
R when maneuvering on steep slopes
R when waiting in traffic
The vehicle is kept stationary without the
driver having to depress the brake pedal.
The braking effect

is canceled and the HOLD
function deactivated when you depress the
accelerator pedal to pull away.
Activation conditions You can activate the HOLD function if:
R
the vehicle is stationary
R the engine is running or if it has been
automatically switched off by the ECO
start/stop function
R the driver's
door

is closed or your seat belt
is fastened
R the electric parking brake is released
R the transmission position D, R or N is
engaged while driving a vehicle with an
automatic transmission
R DISTRONIC PLUS is deactivated Activating the HOLD function X
Make sure that the activation conditions
are met.
X Depress the brake pedal.
X Quickly depress the brake pedal further
until : appears in the multifunction
display.
The HOLD function is activated. You can
release the brake pedal.
i If depressing the brake pedal the first
time does not activate the HOLD function,
wait briefly and then try again.
Deactivating the HOLD function The HOLD function is deactivated
automatically if:
R
you accelerate. On

vehicles with automatic
transmission: only when the transmission
is in position D or R.
R the transmission is in position P on vehicles
with automatic transmission.
R you depress the brake pedal again with a
certain amount of pressure until :
disappears from the multifunction display.
R you secure the vehicle using the electric
parking brake.
R you activate DISTRONIC PLUS.
i After a time, the electric parking brake
secures the vehicle and relieves the service
brake. 168
Driving systems
Driving and parking
ProCarManuals.com

If you press and hold
9 or :, the
rapid scrolling speed is increased. Not all
audio drives or data carriers support this
function.
If track information is stored on the audio
device or medium, the multifunction display
will show the number and title of the track.
The current track does not appear in audio
AUX mode (Auxiliary audio mode: external
audio source connected).
Video DVD operation DVD changer display (example)
:
Current DVD in the DVD changer
; Current scene
X Switch on COMAND and select video DVD;
see the separate operating instructions.
X Press the = or ; button on the
steering wheel to select the Audio menu.
X To select the next/previous scene:
briefly press the 9 or : button.
X To select a scene from the scene list
(rapid scrolling): press and hold the
9 or : button until desired
scene ; has been reached. Telephone menu
Introduction 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.
When telephoning, you must observe the
legal requirements for the country in which
you are currently driving.
X Switch on your mobile phone and audio
system or COMAND, see the separate
operating instructions.
X Establish a Bluetooth ®
connection to the
audio system or COMAND; see the
separate operating instructions.
X Press the = or ; button on the
steering wheel to select the Tel menu.
You will see one of the following display
messages in the multifunction display:
R Phone READY or the name of the network
provider: the mobile phone has found a
network and is ready to receive.
R Phone No Service: there is no network
available or the mobile phone is searching
for a network.
Accepting a call Example: incoming call
X
Press the 6 button on the steering
wheel to accept an incoming call.
If someone calls you when you are in the
Tel menu, a display message appears in the
multifunction display.
If you are not in the Tel menu, you can still
accept a call. Menus and submenus
193
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

Display messages Possible causes/consequences and
M Solutions$(USA
only)J(Canada
only)
Check Brake Fluid
Level There is not enough brake fluid in the brake fluid reservoir.
In addition, the $ (USA only)/J (Canada only) warning
lamp lights up in the instrument cluster and a warning tone
sounds.
G WARNING
The braking effect may be impaired.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road
and traffic conditions. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away ( Y page 149).
X Consult a qualified specialist workshop.
X Do not add brake fluid. This does not correct the malfunction. #
Check Brake Pad
Wear The brake pads/linings have reached their wear limit.
X
Visit a qualified specialist workshop. G
mbrace Inoperative One or more main features of the mbrace system are
malfunctioning.
X
Have the mbrace system checked immediately at a qualified
specialist workshop. 6
SRS Malfunction
Service Required There is a malfunction in the SRS (Supplemental Restraint
System). The 6 warning lamp also lights up in the instrument
cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop.
Further information on occupant safety (Y page 38). Display messages
207
On-board computer and displays Z
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Display messages Possible causes/consequences and
M Solutions6
Front Left
Malfunction
Service Required 
or Front Right
Malfunction
Service Required SRS has malfunctioned at the front on the left or right. The
6
warning lamp also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Rear Left
Malfunction
Service Required 
or Rear Right
Malfunction
Service Required SRS has malfunctioned at the rear on the left or right. The
6
warning lamp also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Rear Center
Malfunction
Service Required SRS has malfunctioned at the rear center. The
6 warning lamp
also lights up in the instrument cluster.
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. 6
Left Side Curtain
Airbag
Malfunction
Service Required  
or 
Right Side
Curtain Airbag
Malfunction
Service Required There is a malfunction in the left-hand or right-hand window
curtain air bag. The
6 warning lamp also lights up in the
instrument cluster.
G WARNING
The left or right window curtain air bag may either be triggered
unintentionally or, in the event of an accident, may not be
triggered.
There is an increased risk of injury.
X Visit a qualified specialist workshop. Lights
i Display messages about LEDs:208
Display messages
On-board computer and displays
ProCarManuals.com

Display messages Possible causes/consequences and
M SolutionsService Required
Do Not Shift Gears
Visit Dealer You cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position
D is selected:
X Drive to a qualified specialist workshop without shifting the
transmission from position D.
If transmission position R, N or P is selected:
X Notify a qualified specialist workshop or breakdown service. Only Shift
to 'P' when
Vehicle is
Stationary The vehicle is moving.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Shift the transmission to position P.Reversing Not
Possible Service
Required The automatic transmission is malfunctioning. You cannot back
up.
X
Visit a qualified specialist workshop. Transmission
Malfunction The automatic transmission is malfunctioning.
X
Visit a qualified specialist workshop. Transmission
Malfunction Stop The automatic transmission is malfunctioning.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 149).
X Consult a qualified specialist workshop. Stop Vehicle Shift
to P Leave Engine
Running The automatic transmission has overheated.
X
Drive on carefully.
The automatic transmission
is available again when the display
message goes out.
If the display message continues to be displayed:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 149).
X Wait until the automatic transmission has cooled down and the
display message has disappeared. Display messages
221
On-board computer and displays Z
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Display messages Possible causes/consequences and
M SolutionsA The tailgate is open.
G WARNING
When the engine is running, exhaust gases can enter the vehicle
interior if the tailgate is open.
There is a risk of poisoning.
X Close the tailgate. ? The hood is open.
G WARNING
The open hood may block your view when the vehicle is in motion.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Apply the electric parking brake.
X Close the hood. C At least one door is open. A warning tone also sounds.
X
Close all the doors. Ð
Power Steering
Malfunction See
Operator's Manual The power steering is malfunctioning.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident.
X Check whether you are able to apply the extra force required.
X If you are able to steer safely:
carefully drive
on to a qualified
specialist workshop.
X If you are unable to steer safely: do not
drive on. Contact the
nearest qualified specialist workshop. Phone No Service Your vehicle is outside the network provider's transmitter/
receiver range.
X
Wait until the mobile phone operational readiness symbol
appears in the multifunction display.222
Display messages
On-board computer and displays
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