MERCEDES-BENZ B-CLASS 2012 Owners Manual

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
199
On-board computer and displays Z
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Display messages
General notes
Display messages appear in the multifunction display.
Display messages with graphic displays may be shown in simplified form in the Operator's
Manual and may differ from the messages shown in the multifunction display.
Please respond in accordance with the display messages and follow the additional notes in
this Operator's Manual.
Certain display messages
are accompanied by an audible warning tone or a continuous tone.
When the ignition is switched off, all display messages are deleted, apart from some high-
priority display messages. Once the causes of the high-priority display messages have been
rectified, the corresponding display messages are also deleted.
When you stop and park the vehicle, please observe the notes on the HOLD function
(Y page 167) and parking ( Y page 149).Hiding display messages
X Press the a or % button on the steering wheel to hide the display message.
The display message is cleared.
The multifunction display shows high-priority display messages in red. Some high-priority
display messages cannot be hidden.
The multifunction display shows these messages continuously until the causes for the
messages have been remedied. Message memory
The on-board computer saves certain display messages in the message memory. You can
call up the display messages:
X Press = or ; on the steering wheel to select the Serv menu.
If there are display messages, the multifunction display shows, for example, 2 Messages.
X Press the 9 or : button to select the entry, e.g. 2 Messages.
X Press a to confirm.
X Press the 9 or : button to scroll through the display messages.200
Display messages
On-board computer and displays
ProCarManuals.com

Safety systems
Display messages Possible causes/consequences and
M Solutions!÷
Currently
Unavailable See
Operator's Manual ABS (Anti-lock Braking System), ESP
®
(Electronic Stability
Program), BAS (Brake Assist), the HOLD function and hill start
assist are temporarily unavailable.
COLLISION PREVENTION ASSIST may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster.
ATTENTION ASSIST is deactivated.
Possible causes are:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not
operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Carefully drive a short distance on a suitable stretch of road,
making slight steering movements at a speed above 12 mph
(20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop. !÷
Inoperative See
Operator's Manual ABS, ESP
®
, BAS, the HOLD function and hill start assist are
unavailable due to a malfunction.
COLLISION PREVENTION ASSIST may also have failed.
In addition, the J, ÷, å and ! warning lamps light
up in the instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example. Display messages
201On-board computer and displays Z
ProCarManuals.com

Display messages Possible causes/consequences and
M SolutionsThe steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP
®
is not
operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. ÷
Currently
Unavailable See
Operator's Manual ESP
®
, BAS, the HOLD function and hill start assist are temporarily
unavailable.
COLLISION PREVENTION ASSIST may also have failed.
In addition, the ÷

and å warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
The self-diagnosis function might not be complete, for example.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Carefully drive a short distance on a suitable stretch of road,
making slight steering movements at a speed above 12 mph
(20 km/h).
If the display message disappears, the functions mentioned
above are available again.
If the display message continues to be displayed:
X Drive on carefully.
X Visit a qualified specialist workshop.202
Display messages
On-board computer and displays
ProCarManuals.com

Display messages Possible causes/consequences and
M Solutions÷
Inoperative See
Operator's Manual ESP
®
, BAS, the HOLD function and hill start assist are unavailable
due to a malfunction.
COLLISION PREVENTION ASSIST may also have failed.
In addition, the ÷
and å warning lamps light up in the
instrument cluster.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Drive on carefully.
X Visit a qualified specialist workshop. T!
÷
Inoperative See
Operator's Manual EBD (electronic brake force distribution), ABS, ESP
®
, BAS, the
HOLD function and hill start assist are not available due to a
malfunction.
COLLISION PREVENTION ASSIST may also have failed.
In addition, the ÷, å and ! warning lamps light up in
the instrument cluster and a warning tone sounds.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not

operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. F(USA
only)!(Canada
only) The red
F (USA only)/! (Canada only) indicator lamp
flashes and a warning tone sounds. A condition for automatic
release of the electric parking brake is not fulfilled ( Y page 150).
You are driving with the electric parking brake applied.
X Release the electric parking brake manually. Display messages
203
On-board computer and displays Z
ProCarManuals.com

Display messages Possible causes/consequences and
M SolutionsPlease Release
Parking Brake
The red
F (USA only)/! (Canada only) indicator lamp
flashes and a warning tone sounds.
You are using the electric parking brake for emergency braking
(Y page 150). F(USA
only)!(Canada
only)
Parking Brake See
Operator's Manual The yellow
! warning lamp lights up.
The electric parking brake is malfunctioning.
To apply:
X Switch the ignition off.
X Press the electric parking brake handle for at least ten seconds.
X Shift the transmission to P.
X Consult a qualified specialist workshop. The yellow
! warning lamp and the red F (USA
only)/! (Canada only) indicator lamp light up.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
or
X Release the electric parking brake automatically ( Y page 150).
If the electric parking brake still cannot be released:
X Do not drive on.
X Consult a qualified specialist workshop.204
Display messagesOn-board computer and displays
ProCarManuals.com

Display messages Possible causes/consequences and
M SolutionsThe red
F (USA only)/! (Canada only) indicator lamp
flashes and the yellow ! warning lamp lights up.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
To apply:
X Switch off the ignition and turn it back on.
X Apply the electric parking brake manually.
If the red F (USA only)/! (Canada only) indicator lamp
continues to flash:
X Do not drive on.
X Secure the vehicle against rolling away ( Y page 320).
X Shift the transmission to P.
X Turn the front wheels towards the curb.
X Consult a qualified specialist workshop. The yellow
! warning lamp lights up. The red F (USA
only)/! (Canada only) indicator lamp flashes for about ten
seconds after the electric parking brake has been applied or
released. It then goes out or remains lit.
The electric parking brake is malfunctioning.
X Switch off the ignition and turn it back on.
X Apply the electric parking brake.
If it is not possible to engage the electric parking brake:
X Shift the transmission to P.
X Visit a qualified specialist workshop.
If it is not possible to release the electric parking brake:
X Release the electric parking brake automatically ( Y page 150).
If the electric parking brake still cannot be released:
X Consult a qualified specialist workshop. Display messages
205On-board computer and displays Z
ProCarManuals.com

Display messages Possible causes/consequences and
M SolutionsThe yellow
! warning lamp lights up. If you manually apply or
release the electric parking brake, the red F (USA
only)/! (Canada only) indicator lamp flashes.
The electric parking brake is malfunctioning. It is not possible to
apply the electric parking brake manually.
X Shift the transmission to P.
X Visit a qualified specialist workshop. F(USA
only)!(Canada
only)
Parking Brake
Inoperative The yellow
! warning lamp lights up. The red F (USA
only)/! (Canada only) indicator lamp flashes for about ten
seconds after the electric parking brake has been applied or
released. It then goes out or remains lit.
The electric parking brake is malfunctioning, e.g. because of
overvoltage or undervoltage.
X Remove the cause for the overvoltage or undervoltage, e.g. by
charging the battery or restarting the engine.
X Engage or release the electric parking brake.
If it remains impossible to apply or release the electric parking
brake:
X Switch off the ignition and turn it back on.
X Engage or release the electric parking brake.
If the electric parking brake still cannot be released:
X Consult a qualified specialist workshop. The display message is only shown while the vehicle is in motion.
The yellow
! warning lamp lights up and the red F (USA
only)/ ! (Canada only) indicator lamp flashes.
It is not possible to apply the electric parking brake manually.
X Shift the transmission to P.
X Visit a qualified specialist workshop. F(USA
only)!(Canada
only)
Turn On the
Ignition to
Release the
Parking Brake The red
F (USA
only)/ ! (Canada only) indicator lamp lights
up.
You attempted to release the electric parking brake while the
ignition was switched off.
X Turn the SmartKey to position 1 in the ignition lock.206
Display messages
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
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