2012 MERCEDES-BENZ B-CLASS Owners Manual

Engine
Problem Possible causes/consequences and
M Solutions;
The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, for example:
R
in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system
R in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you must immediately visit a qualified
specialist workshop as
soon as the yellow Check Engine warning
lamp lights up. This depends on the locally applicable legal
requirements. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving. æ
The yellow reserve fuel
warning lamp lights up
while the engine is
running.
The fuel level has dropped into the reserve range.
X
Refuel at the nearest gas station. æ
The yellow reserve fuel
warning lamp flashes
while the engine is
running.
The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
X
Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed:
close the

fuel filler
cap.
X If the fuel filler cap is closed: visit a qualified specialist
workshop. ?
The red coolant
warning lamp lights up
while the engine is
running and
the

coolant
temperature gage is at
the start of the scale. The temperature sensor for the coolant temperature gage is
defective.
The coolant
temperature
is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X Pull over and stop the vehicle safely and switch off the engine,
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. Warning and indicator lamps in the instrument cluster
231
On-board computer and displays Z
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Problem Possible causes/consequences and
M Solutions?
The red coolant
warning lamp
comes
on
while the engine is
running. The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be
malfunctioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X
Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 149).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant (Y page 269). Observe
the warning notes.
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the coolant temperature is
under

248 ‡
(120 †). Otherwise, the engine could be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic. ?
The red coolant
warning lamp
comes

on
while the engine is
running. A warning tone
also sounds. The coolant temperature has exceeded 248 ‡ (120 †). The
airflow
to the
engine radiator may be blocked or the coolant level
may be too low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive
when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Vapor from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Y page 149).232
Warning and indicator lamps in the instrument cluster
On-board computer and displays
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Problem Possible causes/consequences and
M SolutionsX
Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant (Y page 269). Observe
the warning notes.
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X At
coolant temperatures under 248 ‡ (120 †),
drive to the next
qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic. Driving systems
Problem Possible causes/consequences and
M Solutions·
The red distance
warning lamp lights up
while the vehicle is in
motion. A
warning

tone
also sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X
Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action. Warning and indicator lamps in the instrument cluster
233
On-board computer and displays Z
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Useful information ............................
236
Loading guidelines ............................236
Stowage areas .................................. 237
Features ............................................. 247 235Stowage and features
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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).Loading guidelines
G
WARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be

flung around and thereby hit vehicle
occupants. There is a risk of injury,
particularly in the event of sudden braking or
a sudden change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey. G
WARNING
Combustion engines emit poisonous exhaust
gases such as

carbon monoxide. If the tailgate
is open when the engine is running,
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.
The handling characteristics of a laden
vehicle are dependent on the distribution of
the load within the vehicle. For this reason,
you should observe the following notes when
transporting a load:
R Never exceed the maximum permissible
gross vehicle weight or the gross axle weight rating of the vehicle (including
occupants). The
values

are specified on the
vehicle identification plate on the B-pillar of
the driver's door.
R The cargo compartment is the preferred
place to carry objects.
R Position heavy loads as far forwards as
possible and as low down in the cargo
compartment as possible.
R The load must not protrude above the
upper edge of the seat backrests.
R Always place the load against the rear or
front seat backrests. Make sure that the
seat backrests are securely locked into
place.
R Always place the load behind unoccupied
seats if possible.
R Use the cargo tie down rings and the parcel
nets to transport loads and luggage.
R Use cargo tie-down rings and fastening
materials appropriate for the weight and
size of the load.
R Hook in the cargo net when loading.
R The maximum load capacity of the stowage
well under the cargo compartment floor is
55 lbs (25 kg).
R Secure the load with sufficiently strong and
wear-resistant tie-downs. pad sharp edges
for protection.
! Do not position the load on one part of the
folding cargo compartment floor only. The
maximum load capacity of the folding cargo
compartment floor is 220 lbs (100 kg).
Distribute the weight evenly to avoid
damaging the cargo compartment floor.
Place a solid board under the load if
necessary. Please note that the load on the
cargo compartment floor will be increased
when the load is lashed down. 236
Loading guidelines
Stowage and features
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Stowage areas
Stowage space
Important safety notes G
WARNING
If objects in the passenger compartment are
stowed incorrectly, they can slide or be
thrown around and hit vehicle occupants.
There is a risk of injury, particularly in the
event of sudden braking or a sudden change
in direction.
R Always stow objects
so that they cannot be
thrown around in such situations.
R Always make sure that objects do not
protrude from stowage spaces, parcel nets
or stowage nets.
R Close the lockable stowage spaces while
driving.
R Stow and secure objects that are heavy,
hard, pointy, sharp-edged, fragile or too
large in the cargo compartment.
Observe the loading guidelines (Y page 236).
Stowage compartments in the front Glove box
X
To open: pull handle :
and open glove box
flap ;.
X To close: fold glove box flap ; upwards
until it engages.
i There is a pen holder at the top of the
glove box flap. Eyeglasses compartment
X
To open: press marking :.
Make sure that the eyeglasses compartment
is always closed

while the vehicle is in motion.
Stowage compartment in the center
console X
To open: press the marking on cover :.
i Depending on the vehicle's equipment,
there is an open instead of a closed
stowage compartment or

an ashtray in the
center console. Stowage areas
237
Stowage and features Z
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Stowage compartment in front of the
armrest (vehicles with automatic
transmission)
X
To open: press the marking on cover :.
i You can remove
the non-slip mat and the
insert for cleaning. When removing the
insert you will have to overcome some
slight resistance.
Stowage compartment under the armrest X
To open: on vehicles with moveable
armrests, make sure that the armrest is in
the rearmost position.
X Press button : and fold the armrest up.
i Depending on the vehicle's equipment, a
USB connection and

an AUX IN connection
or a Media Interface are installed in the
stowage compartment. A Media Interface
is a universal interface for mobile audio
equipment, e.g. for an iPod ®
or MP3 player
(see the separate COMAND Operating
Instructions). Stowage compartment under the driver's
seat and front-passenger seat G
WARNING
If you exceed the maximum load for the
stowage compartment, the cover may not be
able to restrain the items. Items may be
thrown out of the stowage compartment and
hit vehicle occupants.

There is a risk of injury,
particularly in the event of sudden braking or
a sudden change in direction.
Never exceed the maximum permissible load
for the stowage compartment. Stow and
secure heavy objects in the cargo
compartment.
The maximum permissible load of the
stowage compartment is 2.6 lbs (1.5 kg). X
To open: pull handle : up and fold
cover ; forwards.
Stowage space in the rear Stowage compartment in the rear center
console238
Stowage areas
Stowage and features
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