open bonnet MERCEDES-BENZ B-CLASS HATCHBACK 2011 User Guide

Display messages Possible causes/consequences and
M Solutions
A The tailgate is open.
G WARNING
Whe nthe 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 bonnet is open.
G WARNING
The open bonnet may block your view when the vehicle is in
motion.
There is a risk of accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Engage the electric parking brake.
X Close the bonnet. C At least one door is open.
Awarning tone also sounds.
X Close all doors. j
Check trailer
hitch lock The trailer tow hitch is no
tcorrectly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Engage the electric parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 183).
Otherwise, the trailer may detach itself. D
Power
steering mal‐
function See Own‐
er's Manual The power steering assistance is faulty. You will need to use more
force to steer.
Aw
arning tone also sounds.
X Chec kwhether 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. 230
Display messagesOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
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 mal-
functioning.
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 Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Engage the electric parking brake.
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant (Y page 265).
Observe the warning notes as you do so.
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
under 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving on
mountain roads and stop-start traffic. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 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 compartmen tto
catch fire.
Stea mfrom the overheated engine can also cause serious burns
which can occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Engage the electric parking brake. 240
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Useful information
i This Owner's Manual describes all models
and all standard and optional equipment
available to your vehicle at the time of pub-
lication of the Owner's Manual. Country-
specific deviations are possible. Please
note that your vehicle may not be equipped
with all features described. This also
applies to safety-relevan tsystems and
functions.
i Please read the information on qualified
specialist workshops (Y page 22).Engine compartment
Bonnet
Opening the bonnet G
WARNING
Do no tpull the release leve rwhile the vehicle
is in motion. If you do so, the bonnet may open
up and block your view. G
WARNING
There is a risk of injury if the bonnet is open,
even if the engine is not running.
Some engine components can become very
hot.
To avoid the risk of burns, only touch those
components described in the Owner's Manual
and observe the relevant safety notes. G
WARNING
The radiator fan between the radiator and the
engine can start automatically, even if the key
has been removed from the ignition lock. For
this reason, you must not reach into the fan
rotation area. You could otherwise be injured. Vehicles with
apetrol engine: The elec-
tronic ignitio nsystem uses high voltage. For
this reason, you mus tnever touch ignition
system components (ignition coil, ignition
cables, spark plug connectors or test socket)
while:
R the engine is running
R the engine is being started
R the ignition is switched on and the engine
is being cranked by hand
You could otherwise suffer an electric shock
and be seriously or even fatally injured.
Vehicles with adiesel engine: The elec-
tronic injection control uses high voltage. For
this reason, you must never touch injection
system components while:
R the engine is running
R the engine is being started
R the ignition is switched on
You could otherwise suffer an electric shock
and be seriously or even fatally injured. G
WARNING
The windscreen wipers and wiper linkage
could be set in motion.
When the bonnet is open, you or others could
be injured by the wiper linkage.
Make sure that the windscreen wipers are
switched off and that the key has been pulled
out of the ignition lock before opening the
bonnet.
! Make sure that the windscreen wipers are
not folded away from the windscreen .Oth-
erwise, you could damage the windscreen
wipers or the bonnet. 262
Engine compartmentMaintenance and care

X
Make sure that the windscreen wipers are
switched off.
X Pull release lever :on the bonnet.
The bonnet is released. X
Reach into the gap between the bonnet and
the radiator grille and press bonnet catch
lever ;to the left.
X Raise the bonnet. X
Pull support strut ?out of bracket A.
X Lift up support strut ?and insert it into
yellow retaining clip =. Closing the bonnet G
WARNING
Make sure that nobody can become trapped
as you close the bonnet.
X Raise the bonnet slightly and, at the same
time, remove support strut ?from yellow
retaining clip =.
X Swing support strut ?down and press it
into bracket Auntil it engages.
X Lower the bonnet and let it fall from a
height of approximately 20 cm.
X Check that the bonnet has engaged prop-
erly.
If the bonnet can be raised slightly, it is not
properly engaged. Do not press the bonnet
closed. Open the bonnet again and close it
with a little more force. Engine oil
Notes on oil level Depending on your driving style, the vehicle
consumes up to 0.8 l of oil per 1,000 km. The
oil consumption may be higher than this when
the vehicle is new or if you frequently drive at
high engine speeds.
Depending on the engine, the oil dipstick may
be installed at a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly: wait about 30 minutes
before carrying out the measurement. Engine compartment
263Maintenance and care Z

Otherwise, the vehicle's electronic sys-
tem may be damaged.
R in vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away. You
can then no longer move the vehicle.
The battery and the cover of the positive
terminal clamp must be fitted securely dur-
ing operation.
In order for the battery to achieve the maxi-
mum possible service life, it must always be
sufficiently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the
vehicle. In such cases, have the battery dis-
connected at a qualified specialist workshop.
You can also charge the battery with a
charger recommended by Mercedes-Benz.
For more information, please contact a quali-
fied specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked up for a long period of time.
i When you park the vehicle, remove the
key if you do not require any electrical con-
sumers. The vehicle will then use very little
energy, thus conserving battery power.
i If the power supply has been interrupted,
e.g. if the battery was discharged, you must
carry out the following tasks:
R set the clock (audio system/COMAND
Online, see the separate operating
instructions).
R reset the function for automatically fold-
ing the exterior mirrors in/out by folding
the mirrors out once (Y page 92). Charging the battery
G
WARNING
Only charge the battery in a well-ventilated
area. As the battery is being charged, gases
can escape and generate minor explosions.
This could injure you and other persons or
cause damage to the paintwork or acid cor-
rosion on the vehicle.
You can obtain information on battery charg-
ers which allow the battery to be charged
while still installed from a qualified specialist
workshop. G
WARNING
There is a risk of acid burns during the charg-
ing process due to the gases which escape
from the battery. Do not lean over the battery
during the charging process. G
WARNING
Battery acid is caustic. Avoid contact with the
skin, eyes or clothing.
! Only charge the installed battery with a
battery charger which has been tested and
approved by Mercedes-Benz.T hese battery
chargers allow the battery to be charged
while still installed in the vehicle.
! Only use battery chargers with a maxi-
mum charging voltage of 14.8 V.
! Only charge the battery using the jump-
start connection point.
The jump-starting connection point is in the
engine compartment (Y page 283).
Read the battery charger's operating instruc-
tions before charging the battery.
X Open the bonnet (Y page 262).
X Connect the battery charger to the positive
terminal and earth point in the same order
as when connecting the donor battery in
the jump-starting procedure
(Y page 283). 282
BatteryBreakdown assistance

Jump-starting
G
WARNING
There is a risk of acid burns when jump-starting a vehicle due to the gases which escape from
the battery. Do not lean over the battery while the engine is being jump-started. G
WARNING
Gases escaping from the battery during jump-starting may cause minor explosions. Avoid cre-
ating sparks. Keep naked flames away from the battery, and do not smoke.
Comply with safety precautions when handling batteries. You will find these under "Battery (vehi-
cle)" in the index. G
WARNING
Non-combusted fuel can collect in the exhaust system and ignite. There is a risk of fire. Avoid
repeated and lengthy starting attempts.
! Avoid repeated and lengthy starting attempts. Otherwise, the catalytic converter could be
damaged by the non-combusted fuel.
Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or ajump-starting device.
R You may only jump-start the vehicle when the engine and catalyti cconverter are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed from batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start.T his charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R the jump leads are not damaged.
R bare parts of the terminal clamp do not come into contact with other metal parts while the
jump leads are connected to the battery.
R the jump leads cannot come into contact with parts such as the V-belt pulley or the fan.
These parts move when the engine is started and while it is running.
X Secure the vehicle by applying the electric parking brake.
X Manual transmission: engage neutral.
X Automatic transmission: shift the transmission to position P.
X Turn the key to position 0in the ignition lock and remove it.
X Switch off all electrical consumers (e.g. radio, blower, etc.).
X Open the bonnet (Y page 262). Jump-starting
283Breakdown assistance Z

traced and rectified at a qualified specialist
workshop.
! Only use fuses tha thave been approved
for Mercedes-Ben zvehicles and which
have the correct fuse rating for the system
concerned. Only use fuses marked with an
"S". Components or systems could other-
wise be damaged.
The fuses in your vehicle serve to close down
faulty circuits. If afuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Blown fuses must be replace dwith fuses of
the same rating, which you can recognise by
the colour and fuse rating. The fuse ratings
are listed in the fuse allocation chart.
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified spe-
cialist workshop, e.g. a Mercedes-Benz
Service Centre. Before replacing a fuse
X Park the vehicle and apply the electric park-
ing brake.
X Switch off all electrical consumers.
X Turn the key to position 0in the ignition
lock and remove it (Y page 127). All indi-
cator lamps in the instrumen tcluster must
be off.
The fuses are located in various fuse boxes:
R fuse box in the engine compartmen tonthe
left-hand side of the vehicle, when viewed
in the direction of travel
R fuse box in the front-passenger footwell
The fuse allocation chart is on the fuse box in
the front-passenger footwell (Y page 275).Fuse box in the engine compartment
! Make sure that no moisture can enter the
fuse box when the cover is open. !
When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
or dirt could otherwise impair the operation
of the fuses. X
Open the bonnet (Y page 262).
X Remove any existing moisture from the
fuse box using a dry cloth.
X To open: open clamps ;.
X Fold cover :upwards in the direction of
the arrow and remove it. X
To close: check whether the seal is lying
correctly in cover :.
X Insert cover :at the back into openings
= on the fuse box.
X Fold down cover :.
X Hook clamps ;into the fuse box and
close.
X Close the bonnet (Y page 263).288
Electrical fusesBreakdown assistance