check engine MERCEDES-BENZ B-CLASS HATCHBACK 2011 Owner's Manual

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 yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. ESP
®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X Only depress the accelerator pedal as far as necessary when
pulling away.
X Accelerate more gently while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
For exceptions, see: (Y page 66).å
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. ESP
®
and ESP ®
trailer stabilisation are deactivated. ESP ®
will not
stabilise the vehicle if it starts to skid or if awheel starts to spin.
G WARNING
If ESP ®
is deactivated, the vehicle's stability during standard driv-
ing manoeuvres is reduced.
There is a risk of accident.
X Reactivate ESP ®
.
For exceptions, see: (Y page 66).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, BAS PLUS, PRE-SAFE ®
, the HOLD function, hill start
assist, the adaptive brake lights and ESP ®
trailer stabilisation are
not available due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
ESP ®
will not stabilise the vehicle if it starts to skid or if a wheel
starts to spin.
The brake system continues to function normally, but without the
functions listed above.
If ESP ®
is deactivated or not operational, the vehicle's stability
during standard driving manoeuvres is reduced.
There is a risk of accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 236
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
!
The red indicator lamp
for the electric parking
brake flashes and/or
the yellow warning
lamp for the electric
parking brake lights up.
The electric parking brake is temporarily malfunctioning or is
defective.
X
Observe the additional display messages in the multifunction
display. 6
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint Sys-
tem).
G WARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered at all.
There is an increased risk of injury.
X Drive on carefully.
X Have SRS checked at a qualified specialist workshop immedi-
ately.
For further information on occupant safety, see (Y page 38).Engine
Problem Possible causes/consequences and
M Solutions
;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running. There may be a fault, for example:
R
in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
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. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 143).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need not be
checked. 238
Warning and indicator lamps in the instrument clusterOn-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

Problem Possible causes/consequences and
M Solutions
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 If the coolant temperature is less than 120 †, you can continue
driving 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. Driving systems
Problem Possible causes/consequences and
M Solutions
·
The red distance warn-
ing lamp lights up while
the vehicle is in motion.
The distance to the vehicle in front is too small for the speed
selected.
X Increase the distance. ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion.
Aw
arning 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
241On-board computer and displays Z

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

Checking the oil level using the oil dip-
stick
Example
:vehicles with a petrol engine Example: vehicles with a diesel engine
X
Pull oil dipstick :out of the oil dipstick
tube.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick :into the guide
tube to the stop, and take it out again.
If the level is between MIN mark =and
MAX mark ;, the oil level is correct.
X If the oil level has dropped to MIN mark
= or below, add 0.5to 1.0litre of engine
oil.
Adding engine oil G
WARNING
If engine oil comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any engine oil on hot
engine parts. H
Environmental note
When topping up the oil, take care not to spill
any. If oil enters the soil or waterways, it is
harmful to the environment.
! Only use engine oils and oil filters that
have been approved for vehicles with a
service system. You can obtain a list of the
engine oils and oil filters tested and
approved in accordance with the
Mercedes-Benz Specifications for Service
Products at any Mercedes-Benz Service
Centre.
Damage to the engine or exhaust system is
caused by the following:
R using engine oils and oil filters that have
not been specifically approved for the
service system
R changing the engine oil and oil filter after
missing the change interval required by
the service system
R using engine oil additives
! Do not add too much oil. Topping up with
too much engine oil can result in damage
to the engine or to the catalytic converter.
Have excess engine oil siphoned off. Example: engine oil filler cap
X
Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or under the MIN mark
on the oil dipstick, add 0.5 to 1.0 litre of
engine oil. 264
Engine compartmentMaintenance and care

X
Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks into place
securely.
X Chec kthe oil level again with the oil dip-
stick (Y page 264).
Further information on engine oil
(Y page 314). Checking and adding other service
products
Checking the coolant level G
WARNING
The cooling system is pressurised. Therefore,
only unscrew the cap once the engine has
cooled down. The coolant temperature dis-
play must show less than 40 †. Otherwise,
you could be scalded if hot coolant escapes.
! The coolant level must only be checked
and corrected when the engine has cooled
down (coolant temperature under 40 †).
Checking the coolant level when the cool-
ant temperature is over 40 † can lead to
damage to the engine or engine cooling
system. X
Park the vehicle on a level surface.
Only check the coolant level if the vehicle
is on a level surface and the engine has
cooled down.
X Turn the key to position 2in the ignition
lock (Y page 127). X
Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
40 †.
X Turn the key to position 0(Ypage 127) in
the ignition lock.
X Slowly turn cap :half a turn anti-clock-
wise to allow excess pressure to escape.
X Turn cap :further anti-clockwise and
remove it.
If the coolant is at the level of marker bar
= in the filler neck when cold, there is
enough coolant in coolant expansion
tank ;.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-
Benz.
X Replace cap :and turn it clockwise as far
as it will go.
For further information on coolant, see
(Y page 316).
Topping up the windscreen washer sys-
tem/headlampc leaning system G
WARNING
Windscreen washer fluid/antifreeze is highly
flammable. Avoid spilling windscreen washer
fluid/antifreeze on hot engine components as
it can ignite and burn. Severe burns could be
the result. Engine compartment
265Maintenance and care Z

Flat tyre
Preparing the vehicle
Your vehicle may be equipped with:
R MOExtended tyres (tyres with run-flat char-
acteristics) (Y page 276)
R a TIREFIT kit
R an emergency spare wheel (only for certain
countries)
You can find information on changing/fitting
wheels in the "Wheel change" section
(Y page 298).
i Vehicle preparation is no tnecessary on
vehicles with MOExtended tyres.
i Vehicles with MOExtended tyres are not
equipped with a TIREFIT kit at the factory.
It is therefore recommended that you addi-
tionally equip your vehicle with a TIREFIT kit
if you fit tyres that do not feature run-flat
characteristics, e.g. winter tyres. A TIREFIT
kit can be obtained from a qualified spe-
cialist workshop.
X Stop the vehicle as far away as possible
from traffic on solid, non-slippery and level
ground.
X Switch on the hazard warning lamps.
X Apply the electric parkin gbrake manually
(Y page 145).
X Bring the front wheels into the straight-
ahead position.
X Vehicles with manual transmission:
engage first or reverse gear.
X Vehicles with automatic transmission:
move the DIRECT SELECT lever to P.
X Switch off the engine.
X Remove the key from the ignition lock.
X All occupants must get out of the vehicle.
Make sure that they are not endangered as
they do so.
X Make sure that no one is near the danger
area whilst a wheel is being changed .Any-
one who is not directly assisting in the wheel change should, for example, stand
behind the barrier.
X Ge tout of the vehicle. Pay attention to traf-
fic conditions when doing so.
X Close the driver's door.
X Place the warning triangle ( Ypage 274) a
suitable distance away. Observe legal
requirements. MOExtended tyres (tyres with run-flat
characteristics)
G
WARNING
When driving in emergency mode, the driving
characteristics deteriorate, e.g. when corner-
ing, accelerating quickly and when braking.
There is a ris kofaccident.
Do not exceed the state dmaximum speed.
Avoid abrupt steering and driving manoeu-
vres, and driving ove robstacles (kerbs, pot-
holes, off-road). This applies in particular to a
laden vehicle.
Stop driving in emergency mode if:
R you hear banging noises.
R the vehicle starts to shake.
R you see smoke and smell rubber.
R ESP ®
is intervening constantly.
R there are tears in the sidewalls of the tyre.
After driving in emergency mode, have the
wheel rims checked at a qualified specialist
workshop with regard to their further use. The
faulty tyre must be replaced.
With MOExtended tyres (tyres with run-flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tyres.
MOExtended tyres may only be used in con-
junction with an activated tyre pressure loss
warning system.
The driving distance possible is 80 km when
the vehicle is partially laden, and 30 km when
the vehicle is fully laden. 276
Flat tyreBreakdown assistance

Battery acid is caustic.
Avoid contact with the skin,
eyes or clothing.
Wea
rsuitable protective
clothing, in particular
gloves, an apro nand a face
mask.
Immediately rinse acid
splashes off with clean
water. Consult a doctor if
necessary. Wear eye protection.
Keep children away.
Observe this Owner's Man-
ual.
G
WARNING
For safety reasons, Mercedes-Benz recom-
mends tha tyou only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehi-
cle occupants from suffering acid burns
should the battery be damaged in the event
of an accident.
To prevent acid burns, observe the following
safety notes when handling batteries:
R do not lean over the battery.
R do not place any metal objects on a battery.
Otherwise, you could cause a short circuit
and the battery's gas mixture could ignite.
R make sure that you do not create an elec-
trostatic charge, e.g. by wearing synthetic
clothing or as a result of friction on fabrics.
Therefore, you should not pull or slide the
battery over carpets or other synthetic
materials. R
never touch the battery first. To discharge
a possible electrostatic charge, step out of
the vehicle first and touch the bodywork.
R do not wipe the battery using a cloth. The
battery may explode as a result of electro-
static charge or due to flying sparks. H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system.
Dispose of batteries in an
environmentally responsible
manner
.Take discharged
batteries to a qualified spe-
cialis tworkshop or to a col-
lection point for used batter-
ies.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Service
Booklet or contact a qualified specialist
workshop for more information.
! You should have all work involving the
battery carried out at aqualified specialist
workshop. In the exceptional case that it is
necessary for you to disconnect the battery
yourself, make sure that:
R you switch off the engine and remove the
key. On vehicles with KEYLESS-GO,
ensure that the ignition is switched off.
Chec kthat all the indicator lamps in the
instrument cluster are off. Otherwise,
electronic components, such as the
alternator, may be damaged.
R you first remove the negative terminal
clamp and then the positive terminal
clamp. Never swap the terminal clamps. Battery
281Breakdown assistance Z