check engine MERCEDES-BENZ C-CLASS COUPE 2011 Owner's Guide

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 engin emay
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 tan
khas been run dry
(Y page 157).
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 no tbe
checked. 8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated when the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the
star
toft he scale. The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X
Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Apply the parking brake.
X Consult a qualified specialist workshop. 280
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 Let the engine and coolant cool down.
X Check the coolant level and top up the coolant (Y page 303).
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. ?
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.
The engine is not being cooled sufficiently and may be damaged.
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 Let the engine and coolant cool down.
X Check the coolant level and top up the coolant (Y page 303).
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. Warning and indicator lamps in the instrument cluster
281On-board computer and displays Z

X
Pull release lever :on the bonnet.
The bonnet is released.
! Make sure that the windscreen wipers are
not folded away from the windscreen .Oth-
erwise, you could damage the windscreen
wipers or the bonnet. X
Reach into the gap, pull bonnet catch han-
dle ;up and lift the bonnet.
If you lift the bonnet by approximately
40 cm, the bonnet is opened and held open
automatically by the gas-filled strut.
Closing the bonnet G
WARNING
Make sure tha tnobody can become trapped
as you close the bonnet. 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. Open it again and close
it with a little more force. Engine oil
Notes on the oil level Depending on driving style, the vehicle con-
sumes a maximum of 0.8 l oil per 1000 km.
The oil consumption may be higher than this
when the vehicle is new or if you frequently
drive at high engine speeds.
Checking the oil level using the oil dip-
stick
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. Example: vehicles with a petrol engine302
Engine compartmentMaintenance and care

Example: vehicles with a diesel engine
X
Pull oil dipstick :outoft he 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.
The oil level is correct if the level is between
MIN mark =and MAX mark ;.
X Top up the oil if necessary.
Adding engine oil 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. 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. Example: engine oil cap X
Turn cap :anti-clockwise and remove it.
X Top up with the amount of oil required.
Fill carefully to the maximum mark on the oil
dipstick.
i Depending on the engine, the difference
between the minimum mark and the maxi-
mum mark is approximately 1.5 – 2 litres.
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic con-
verter. Have excess oil siphoned off.
For further information on engine oil, see
(Y page 355).
X Replace cap :on the filler neck and
tighten clockwise.
Ensure that the cap locks into place
securely. Checking and adding other service
products
Checking the coolant level Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
X
Turn the key to position 2(Y page 137) in
the ignition lock.
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 137).
X Check the coolant temperature display in
the instrument cluster. G
WARNING
The cooling system is pressurised. Therefore,
only unscrew the cap once the engine has
cooled down. The coolant temperature gauge
must display less than 70 †.Otherwise, you
could be scalded if hot coolant escapes. Engine compartment
303Maintenance and care Z

water
.Consult a doctor if
necessary. Wear eye protection.
Keep children away.
Observe this Owner's Man-
ual.
H
Environmental note Batteries contain pollutants.
It is against the law to dis-
pose of them with the house-
hold rubbish. They must be
collected separately and
recycled in an environmen-
tally responsible manner. Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop, e.g. a
Mercedes-Benz Service
Centre, or to a special col-
lection point for old batter-
ies.
G
WARNING
For safety reasons, Mercedes-Benz recom-
mends that you 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.
! Switch off the engine and remove the key
before disconnecting the terminal clamps
from the battery. On vehicles with KEY-
LESS-GO, make sure that the ignition is
switched off. Check that all the indicator
lamps in the instrument cluster are off. You
may otherwise destroy electronic compo-
nents, such as the alternator.
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.
Mercedes-Benz recommends that you do not
carry out work on batteries yourself, e.g.
removing or charging. Have this work per-
formed at a qualified specialist workshop, e.g.
a Mercedes-Benz Service Centre. Installation location of the battery
Your vehicle is equipped with a battery in the
engine compartment. It is fitted in front of the
front bulkhead on the right-hand side of the
vehicle when viewed in the direction of travel. 326
BatteryBreakdown assistance

Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-
starting device.
X Slide cover :of positive terminal ;in the direction of the arrow.
X Connec tpositive terminal ;on your vehicle to positive terminal =of donor battery B
using the jump lead, beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ?of donor battery Bto earth point Aof your vehicle using
the jump lead, connectingt he jump lead to donor battery Bfirst.
X Start the engine.
X Allow the engine to run for a few minutes before disconnecting the jump lead.
X First, remove the jump lead from earth point Aand negative terminal ?, then from positive
terminal ;and positive terminal =, each time disconnecting from the contacts on your
own vehicle first.
X After removing the jump lead, close cover :on positive terminal ;.
X Have the battery checked at a qualified specialist workshop, e.g. a Mercedes-Ben zService
Centre. The jump-starting procedure is not a standard operating state; therefore, have the
battery checked. Towing and tow-starting
Important safety notes
Observe the legal requirements for the rele-
vant countries when towing and tow-starting. G
WARNING
If you tow the vehicle, you must use a rigid
towing bar if: R
the engine is not running.
R there is a brake system malfunction.
R there is a malfunction in the power supply
or the vehicle's electrical system.
The power assistance for the steering and the
brake force booster do not work when the
engine is not running. You will need more
force to steer and brake, you may have to
depress the brake pedal with maximum force. 330
Towing and tow-startingBreakdown assistance

Before changing a fuse
X Park the vehicle and apply the parking
brake.
X Switch off all electrical consumers.
X Remove the key from the ignition lock.
The fuses are located in various fuse boxes:
R fuse bo xinthe engine compartmentont he
left-hand side of the vehicle, when viewed
in the direction of travel
R fuse box in the boot on the right-hand side
of the vehicle, when viewed in the direction
of travel
The fuse allocation chart is located in the
vehicle tool kit (Y page 315) in the stowage
compartment under the boot floor. Fuse box in the engine compartment
X Make sure that the windscreen wipers are
turned off. G
WARNING
Make sure that the windscreen wipers are
turned off and the key is pulled out of the igni-
tion lock before you open the cover of the fuse
box. Otherwise, the windscreen wipers and
the wiper rods above the cover could be set
in motion. This could lead to you or others
being injured by the wiper rods.
X Open the bonnet (Y page 301). X
Remove any existing moisture from the
fuse box using a dry cloth.
X Take lines ;from the guides.
X To open: open clamps :.
X Remove the fuse box cover forwards.
! Make sure that no moisture can enter the
fuse box when the cover is open.
X To close: check whether the rubber seal is
lying correctly in the cover.
X Insert the cover at the rear of the fuse box
into the retainer.
X Fold down the cover and close clamps :.
X Secure lines ;in the guides.
! The cover must be fitted properly, other-
wise moisture or dirt could impair the func-
tion of the fuses.
X Close the bonnet (Y page 302). Fuse box in the boot
X Open the boot lid (Y page 85). X
To open: release cover :at the top and
open it downwards in the direction of the
arrow. 334
Electrical fusesBreakdown assistance