check engine MERCEDES-BENZ C-CLASS CABRIOLET 2016 Service Manual

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions !
N
The red indicator lamp for the electric parking brake flashes or is lit and/or the
yellow warning lamp for the electric parking brake is lit.
X Observe the additional display messages on the multifunction display. 6
N
The red restraint system warning lamp is lit while the engine is running.
The restraint system is malfunctioning.
G WARNING
The airbags or belt tensioners may either be triggered unintentionally or, in the
event of an accident, may not be triggered.
This poses an increased risk of injury.
X Observe the additional display messages on the multifunction display.
X Drive on carefully.
X Contact a qualified specialist workshop immediately and have the restraint sys-
tem checked.
Further information about the restraint system (Y page 42).Engine
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ;
N
The yellow engine diagnostics warning lamp lights up while the engine is run-
ning.
A fault may exist with the following, for example:
R Engine management
R Fuel injection system
R Exhaust system
R Ignition system (for vehicles with petrol engines)
R Fuel system
The emission limit values may be exceeded and the engine may be running in
emergency mode.
X Consult a qualified specialist workshop immediately.
Vehicles with a diesel engine: the fuel tank has run dry (Y page 156).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emergency running
mode is cancelled. The vehicle does not have to be checked. 8
N
The yellow reserve fuel warning lamp is on while the engine is running.
The fuel level has dropped into the reserve range.
X Refuel at the nearest filling station. 278
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
M Solutions ?
N
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 on the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 159).
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, making sure to observe the
warning notes (Y page 312).
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 below 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 in mountainous terrain
and stop-start traffic. ?
N
The red coolant warning lamp comes on while the engine is running. 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.
Never drive with an overheated engine. Driving when your engine is overheated
can cause any fluids that may have leaked into the engine compartment to catch fire.
In addition, steam from an overheated engine can cause serious burns, which can
occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages on the multifunction display.
X Stop the vehicle immediately, paying attention to road and traffic conditions,
and switch off the engine.
X Secure the vehicle against rolling away (Y page 159).
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, making sure to observe the
warning notes (Y page 312).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 280
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Vehicle
Warning/
indicator
lamp
N N
Signal type
Possible causes/consequences and M
MSolutions Ð
N
The red power steering warning lamp is lit while the engine is running.
The power steering assistance is faulty.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident.
X Check whether you are able to apply the extra force required.
If you are able to steer safely:
X Drive on carefully.
X Consult a qualified specialist workshop immediately.
If you are unable to steer safely:
X Do not drive on.
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
283On-board computer and displays Z

X
With your hand flat, push down the active
bonnet :in the area around the hinges on
both sides (arrows).
Do so until you feel the active bonnet :
engage.
If you can raise the active bonnet slightly at the rear in the area around the hinges, it is not
engaged correctly. Repeat the step.
Opening the bonnet G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
When the bonnet is open, and the windscreen wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windscreen wipers and
the ignition before opening the bonnet.
! Make sure that the windscreen wipers are
not folded away from the windscreen. Other-
wise, you could damage the windscreen wip-
ers or the bonnet. 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, 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 automat-
ically by the gas-filled struts.
Closing the bonnet X
Lower the bonnet and let it fall from a height
of approximately 20 cm.
X Check that the bonnet has engaged properly.
If the bonnet can be raised slightly, it is not
properly engaged. Open it again and close it
with a little more force. Radiator
Do not cover up the radiator. Do not use thermal mats, insect protection covers or anything sim-
ilar. Otherwise, the values of the European on-
board diagnostics may be affected. Some of
these values are required by law and must
always be correct. Engine compartment
309Maintenance and care Z

Engine oil
Important safety notes G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
There are moving components in the engine
compartment. Certain components may con-
tinue to move or suddenly move again even
after the ignition has been switched off, e.g.
the radiator fan. There is a risk of injury.
If you have to carry out work in the engine
compartment:
R switch off the ignition
R never touch the dangerous areas surround-
ing moving components, e.g. the rotation
area of the fan
R remove jewellery and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts. G
WARNING
If engine oil comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Make sure that engine oil does not spill out
over the filler neck. Allow the engine to cool
down and thoroughly clean the components
that have come into contact with engine oil
before you start the engine. G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury. Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade.
General notes Depending on your driving style, the vehicle
consumes up to 0.8 l of 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.
Depending on the engine, the oil dipstick may beinstalled at different locations.
To check the oil level:
R park the vehicle on a level surface
R the engine should be switched off for approx-
imately five minutes if the engine is at normal
operating temperature
R All vehicles (except Mercedes-AMG C 63
and Mercedes ‑AMG C 63 S):if the engine is
not at normal operating temperature, e.g. if
the engine was started only briefly, wait
approximately 30 minutes before carrying out the measurement
Mercedes ‑AMG C 63 and Mercedes ‑AMG C
63 S: The oil level must only be checked when
the engine is at normal operating temperature.
Checking the oil level using the oil dip-
stick Check the oil level with the oil dipstick (exam-
ple)
X Pull oil dipstick :out of the dipstick tube.
X Wipe off oil dipstick :.310
Engine compartmentMaintenance and care

X
Slowly slide oil dipstick :into the guide tube
to the stop and take it out again after approx- imately three seconds.
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, top up with 1.0 lof engine oil.
Topping up 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.
! Use only engine oils and oil filters that are
approved for vehicles with a service system. A list of the engine oils and oil filters that have
been tested and approved in accordance with
Mercedes-Benz Specifications for Service
Products is available at any Mercedes-Benz
Service Centre.
The following cause engine failure or damage
to the exhaust system:
R Use of engine oils and oil filters that have
not been expressly approved for the service
system
R Replacement of engine oil and oil filter after
the replacement interval specified by the
service system has expired
R Use of 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. Top up the engine oil (example) X
Turn cap :anti-clockwise and remove it.
X Top up the engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, top up with 1.0 l of engine oil.
X Replace cap :on the filler neck and turn
clockwise.
Make sure that the cap locks securely into
place.
X Check the oil level again with the oil dipstick
(Y page 310).
Further information on engine oil (Y page 365). Other service products
Important safety notes G
WARNING
Certain components in the engine compart-
ment could be very hot, e.g. the engine, the
radiator and parts of the exhaust system.
There is a risk of injury when accessing the
engine compartment.
As far as possible, allow the engine to cool
down and only touch the components descri- bed in the following. G
WARNING
There are moving components in the engine
compartment. Certain components may con-
tinue to move or suddenly move again even
after the ignition has been switched off, e.g.
the radiator fan. There is a risk of injury.
If you have to carry out work in the engine
compartment:
R switch off the ignition
R never touch the dangerous areas surround-
ing moving components, e.g. the rotation
area of the fan
R remove jewellery and watches
R keep items of clothing and hair, for exam-
ple, away from moving parts. G
WARNING
The cooling system is pressurised, particu-
larly when the engine is warm. If you open the Engine compartment
311Maintenance and care
Z

cap, you could be scalded if hot coolant
sprays out. There is a risk of injury.
Let the engine cool down before you open the cap. Wear gloves and eye protection. Open
the cap slowly to release the pressure. G
WARNING
If you open the bonnet while the engine is
overheating or while there is a fire in the
engine compartment, you could come into
contact with hot gases or other leaking ser-
vice products. There is a danger of injury.
Allow an overheating engine to cool down
before opening the bonnet. If there is a fire in the engine compartment, leave the bonnet
closed and notify the fire brigade.
Checking the coolant level Check the coolant level (example)
X Park the vehicle on a level surface.
Check the coolant level only 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 133).
or
X Press the Start/Stop button twice on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function (Y page 133).
X Check the coolant temperature display on the
instrument cluster (Y page 221).
The coolant temperature must be below
70 †. X
Turn the key to position 0in the ignition lock
(Y page 133).
or X Press the Start/Stop button once on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function (Y page 133).
X Slowly turn cap :half a turn anti-clockwise
and 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 ;.
If the coolant level is approximately 1.5 cm
above marker bar =in the filler neck when
warm, 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.
Further information on coolant (Y page 366).
Topping up the windscreen washer sys-
tem G
WARNING
If windscreen washer concentrate comes into contact with hot components of the engine or
the exhaust system, it can ignite. There is a
risk of fire and injury.
Make sure the windscreen washer concen-
trate does not come into contact with the filler neck. Topping up the windscreen washer system
(example)312
Engine compartmentMaintenance and care

Special service requirements
The prescribed service interval is based on nor-
mal operation of the vehicle. Service work will
need to be performed more often if the vehicle is
operated under arduous conditions or increased loads, for example:
R Regular city driving with frequent intermedi-
ate stops
R If the vehicle is primarily used to travel short
distances
R For frequent use in mountainous terrain or on
poor road surfaces
R If the engine is often left idling for long periods
In these or similar operating conditions, have
the air filter, engine oil and oil filter, for example, changed more frequently. The tyres must be
checked more frequently if the vehicle is oper-
ated under increased loads. Further informationcan be obtained at a qualified specialist work-
shop, e.g. a Mercedes-Benz Service Centre.
Driving abroad An extensive Mercedes-Benz Service network is
also available in other countries. You can obtain further information from any Mercedes-Benz
Service Centre. Care
General notes
! For cleaning your vehicle, do not use any of
the following:
R dry, rough or hard cloths
R abrasive cleaning agents
R solvents
R cleaning agents containing solvents
Do not scrub.
Do not touch the surfaces or protective films
with hard objects, e.g. a ring or ice scraper.
You could otherwise scratch or damage the
surfaces and protective film.
! Do not park up your vehicle for a long period
of time immediately after cleaning, particu-
larly after cleaning the wheel rim with wheel
cleaner. Wheel cleaner may lead to increased corrosion of the brake discs and pads. You
should therefore drive for a few minutes after
cleaning. By heating up the brakes, the brake discs and pads dry. The vehicle can then be
parked up for a long period of time. H
Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man-
ner.
Regular care of your vehicle is a condition for
retaining quality in the long term.
Use care products and cleaning agents recom-
mended and approved by Mercedes-Benz. Washing the vehicle and cleaning the
paintwork
Automatic car wash G
WARNING
Braking efficiency is reduced after the vehicle has been washed. There is a risk of an acci-
dent.
After washing the vehicle, brake carefully
while paying attention to the traffic conditions in order to restore full braking efficiency.
! When DISTRONIC PLUS or the HOLD func-
tion is activated, the vehicle brakes automat- ically in certain situations.
To avoid damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or similar situations:
R when towing away
R in a car wash
! Preferably use car washes with adjustable
high-pressure jets for pre-washing. This cor-
responds with the specifications for cabriolet programmes. In car washes that use high
water pressures, there is a risk that a small
amount of water may leak into the vehicle.
! Make sure that the vehicle is not subse-
quently treated with hot wax.
! Always remove the key before washing the
vehicle in a car wash. Doing so ensures that
the wind deflector on the windscreen
retracts. The wind deflector may otherwise be damaged.
! Make sure: 314
CareMaintenance and care

Cleaning the reversing camera and
360° camera !
Do not clean the camera lens and the area
around the reversing camera or 360° camera
with a high-pressure cleaner. X
Make sure that the vehicle is stationary.
X Turn the key to position 1or 2in the ignition
lock (Y page 133).
or X Press the Start/Stop button once or twice on
vehicles with KEYLESS-GO or the KEYLESS-
GO start function (Y page 133).
X Open the camera cover for cleaning via the
multimedia system; see Digital Owner's Man-
ual.
X To clean the camera: use clean water and a
soft cloth to clean the camera lens :.
When you switch off the ignition, the camera
cover closes automatically.
Cleaning the exhaust tail pipes G
WARNING
The exhaust tail pipe and tail pipe trim can
become very hot. If you come into contact
with these parts of the vehicle, you could burn
yourself. There is a risk of injury.
Always be particularly careful around the
exhaust tail pipe and the tail pipe trim. Allow
these components to cool down before touch-
ing them.
! Do not clean the exhaust pipe with acid-
based cleaning agents, such as sanitary
cleanser or wheel cleaner.
! Mercedes‑
AMG C 63 and Mercedes‑ AMG C
63 S with black exhaust pipes: Black chrome trims must not be polished with a chrome
polish as this will cause them to lose their
black shine. To ensure optimum care, the
trims should be rubbed down with a lightly
oiled cloth after each time the car is washed. Commercially available engine and mainte-
nance oils are suitable for use as oil.
In the event of heavier soiling, you may apply a fine lacquer polish with a microfibre cloth.
Remove any excess polish paste after polish-
ing.
Impurities combined with the effects of road grit
and corrosive environmental factors may cause
flash rust to form on the surface. You can
restore the original shine of the exhaust pipe by cleaning it regularly, especially in winter and
after washing the vehicle.
X Clean the exhaust pipe with a care product
tested and approved by Mercedes-Benz.
Cleaning the trailer tow hitch H
Environmental note
Dispose of oily and greasy cloths in an envi-
ronmentally-responsible manner.
! Do not clean the ball coupling with a high-
pressure cleaner. Do not use solvents.
The ball coupling must be cleaned if it becomes
dirty or corroded.
X Remove rust on the ball, e.g. with a wire
brush.
X Remove dirt with a clean, lint-free cloth or a
brush.
X After cleaning, lightly oil or grease the ball
coupling.
X Check that the vehicle's trailer tow hitch is
working properly.
You can also have the maintenance work on the
ball coupling and the trailer tow hitch carried out
by a qualified specialist workshop. 320
CareMaintenance and care

X
Open the boot lid.
X Swing the boot floor upwards (Y page 300).
X Remove towing eye :.Flat tyre
Preparing the vehicle
Your vehicle may be equipped with: R MOExtended tyres (tyres with run-flat char-
acteristics) (Y page 326)
Vehicle preparation is not necessary on vehi- cles with MOExtended tyres.
R a TIREFIT kit (Y page 325)
R an emergency spare wheel (certain countries
only) (Y page 356)
Vehicles with MOExtended tyres are not equip-
ped with a TIREFIT kit at the factory. It is there-
fore recommended that you additionally equip
your vehicle with a TIREFIT kit if you fit tyres that do not feature run-flat characteristics, e.g. win-
ter tyres. A TIREFIT kit can be obtained from a
qualified specialist workshop.
Vehicles with a Mercedes-Benz emergency call
system that are not equipped with a TIREFIT kit:
in the event of a flat tyre, contact the Customer
Assistance Centre for the Mercedes-Benz emer- gency call system (Y page 304).
Information on changing and fitting a wheel
(Y page 350).
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 Secure the vehicle against rolling
(Y page 159).
X If possible, bring the front wheels into the
straight-ahead position.
X Switch off the engine.
X Remove the key from the ignition lock.
or, on vehicles with KEYLESS-GO start function
or KEYLESS ‑GO:
X Open the driver's door.
The vehicle electronics now have status 0.
This is the same as the key having been
removed.
X Remove the Start/Stop button from the igni-
tion lock (Y page 133).
X Make sure that the passengers are not endan-
gered as they get out of the vehicle. Make
sure that no one is near the danger area while a wheel is being changed. Anyone who is not
directly assisting in the wheel change should,
for example, stand behind the barrier.
X Get out of the vehicle. Pay attention to traffic
conditions when doing so.
X Close the driver's door.
X Place the warning triangle a suitable distance
away (Y page 324). Observe legal require-
ments. Vehicles with MOExtended tyres
(tyres with run-flat characteristics)
General notes With MOExtended tyres (tyres with run-flat char-
acteristics), you can continue to drive your vehi-
cle even if there is a total loss of air in one or
more tyres. The affected tyre must not show any clearly visible damage.
You can recognise MOExtended tyres by the
"MOExtended" marking that appears on the tyre
sidewall. You will find this marking next to the
tyre size designation, the load-bearing capacity
and the speed index.
MOExtended tyres may be used only in conjunc- tion with an activated tyre pressure loss warning system or tyre pressure monitor.
If a tyre pressure loss warning message
appears on the multifunction display:
R observe the instructions in the display mes-
sages (Y page 265)
R check the tyre for damage
R if driving on, observe the following notes
The driving distance possible in run-flat mode is
approximately 80 km when the vehicle is parti-
ally laden and approximately 30 km when the
vehicle is fully laden.
In addition to the vehicle load, the driving dis-
tance possible in run-flat mode depends on the:
R vehicle speed
R road condition
R outside temperature
The driving distance possible in run-flat mode
may be reduced by extreme driving conditions/ manoeuvres, or it can be increased through a
moderate style of driving.
The driving distance possible in run-flat mode iscounted from the moment the tyre pressure loss
warning appears on the multifunction display. 326
Flat tyreBreakdown assistance