check engine MERCEDES-BENZ GLC COUPE 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 41).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 been run dry (Y page 164).
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.
Operation of the auxiliary heating is deactivated if the fuel level drops into the
reserve range.
X Refuel at the nearest filling station. 286
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 167).
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 329).
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 167).
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 329).
X If you have to top up the coolant frequently, have the engine cooling system
checked. 288
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
291On-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. 326
Engine compartmentMaintenance and care

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.
Hybrid vehicles: make sure that you read the
separate Owner's Manual. You could otherwise
fail to recognise dangers, e.g. due to high volt-
age.
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 be installed 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 If the engine is not at normal operating tem-
perature, e.g. if the engine was only started
briefly, wait approximately 30 minute sbefore
carrying out the measurement
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 :. Engine compartment
327Maintenance and care Z

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 327).
Further information on engine oil (Y page 377). 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 328
Engine compartmentMaintenance and care

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 144).
or
X Press the Start/Stop button twice on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function (Y page 144).
X Check the coolant temperature display on the
instrument cluster (Y page 229).
The coolant temperature must be below
70 †. X
Turn the key to position 0in the ignition lock
(Y page 144).
or X Press the Start/Stop button once on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function (Y page 144).
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 378).
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) Engine compartment
329Maintenance and care Z

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
! Make sure:
R the side windows and sliding sunroof are
closed completely.
R the blower is switched off
R the windscreen wiper switch is at position
0
R the 360° camera or the reversing camera is
switched off.
The vehicle could otherwise be damaged. Care
331Maintenance and care Z

The highly flammable gas mixture is created
while the battery is charging and when jump-
starting.
Always make sure that neither you nor the bat-
tery is electrostatically charged. Electrostatic
charge is created, for example:
R by wearing synthetic-fibre clothing
R by friction between clothing and the seat
R if you pull or push the battery across carpet or
other synthetic materials
R if you rub the battery with a cloth G
WARNING
During the charging process, a battery produ- ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a
connected battery does not come into con- tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
R When jump-starting, make sure that the
battery poles with identical polarity are
connected.
R It is particularly important to observe the
described order when connecting and dis-
connecting the jump leads.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once.
All vehicles: 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 anenvironmentally responsible
recycling system. Dispose of batteries in an
environmentally responsible
manner. Take discharged
batteries to a qualified spe-
cialist workshop 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 work- shop for more information.
! Always have work on the batteries carried
out at a qualified specialist workshop. Should
it, in exceptional circumstances, be abso-
lutely necessary to disconnect the 12-volt
battery yourself, please observe the follow-
ing:
R Secure the vehicle to prevent it from rolling
away.
R Switch off the ignition
R Disconnect the negative terminal first and
then the positive terminal
The transmission is locked in position Pafter
disconnecting the battery.
After the work is completed, securely refit the battery and the postive terminal cover.
Comply with safety notes and take protective
measures when handling batteries. Risk of explosion.
Fire, naked flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks. 346
Battery (vehicle)Breakdown assistance

Electrolyte or battery acid is corro-
sive. Avoid contact with the skin,
eyes and clothing.
Wear suitable protective clothing; in
particular, gloves, an apron and a
face mask.
Immediately rinse electrolyte or acid
splashes off with clean water. Con-
sult a doctor if necessary. Wear eye protection.
Keep children at a safe distance.
Observe this Owner's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you use only batteries that have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the battery be damaged in the event of an accident.
In order for the battery to achieve the maximum possible service life, it should always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle. In such cases, have the battery disconnected ata qualified specialist workshop. However, you
can also charge the battery with a charger rec-
ommended by Mercedes-Benz. For more infor-
mation, please contact a qualified 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 an exten-
ded period. Consult a qualified specialist work-
shop if you wish to leave your vehicle parked up for a long period of time.
When you park the vehicle, remove the key if you
do not require any electrical consumers. The
vehicle will then use very little energy, thus con- serving battery power. Charging the 12 V battery
Vehicles with a lithium-ion battery:
! Only use battery chargers with a maximum
charging voltage of 14.4 V.
All ve hicles except vehicles with a lithium-
ion battery:
! Only use battery chargers with a maximum
charging voltage of 14.8 V. G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off
battery acid thoroughly with plenty of clean
water and seek medical attention at once. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
All vehicles: ! Only charge the battery using the jump-start
connection point.
The jump-starting connection point is in the
engine compartment (Y page 348).
X Open the bonnet.
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 process (Y page 348). Battery (vehicle)
347Breakdown assistance Z