check engine MERCEDES-BENZ GLC COUPE 2018 Owner's Guide

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
8NThe yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gage is at the start of the scale.
The temperature sensor for the coolant temperature gage is malfunctioning.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 151).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster261
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe 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 defective.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 151).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 306).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature gage is below the red
marking. Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?N The red coolant warning lamp comes on while the engine is running. A warning
tone also sounds.
The coolant temperature gage has reached the red marking. The airflow to the
engine radiator may be blocked or the coolant level may be too low.
GWARNING
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 compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can occur
just by opening the hood.
There is a risk of injury.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 151).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 306).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
262Warning and indicator lamps in the instrument cluster
On-board computer and displays

Vehicle
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
ÐNThe red power steering warning lamp is lit while the engine is running.
The power steering is malfunctioning.
A warning tone also sounds.
GWARNING
You will need to use more force to steer.
There is a risk of an accident.
XCheck whether you are able to apply the extra force required.
If you are able to steer safely:
XDrive on carefully.
XVisit a qualified specialist workshop immediately.
If you are unable to steer safely:
XDo not drive on.
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster265
On-board computer and displays
Z

To check the engine oil level:
Rpark the vehicle on a level surface
Rthe engine should be switched off for approx-
imately five minutes if the engine is at normal
operating temperature
Checking the oil level using the oil dip-
stick
Example: checking the engine oil level using
the oil dipstick
XPull oil dipstick:out of the dipstick guide
tube.
XWipe off oil dipstick :.
XSlowly 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.
XIf the engine oil level has dropped to MIN mark
=or below, top up with 1.1 US qt (1.0 l) of
engine oil.
Adding engine oil
HEnvironmental note
When adding 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 authorized
Mercedes-Benz Center. The following cause engine failure or damage
to the exhaust system:
RUse of engine oils and oil filters that have
not been expressly approved for the service
system
RReplacement of engine oil and oil filter after
the replacement interval specified by the
service system has expired
RUse of engine oil additives
!Do not add too much oil. adding too much
engine oil can result in damage to the engine
or to the catalytic converter. Have excess
engine oil siphoned off.
Add engine oil (example)
XTurn cap :counter-clockwise and remove it.
XAdd engine oil.
If the oil level is at or below the MIN mark on
the oil dipstick, add 1.1 US qt (1.0 l)of engine
oil.
XReplace cap :on the filler neck and tighten
clockwise.
Ensure that the cap locks into place securely.
XCheck the oil level again with the oil dipstick
(Ypage 305).
Further information on engine oil (
Ypage 363).
Additional service products
Important safety notes
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Engine compartment305
Maintenance and care
Z

Where possible, let the engine cool down andtouch only the components described in the
following.
GWARNING
The engine compartment contains moving
components. Certain components, such as
the radiator fan, may continue to run or start
again suddenly when the ignition is off. There is a risk of injury.
If you need to do any work inside the engine
compartment:
Rswitch off the ignition
Rnever reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
Rremove jewelry and watches
Rkeep items of clothing and hair, for exam-
ple, away from moving parts
GWARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the 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. Slowly
open the cap to relieve pressure.
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
Checking coolant level
Checking the coolant level (example)
XPark the vehicle on a level surface.
Only check the coolant level when the vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 130).
or
XPress the Start/Stop button twice on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function (
Ypage 131).
XCheck the coolant temperature display in the
instrument cluster (Ypage 36).
The coolant temperature must be below
158 ‡ (70 †).
XTurn the SmartKey to position gin the igni-
tion lock (Ypage 130).
or
XPress the Start/Stop button once on vehicles with KEYLESS-GO or the KEYLESS-GO start
function (
Ypage 131).
XSlowly turn cap :half a turn counter-clock-
wise and allow excess pressure to escape.
XTurn cap :further counter-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 0.6 in
(1.5 cm) above marker bar =in the filler neck
when warm, there is enough coolant in expan-
sion tank ;.
XIf necessary, add coolant that has been tested
and approved by Mercedes-Benz.
XReplace cap :and turn it clockwise as far as
it will go.
For further information on coolant, see
(
Ypage 364).
306Engine compartment
Maintenance and care

XMake sure that the vehicle is stationary.
XTurn the SmartKey to position1or2 in the
ignition lock (Ypage 130).
or
XPress the Start/Stop button once or twice on
vehicles with KEYLESS-GO or the KEYLESS-
GO start function (
Ypage 131).
XOpen the camera cover for cleaning via the
multimedia system (see Digital Operator's
Manual).
XTo clean the camera: use clean water and a
soft cloth to clean camera lens :.
When you switch off the ignition, the camera
cover closes automatically.
Cleaning the exhaust pipes
GWARNING
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 bathroom
cleaner or wheel cleaner.
!Mercedes‑AMG GLC 63 and Mercedes‑AMG
GLC 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. For optimal care, the face-
plates should be rubbed with a lightly oiled
cloth after every car wash. Commercially available engine and care oils are suitable for
this.
For heavier soiling, you can apply a fine paint-
work polish with a microfiber cloth. Remove
the excess polish residue after polishing.
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.
XClean the exhaust pipe with a care product
tested and approved by Mercedes-Benz.
Cleaning the trailer tow hitch
HEnvironmental note
Dispose of rags soaked in oil and grease in an
environmentally responsible manner.
!Please note the care instructions in the
trailer coupling manufacturer's operating
instructions.
The ball coupling must be cleaned if it becomes dirty or corroded.
XRemove rust on the ball, e.g. with a wire
brush.
XRemove dirt with a clean, lint-free cloth or a
brush.
XAfter cleaning, lightly oil or grease the ball
coupling.
XCheck 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.
Interior care
Cleaning the display
!For cleaning, do not use any of the following:
Ralcohol-based thinner or gasoline
Rabrasive cleaning agents
Rcommercially-available household cleaning
agents
These may damage the display surface. Do
not put pressure on the display surface when
Care313
Maintenance and care
Z

Flat tire
Preparing the vehicle
Your vehiclemay be equipped with:
RMOExtended tires (tires wit hrun-flat proper -
ties) (Ypage 318)
Vehicl epreparation is no tnecessar yon vehi-
cle swit hMOExtended tires
RaTIREFI Tkit (Ypage 317)
Vehicles equipped wit hMOExtended tires are
no tequipped wit h aTIREFI Tkit at th efactory. It
is therefor erecommended that you additionally
equip your vehicl ewit h a TIREFI Tkit if you moun t
tires that do no tfeature run-flat properties, e.g.
winte rtires . ATIREFI Tkit may be obtained from
a qualified specialist workshop.
Vehicles wit han mbrace system (US Aonly) that
are no tequipped wit h aTIREFI Tkit :in th eevent
of aflat tire, contact th eCustome rAssistanc e
Cente rof th embrace emergenc ycall system
(
Ypage 293).
Information on changing and mounting wheels
(
Ypage 354).
XStop th evehicl eon solid, non-slippery and
leve lground ,as far away as possible from
traffic.
XSwitc hon th ehazard warning lamps.
XSecur eth evehicl eagainst rollin gaway
(Ypage 151).
XIf possible ,brin gth efron twheels int oth e
straight-ahead position .
XSwitchoff th eengine.
XRemove th eSmartKey from th eignition lock.
or, in vehicles withKEY
LESS-GO start-function
or KEYLESS‑ GO
XOpen thedriver' sdoor .
The vehicl eelectronics are no win position
u. whic his th esam eas th eSmartKey having
been removed.
XRemove th eStart/Sto pbutto nfrom th eigni-
tion loc k (Ypage 131).
XMakesure that th eengin ecanno tbe started
via your smartphon e (Ypage 133).
XMakesure that th epassenger sare no tendan -
gered as they do so. Mak esure that no on eis
near th edanger area while awhee lis bein g
changed. Anyon ewho is no tdirectly assisting
in th ewhee lchang eshould, for example ,
stand behind th ebarrier.
XGet out of th evehicle. Pay attention to traffic
condition swhen doin gso.
XClose th edriver' sdoor .
Vehicles with MOExtended tires (tires
with run-flat characteristics)
General notes
Wit hMOExtended tires (tires wit hrun flat char-
acteristics), you can continue to driv eyour vehi-
cle eve nif there is atotal loss of pressur ein on e
or mor etires .The affected tire must no tsho w
any clearly visible damage.
You can recognize aMOExtended tire by th e
MOExtended markin gwhic happear son th e
sidewall of th etire. You will fin dthis markin g
next to th etire siz edesignation ,th eload-bear -
ing capacit yand th espee dindex (
Ypage 348).
MOExtended tires may only be used in conjunc -
tion wit han active tire pressur eloss warning
system or wit han active tire pressur emonitor.
If apressure loss warning messag eappears
in th emultifunction display:
Robserv eth einstruction sin th edisplay mes -
sage s (Ypage 248)
Rcheck th etire for damag e
Rif driving on,observ eth efollowin gnote s
The driving distanc epossible in run-flat mod eis
approximately 50 mile s(80 km) when th evehi-
cle is partially laden .When th evehicl eis fully
laden it is approximately 19 mile s(30 km).
In addition to th evehicl eload, th edriving dis-
tance possible depend supon :
Rvehicl espee d
Rroad condition
Routside temperature
The driving distanc epossible in run-flat mod e
may be reduce dby extreme driv ing condi
tion
s
or maneuvers, or it can be increased throug h a
moderat estyle of driving .
The driving distanc epossible in run-flat mod eis
counted from th emomen tth etire pressur eloss
warning appear sin th emultifunction display.
You must no texcee d amaximum permissible
spee dof 50 mph (80 km/h).
318Flat tire
Breakdown assistance

RMake sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts.
RNever place metal objects or tools on a bat-tery.
RIt is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
RWhen jump-starting, make sure that the
battery poles with identical polarity are
connected.
RIt is particularly important to observe the
described order when connecting and dis-
connecting the jumper cables.
RNever connect or disconnect the battery
terminals while the engine is running.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-
tion.
All vehicles:
HEnvironmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately and recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
!Have the battery regularly checked at a
qualified specialist workshop. Comply with the service intervals in the Main-
tenance Booklet, or contact a qualified spe-
cialist workshop for more information.
!Always have work on batteries carried out at
a qualified specialist workshop.
Should it, in exceptional circumstances, be
absolutely necessary to disconnect the 12-
volt battery yourself, please observe the fol-
lowing:
RSecure the vehicle to prevent it from rolling
away.
RSwitch off the ignition.
RDisconnect the negative terminal first and
then the positive terminal.
The transmission is locked in position j
after disconnecting the battery.
After the work has been done, install the bat- tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
Electrolyte or battery acid is corro-
sive. Avoid contact with skin, eyes or
clothing. Wear suitable protective
clothing, especially gloves, apron
and faceguard. Immediately rinse
electrolyte or acid splashes off with
clean water. Contact a physician if
necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Battery (vehicle)323
Breakdown assistance
Z

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 must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle.
In this case, have the battery disconnected at a
qualified specialist workshop. You can also
charge the battery with a charger recommended
by Mercedes-Benz. Contact a qualified special-
ist workshop for further information.
Have the battery charge state checked more
frequently 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 for a long
period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrical consumers.
The vehicle will then use very little energy, thus
conserving 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 vehicles except vehicles with a lithium-
ion battery:
!Only use battery chargers with a maximum
charging voltage of 14.8 V.
GWARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery.
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do
not inhale any battery gases. Do not lean over
the battery. Keep children away from batter-
ies. Wash away battery acid immediately with plenty of clean water and seek medical atten-
tion.
GWARNING
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-
starting connection point.
The jump-starting connection point is in the
engine compartment (
Ypage 325).
XOpen the hood.
XConnect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (
Ypage 325).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it
is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the
battery charger's operating instructions before
charging the battery.
All vehicles except vehicles with a lithium-
ion battery: if the warning and indicator lamps
on the instrument cluster do not light up at low
temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may
neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery
may be shorter. The starting characteristics can
be impaired, particularly at low temperatures.
Have the thawed-out battery checked at a quali-
fied specialist workshop.
Vehicles with a lithium-ion battery: at low
temperatures, do not charge a battery which has
been removed using a battery charger. Allow the
324Battery (vehicle)
Breakdown assistance

battery to warm up gently first, if necessary.
Otherwise, the service life can be shortened andthe starting characteristics impaired, especially
at low temperatures.
Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point.
All vehicles except vehicles with a lithium-ion battery:
GWARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention.
GWARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery.
GWARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
RMake sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
RNever place metal objects or tools on a battery.
RIt is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
RWhen jump-starting, make sure that the battery poles with identical polarity are connected.
RIt is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
RNever connect or disconnect the battery terminals while the engine is running.
GWARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting 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.
If the warning and indicator lamps do not light up on the instrument cluster when temperatures are low, it is probably because the discharged battery has frozen. In this case, you may neither charge
the battery nor jump-start the vehicle. The service life of a thawed-out battery may be shorter. The
starting characteristics can be impaired, particularly at low temperatures. Have the thawed battery
checked at a qualified specialist workshop.
All vehicles:
Jump-starting325
Breakdown assistance
Z