2017 MERCEDES-BENZ GLC COUPE engine overheat

Display messagesPossible causes/consequences andMSolutions
?
CoolantToo HotSto pVehicl eTur nEngine Off
The coolan tis to ohot .
A warning tone also sounds.
GWARNIN G
Do no tdrive when your engin eis overheated. This can caus esom e
fluids whic hmay hav eleaked int oth eengin ecompartmen tto catch
fire.
Steam from th eoverheate dengin ecan also caus eserious burn swhic h
can occur jus tby opening th ehood.
There is aris kof injury.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 149).
XWait until th eengin ehas cooled down .
XMakesur ethat th eair supply to th eengin eradiato ris no tblocked,
e.g. by snow, slus hor ice .
XDo no tstart th eengin eagain until th edisplay message goe sout and
th ecoolan ttemperature is belo w24 8 ‡ (120†). Otherwise ,th e
engin ecould be damaged.
XPay attention to th ecoolan ttemperature gauge .
If th etemperatur eincreases again:
XVisit aqualified specialist workshop immediately.
Under normal operating condition sand wit hth especified coolan t
level, th ecoolan ttemperature may ris eto 24 8 ‡(120†).
#
See Operator' sMan ‐ual
The battery is no tbein gcharged.
A warning tone also sounds.
Possibl ecauses are:
Radefective alternato r
Ratorn poly-V-belt
Ramalfunction in th eelectronics
!Do no tcontinu edriving. The engin ecould otherwise overheat.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 149).
XConsult aqualified specialist workshop .
236Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
ServiceRequiredDoNot Shift GearsVisit Dealer
You canno tchang eth etransmission position due to amalfunction .
A warning tone also sounds.
If transmission position his selected:
XDrive to aqualified specialist workshop without shifting th etrans -
mission from position h.
If transmission position k,iorj is selected:
XSecur eth evehicl eagainst rollin gaway (Ypage 149).
XNotify aqualified specialist workshop or breakdown service.
ReversingNotPossi‐bleServic eRequiredYou canno tshift int otransmission position kdue to amalfunction .
The transmission position sj, iorh continu eto be available.
A warning tone also sounds.
XVisit aqualified specialist workshop .
Transmission Mal‐function StopAmalfunction has occurred in th emechanical transmission compo -
nents.
A warning tone also sounds. The transmission automatically shift sto
position i.
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XShift th etransmission to position j.
XSecureth evehicl eagainst rollin gaway (Ypage 149).
XNotify aqualified specialist workshop or breakdown service.
Sto pVehicl eLeaveEngineRunnin gWaitTransmission Cool‐ing
The transmission has overheated. Pullin gaway can be temporarily
impaire dor no tpossible.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XLeav eth eengin erunning.
XWait until th edisplay message disappear sbefore pullin gaway.
AThe tailgat eis open .
GWARNIN G
Whe nth eengin eis running, exhaust gase scan ente rth evehicl einte-
rio rif th etailgat eis open .
There is aris kof poisoning .
XCloseth etailgate.
248Display messages
On-board computer and displays

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 149).
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 303).
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 is below 248 ‡
(120 †). 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 has exceeded 248 ‡(120 †). 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 149).
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 303).
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.
Warning and indicator lamps in the instrument cluster259
On-board computer and displays
Z

Engine compartment
Hood
Important safety notes
GWARNING
If the hood is unlatched, it may open up when the vehicle is in motion and block your view.
There is a risk of an accident.
Never unlatch the hood while driving. Before
every trip, ensure that the hood is locked.
GWARNING
When opening and closing the hood, it may
suddenly fall into the closed position. There is a risk of injury to persons within range of
movement of the hood.
Open and close the hood only when no one is
within its range of movement.
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.
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
Opening the hood
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.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by
the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood.
!Make sure that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield wip-
ers or the hood.
XMake sure that the windshield wipers are
turned off.
XPull release lever :on the hood.
The hood is released.
300Engine compartment
Maintenance and care

XReachint oth egap, pull hoo dcatch handle ;
up and lift th ehood.
If you lift th ehoo dby approximately 15 in
(40 cm), th ehoo dis opened and held open
automatically by th egas-filled strut .
Closing the hood
XLowerth ehoo dand let it fall from aheight of
approximately 8in (20 cm).
XChec kthat th ehoo dhas engage dproperly.
If th ehoo dcan be raised slightly, it is no t
properly engaged. Open it again and close it
wit h a littlemor eforce .
Radiator
Do no tcover up th eradiator, suc has wit h a
thermal mat or insec tprotection cover .Other -
wise, th evalue sof th eEuropean on-board diag-
nostics may be affected. Some of these read -
ing sare require dby law and mus tbe accurat eat
all times .
Engine oil
Important safety notes
GWARNIN G
Certain component sin th eengin ecompart-
ment, suc has th eengine, radiato rand part s
of th eexhaust system, can become ver yhot .
Workin gin th eengin ecompartmen tposes a
ris kof injury.
Wher epossible, let th eengin ecool down and
touch only th ecomponent sdescribe din th e
following.
GWARNIN G
The engin ecompartmen tcontain smoving
components. Certain components, suc has
th eradiato rfan ,may continu eto run or start
again suddenly when th eignition is off .There
is aris kof injury.
If you need to do any wor kinside th eengin e
compartment:
Rswitch off th eignition
Rnever reac hint oth earea wher ethere is a
ris kof danger from moving components,
suc has th efan rotation area
Rremove jewelr yand watches
Rkeep items of clothing and hair ,for exam-
ple, away from moving part s
GWARNING
If engin eoil comes int ocontact wit hhot com-
ponents in th eengin ecompartment, it may
ignite. There is aris kof fir eand injury.
Mak esur ethat engin eoil is no tspilled next to
th efiller neck .Let th eengin ecool down and
thoroughly clean th eengin eoil off th ecom-
ponents before starting th eengine.
GWARNIN G
Opening th ehoo dwhen th eengin eis over-
heated or when there is afir ein th eengin e
compartmen tcould expos eyou to hot gase s
or other servic eproducts .There is aris kof
injury.
Let an overheate dengin ecool down before
opening th ehood. If there is afir ein th e
engin ecompartment, keep th ehoo dclosed
and contact th efir edepartment.
General notes
Dependin gon your driving style, th evehicl e
consumes up to 0. 9US qt (0. 8l) of oil per
60 0mile s(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
in a different location.
Engine compartment301
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 127).
or
XPress the Start/Stop button twice on vehicles
with KEYLESS-GO or the KEYLESS-GO start
function (
Ypage 128).
XCheck the coolant temperature display in the
instrument cluster (Ypage 35).
The coolant temperature must be below
158 ‡ (70 †).
XTurn the SmartKey to position gin the igni-
tion lock (Ypage 127).
or
XPress the Start/Stop button once on vehicles with KEYLESS-GO or the KEYLESS-GO start
function (
Ypage 128).
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 362).
Engine compartment303
Maintenance and care
Z

If standard unleaded gasoline is unavailable
and you have to refuel with unleaded gasoline
of a lower grade, observe the following pre-
cautions:
ROnly fill the fuel tank to half full with regular unleaded gasoline and fill the rest with pre-
mium-grade unleaded gasoline as soon as
possible.
RDo not drive at the maximum speed.
RAvoid sudden acceleration and engine
speeds over 3,000 rpm.
You will usually find information about the fuel
quality on the pump. If you cannot find the label on the fuel pump, ask the gas station staff.
iFor further information, consult a qualified
specialist workshop or visit
http://www.mbusa.com (USA only).
As a temporary measure, if the recommended
fuel is not available, you may also use regular
unleaded gasoline with an octane rating of
87 AKI/91 RON. This may reduce engine per-
formance and increase fuel consumption. Avoid
driving at full throttle and sudden acceleration.
Never refuel using gasoline with a lower AKI.
Information on refueling (
Ypage 144).
Additives
!Operating the engine with fuel additives
added later can lead to engine failure. Do not
mix fuel additives with fuel. This does not
include additives for the removal and preven-
tion of residue buildup. gasoline must only be mixed with additives recommended by
Mercedes-Benz. Comply with the instructions
for use on the product label. More information
about recommended additives can be
obtained from any authorized Mercedes-Benz
Center.
Mercedes-Benz recommends that you use bran-
ded fuels that have additives.
The fuel quality available in some countries may
not be sufficient. Residue could build up in the
fuel injection system as a result. In such cases,
and in consultation with an authorized
Mercedes-Benz Center, the fuel may be mixed
with the cleaning additive recommended by
Mercedes-Benz. You must observe the notes
and mixing ratios specified on the container.
Diesel
Fuel grade
GWARNING
If you mix diesel fuel with gasoline, the flash
point is lower than that of pure diesel fuel.
When the engine is running, exhaust system
components could overheat without being
noticed. There is a risk of fire.
Never refuel with gasoline. Never mix gasoline with diesel fuel.
!Refuel only using diesel fuel that conforms
to European standard EN 590 or an equivalent
specification. Fuel that does not conform to
EN 590 can lead to increased wear and dam-
age the engine and exhaust system.
!Do not use the following:
Rmarine diesel
Rheating oil
Rbio-diesel
Rvegetable oil
Rgasoline
Rparaffin
Rkerosene
Do not mix such fuels with diesel fuel and do
not use any special additives. Otherwise,
engine damage may occur.
!In countries outside the EU, only use low-
sulfur Euro diesel with a sulfur content of
under 50 ppm. Otherwise, the emission con-
trol system could be damaged.
You will usually find information about the fuel
quality on the pump. If you cannot find the label
on the fuel pump, ask the gas station staff.
Information on refueling (
Ypage 144).
Low outside temperatures
iDiesel fuel with improved cold flow proper-
ties is available during the winter months.
Further information about fuel properties can
be obtained from oil companies, e.g. at gas
stations.
360Service products and filling capacities
Technical data

Gasoline enginesMB-Freigabe orMB-Approval
All models229.5, 229.6
Diesel enginesMB-Freigabe orMB-Approval
All models228.51, 229.31,229.51, 229.52
iMB approval is indicated on the oil contain-
ers.
Filling capacities
The following values refer to an oil change
including the oil filter.
ModelCapacity
GLC 300 d 4MATIC
Coupe6.3 US qt (6.0 l)
Allot her models6.9 US qt (6.5 l)
Additives
!Do not use any additives in the engine oil.
This could damage the engine.
Brake fluid
GWARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake
fluid is too low, vapor pockets may form in the
brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
When handling brake fluid, observe the impor-
tant safety notes on service products
(
Ypage 358).
The brake fluid change intervals can be found in
the Maintenance Booklet. Only use brake fluid approved by Mercedes-
Benz in accordance with MB-Freigabe or MB-
Approval 331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or
on the Internet at
http://bevo.mercedes-benz.co
m.
iHave the brake fluid regularly replaced at a
qualified specialist workshop in accordance
with the replacement intervals and the
replacement confirmed in the Maintenance
Booklet.
Coolant
Important safety notes
GWARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
!Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
Further information on coolants can be found
in the Mercedes-Benz Specifications for Ser-
vice Products, MB BeVo 310.1, e.g. on the
Internet at http://bevo.mercedes-benz.com.
Or contact a qualified specialist workshop.
!Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
iHave the coolant regularly replaced at a
qualified specialist workshop and the replace-
ment confirmed in the Maintenance Booklet.
Comply with the important safety notes for ser-
vice products when handling coolant
(
Ypage 358).
362Service products and filling capacities
Technical data