engine overheat MERCEDES-BENZ GLC 2017 Owners Manual

clean water. Seek medical assistance with-
out delay. R
If fuel is swallowed, seek medical assis-
tance without delay. Do not induce vomit-
ing. R
Immediately change out of clothing which
has come into contact with fuel.
G WARNING
Electrostatic buildup can create sparks and
ignite fuel vapors. There is a risk of fire and
explosion.
Always touch the vehicle body before opening
the fuel filler flap or touching the fuel pump
nozzle. Any existing electrostatic buildup is
thereby discharged.
Do not get into the vehicle again during the refu-
eling process. otherwise electrostatic charge
could build up again.
G WARNING
Vehicles with a diesel engine:
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.
! Do not use diesel to refuel vehicles with a
gasoline engine. Do not switch on the ignition
if you accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel system.
Even small amounts of the wrong fuel could
result in damage to the fuel system and the
engine. Notify a qualified specialist workshop
and have the fuel tank and fuel lines drained
completely.
! Do not use gasoline to refuel vehicles with a
diesel engine. Do not switch on the ignition if
you accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel system.
Even small amounts of the wrong fuel could
result in damage to the fuel system and the
engine. The repair costs are high. Notify a
qualified specialist workshop and have the
fuel tank and fuel lines drained completely. ! Overfilling the fuel tank could damage the
fuel system.
! Take care not to spill any fuel on painted
surfaces. You could otherwise damage the
paintwork.
! Use a filter when adding fuel from a fuel can.
The fuel lines and/or the fuel injection system
could otherwise be blocked by particles from
the fuel can.
If you overfill the fuel tank, fuel could spray out
when the fuel pump nozzle is removed.
For further information on fuel and fuel quality
( Y
page 364).
Refueling
General information Pay attention to the important safety notes
( Y
page 148).
If you unlock/lock the vehicle from the outside,
the fuel filler flap also unlocks/locks.
The position of the fuel filler cap is displayed in
the instrument cluster

When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage
is not covered by the Mercedes-Benz war-
ranty.
Heavy and light loads
G WARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This
increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive
on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance. R
In order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions. R
Carefully depress the brake pedal and the
beginning and end of a journey. R
Maintain a greater distance to the vehicle
ahead.
Servicing the brakes
! The brake fluid level may be too low, if: R
if the red brake warning lamp lights up in
the instrument cluster and R
you hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
! Vehicles with 4MATIC: function or per-
formance tests may only be carried out on a 2-
axle dynamometer. If you wish to operate the
vehicle on such a dynamometer, please con-
sult a qualified specialist workshop in
advance. You could otherwise damage the
drive train or the brake system.
! Vehicles with 4MATIC: the ESP ®
system
operates automatically. If the electric parking
brake is tested on a brake dynamometer, the
engine and ignition must be switched off: turn
the SmartKey in the ignition lock to position

braking maneuvers. Do not use the cruise con-
trol or DISTRONIC PLUS.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed: X
Shift the transmission to position \\ .
The outside temperature indicator is not
designed to serve as an ice-warning device and
is therefore unsuitable for that purpose.
Changes in the outside temperature are dis-
played after a short delay.
Indicated temperatures just above the freezing
point do not guarantee that the road surface is
free of ice. The road may still be icy, especially in
wooded areas or on bridges. The vehicle could
skid if you fail to adapt your driving style. Always
adapt your driving style and drive at a speed to
suit the prevailing weather conditions.
You should pay special attention to road condi-
tions when temperatures are around freezing
point.
For more information on driving with snow
chains, see ( Y
page 338).
For more information on driving with summer
tires, see ( Y
page 338).
Observe the notes in the "Winter operation" sec-
tion ( Y
page 338).
Driving systems
Mercedes-Benz Intelligent Drive Mercedes-Benz Intelligent Drive stands for inno-
vative driver assistance and safety systems
which enhance comfort and support the driver in
critical situations. With these intelligent co-ordi-
nated systems Mercedes-Benz has set a mile-
stone on the path towards autonomous driving.
Mercedes-Benz Intelligent Drive embraces all
elements of active and passive safety in one well
thought out system – for the safety of the vehi-
cle occupants and that of other road users.
Further information on driving safety systems
( Y
page 64).
Cruise control
General notes
Cruise control maintains a constant road speed
for you. It brakes automatically in order to avoid
exceeding the set speed. Change into a lower gear in good time on long and steep downhill
gradients. This is especially important if the
vehicle is laden or towing a trailer. By doing so,
you will make use of the braking effect of the
engine. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a steady
speed for a prolonged period. You can store any
road speed above 20 mph (30 km/h).
Important safety notes Cruise control can neither reduce the risk of an
accident if you fail to adapt your driving style nor
override the laws of physics. Cruise control can-
not take into account the road, traffic and
weather conditions. Cruise control is only an
aid. You are responsible for maintaining a safe
distance to the vehicle in front, for vehicle
speed, for braking in good time and for staying in
lane.
Do not use cruise control: R
in road and traffic conditions which do not
allow you to maintain a constant speed, e.g. in
heavy traffic or on winding roads R
on slippery road surfaces. Braking or accel-
erating could cause the drive wheels to lose
traction and the vehicle could then skid R
when there is poor visibility, e.g. due to fog,
heavy rain or snow
If there is a change of drivers, advise the new
driver of the speed stored.
i The speed indicated in the speedometer
may differ slightly from the speed stored.
Cruise control lever
C
Activates or increases speed
D
Activates or reduces speed162
Driving systems
Driving and parking

DISTRONI C PLUS
General notes DISTRONIC PLU S regulates th e speed and auto-
matically helps you maintain th e distanc e from
th e vehicle detecte d in front. Vehicles are detec -
te d wit h th e aid of th e radar sensor system.
DISTRONIC PLU S brake s automatically so that
th e set speed is no t exceeded.
Change into a lowe r gear in goo d time on lon g
and steep downhill gradients. Thi s is especially
important if th e vehicle is laden. By doin g so, you
will mak e use of th e braking effect of th e engine.
Thi s relieves th e load on th e brake syste m and
prevents th e brake s from overheatin g and wear -
in g to o quickly.
If DISTRONIC PLU S detects that there is a ris k of
a collision , you will be warned visually and
acoustically. DISTRONIC PLU S canno t preven t a
collision without your intervention . An intermit -
tent warnin g tone will then soun d and th e dis -
tanc e warnin g lamp will ligh t up in th e instru-
men t cluster. Brak e immediately in order to
increase th e distanc e to th e vehicle in fron t or
take evasiv e action provided it is saf e to do so.
DISTRONIC PLU S operates in th e speed range
between 0 mph (0 km/ h) an d 120 mph
(200 km/h).
Do not use DISTRONIC PLUS whil e driving on
roa ds with steep gradients.
As DISTRONIC PLUS transmits radar waves, it
can resemble the radar detectors of the respon-
sible authorities. You can refer to the relevant
chapter in the Operator's Manual if questions
are asked about this.
i USA only: This device has been approved by
the FCC as a "Vehicular Radar System". The
radar sensor is intended for use in an auto-
motive radar system only. Removal, tamper-
ing, or altering of the device will void any war-
ranties, and is not permitted by the FCC. Do
not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
i Canada only: This device complies with
RSS-210 of Industry Canada. Operation is
subject to the following two conditions:
1. This device may not cause interference,
and 2. This device must accept any interference
received, including interference that may
cause undesired operation of the device.
Removal, tampering, or altering of the device
will void any warranties, and is not permitted.
Do not tamper with, alter, or use in any non-
approved way.
Any unauthorized modification to this device
could void the user's authority to operate the
equipment.
Important safety notes
G WARNING
DISTRONIC PLUS does not react to: R
people or animals R
stationary obstacles on the road, e.g. stop-
ped or parked vehicles R
oncoming and crossing traffic
As a result, DISTRONIC PLUS may neither give
warnings nor intervene in such situations.
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
G WARNING
DISTRONIC PLUS cannot always clearly iden-
tify other road users and complex traffic sit-
uations.
In such cases, DISTRONIC PLUS may: R
give an unnecessary warning and then
brake the vehicle R
neither give a warning nor intervene R
accelerate or brake unexpectedly
There is a risk of an accident.
Continue to drive carefully and be ready to
brake, in particular when warned to do so by
DISTRONIC PLUS.
G WARNING
DISTRONIC PLUS brakes your vehicle with up
to 50% of the maximum possible deceleration.
If this braking force is insufficient, DISTRONIC
PLUS warns you visually and audibly. There is
a risk of an accident.164
Driving systems
Driving and parking

which the maximum permissible speed for vehi-
cle/trailer combinations is above 60 mph
(100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison to
when driving without a trailer and it will con-
sume more fuel.
Shift to a lower gear on long and steep downhill
gradients.
This also applies to: R
activated DISTRONIC PLUS R
activated cruise control
This will use the braking effect of the engine, so
that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem and prevents the brakes from overheating
and wearing too quickly. If you need additional
braking, depress the brake pedal repeatedly
rather than continuously.
Driving tips If the trailer swings from side to side: X
Do not accelerate. X
Do not counter-steer. X
Brake if necessary. R
Maintain a greater distance from the vehicle
in front than when driving without a trailer. R
Avoid braking abruptly. If possible, brake gen-
tly at first to allow the trailer to run on. Then,
increase the braking force rapidly. R
The values given for gradient-climbing capa-
bilities from a standstill refer to sea level.
When driving in mountainous areas, note that
the power output of the engine and, conse-
quently, the vehicle's gradient-climbing capa-
bility, decreases with increasing altitude.
Installing the ball coupling
G WARNING
If the ball coupling is not correctly installed
and secured, it could come loose while driving
and endanger other road users. There is a risk
of an accident and injury.
Install and secure the ball coupling as descri-
bed in the ball coupling manufacturer's instal-
lation instructions. Make sure that the ball coupling is correctly installed and secured
before every journey.
G WARNING
If the ball coupling is not installed and secured
correctly the trailer may come loose. There is
a risk of an accident.
Install and secure the ball coupling as descri-
bed in the ball coupling installation instruc-
tions. Make sure that the ball coupling is
installed and secured correctly before every
journey.
X
Pull protective cap C in the direction of the
arrow, out of the ball coupling recess. X
Stow protective cap C so that it cannot be
thrown around. X
Observe the manufacturer's installation
instructions.
Observe the loading guidelines ( Y
page 278)
and the safety notes regarding stowage
spaces ( Y
page 278).
Coupling up a trailer
! Do not connect the trailer's brake system (if
featured) to the hydraulic brake system of the
towing vehicle, as the latter is equipped with
an anti-lock brake system. Doing so will result
in a loss of function of the brake systems of
both the vehicle and the trailer. X
Apply the vehicle's electric parking brake
manually. X
Start the engine. X
Shift the transmission to position ] .X
Vehicles with AIR BODY CONTROL: select
the Comfort drive program.204
Towing a trailer
Driving and parking

Tachometer
! Do not drive in the overrevving range, as this
could damage the engine.
The red band in the tachometer indicates the
engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached.
Outside temperature display You should pay special attention to road condi-
tions when temperatures are around freezing
point.
Bear in mind that the outside temperature dis-
play indicates the temperature measured and
does not record the road temperature.
The outside temperature display is in the multi-
function display ( Y
page 210).
Changes in the outside temperature are dis-
played after a short delay.
Coolant temperature gauge
G WARNING
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.
! A display message is shown if the coolant
temperature is too high.
If the coolant temperature is over 248 ‡
(120 †), do not continue driving. The engine
will otherwise be damaged.
The coolant temperature gauge is in the lower
section of the tachometer ( Y
page 36).
Under normal operating conditions and with the
specified coolant level, the coolant temperature
may rise to 248 ‡ (120 †). Operating the on-board computer
C
Multifunction display D
Right control panel

Display messages
Possible causes/consequences and P Solutions
Servic e Required Do
Not Shift Gears
Visit Dealer You canno t chang e th e transmission position due to a malfunction .
A warning tone also sounds.
If transmission position [ is selected:X
Drive to a qualified specialist workshop without shifting th e trans -
mission from position [ .
If transmission position ^ , \\ or ] is selected:X
Secur e th e vehicl e against rollin g away ( Y
page 154).X
Notify a qualified specialist workshop or breakdown service.
Reversing Not Possi‐
ble Servic e Required You canno t shift int o transmission position ^ due to a malfunction .
The transmission position s ] , \\ or [ continu e to be available.
A warning tone also sounds. X
Visit a qualified specialist workshop .
Transmission Mal ‐
function Sto p A malfunction has occurred in th e mechanical transmission compo -
nents.
A warning tone also sounds. The transmission automatically shift s to
position \\ . X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Shift th e transmission to position ] .X
Secur e th e vehicl e against rollin g away ( Y
page 154).X
Notify a qualified specialist workshop or breakdown service.
Sto p Vehicl e Leave
Engine Runnin g Wai t
Transmission Cool‐
ing The transmission has overheated. Pullin g away can be temporarily
impaire d or no t possible.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions. Do no t continu e drivin g
under any circumstances. X
Leav e th e engin e running.X
Wait until th e display message disappear s before pullin g away.
e The tailgat e is open .
G WARNIN G
Whe n th e engin e is running, exhaust gase s can ente r th e vehicl e inte-
rio r if th e tailgat e is open .
There is a ris k of poisoning .X
Clos e th e tailgate. Display messages 25 3
On-board computer and displays Z

Engine compartment
Hood
Important safety notes
G WARNING
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.
G WARNING
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.
G WARNING
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.
G WARNING
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: R
switch off the ignition R
never reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area R
remove jewelry and watches R
keep items of clothing and hair, for exam-
ple, away from moving parts
Opening the hood
G WARNING
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.
G WARNING
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.
X
Make sure that the windshield wipers are
turned off. X
Pull release lever C on the hood.
The hood is released.306
Engine compartment
Maintenance and care

X
Reac h int o th e gap, pull hoo d catch handle D
up and lift th e hood.
If you lift th e hoo d by approximately 15 in
(40 cm), th e hoo d is opened and held open
automatically by th e gas-filled strut .
Closing the hood X
Lowe r th e hoo d and let it fall from a height of
approximately 8 in (20 cm).X
Chec k that th e hoo d has engage d properly.
If th e hoo d can be raised slightly, it is no t
properly engaged. Open it again and close it
wit h a littl e mor e force .
Radiator Do no t cover up th e radiator, suc h as wit h a
thermal mat or insec t protection cover . Other -
wise, th e value s of th e European on-board diag-
nostics may be affected. Some of these read -
ing s are require d by law and mus t be accurat e at
all times .
Engine oil
Important safety notes
G WARNIN G
Certain component s in th e engin e compart-
ment, suc h as th e engine, radiato r and part s
of th e exhaust system, can become ver y hot .
Workin g in th e engin e compartmen t poses a
ris k of injury.
Wher e possible, let th e engin e cool down and
touch only th e component s describe d in th e
following. G WARNIN G
The engin e compartmen t contain s moving
components. Certain components, suc h as
th e radiato r fan , may continu e to run or start
again suddenly when th e ignition is off . There
is a ris k of injury.
If you need to do any wor k inside th e engin e
compartment: R
switch off th e ignition R
never reac h int o th e area wher e there is a
ris k of danger from moving components,
suc h as th e fan rotation area R
remove jewelr y and watches R
keep items of clothing and hair , for exam-
ple, away from moving part s
G WARNIN G
If engin e oil comes int o contact wit h hot com-
ponents in th e engin e compartment, it may
ignite. There is a ris k of fir e and injury.
Mak e sur e that engin e oil is no t spilled next to
th e filler neck . Let th e engin e cool down and
thoroughly clean th e engin e oil off th e com-
ponents before starting th e engine.
G WARNIN G
Opening th e hoo d when th e engin e is over-
heated or when there is a fir e in th e engin e
compartmen t could expos e you to hot gase s
or other servic e products . There is a ris k of
injury.
Let an overheate d engin e cool down before
opening th e hood. If there is a fir e in th e
engin e compartment, keep th e hoo d closed
and contact th e fir e department.
General notes
Dependin g on your driving style, th e vehicl e
consumes up to 0. 9 US qt (0. 8 l) of oil per
60 0 mile 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 compartment 307
Maintenance and care Z

Where possible, let the engine cool down and
touch only the components described in the
following.
G WARNING
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: R
switch off the ignition R
never reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area R
remove jewelry and watches R
keep items of clothing and hair, for exam-
ple, away from moving parts
G WARNING
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.
G WARNING
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) X
Park 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. X
Turn the SmartKey to position H in the igni-
tion lock ( Y
page 132).
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 in the
instrument cluster ( Y
page 36).
The coolant temperature must be below
158 ‡ (70 †). X
Turn the SmartKey to position Z in the igni-
tion lock ( Y
page 132).
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 C half a turn counter-clock-
wise and allow excess pressure to escape. X
Turn cap C further counter-clockwise and
remove it.
If the coolant is at the level of marker bar