2019 MERCEDES-BENZ GLS SUV engine overheat

&
WARNING Risk of accident when switch‐
ing off the ignition when driving
If yo u swit choff the ignition while driving,
saf ety functions are restricted or no longer
av ailable. This may af fect the po werst eering
sy stem and the brake forc e boosting, for
ex ample.
Yo u will then need touse considerably more
fo rc eto steer and brake. #
Do not switch off the ignition while driv‐
ing. &
DANG ER Risk of fata l injuries due to
ex haust gases
Combustion engines emit poisonous exhaust
ga ses such as carbon monoxide. Inhaling
th ese exhaust gases is hazardous tohealth
and can lead topoisoning. #
Never lea vethe engine running in an
enclosed space wi thout suf ficient venti‐
lation. &
WARNING Risk of skidding and of an
accident due toshifting down on slippery
ro ad sur faces
If yo u shift down on slippery road sur faces to
inc rease the engine braking ef fect, the drive
wheels may lose traction. #
Do not shift down on slippery road sur‐
fa ces toinc rease the engine braking
ef fect. &
DANG ER Risk of fata l injuries due topoi‐
sonous exhaust gases
If th eta ilpipe is bloc ked or suf ficient ventila‐
tion is not possible, poisonous exhaust gases
such as carbon monoxide may enter theve hi‐
cle. This is the case, forex ample, if theve hi‐
cle is stuck in sn ow. #
When the engine or thest ationary
heater are running, keep theta ilpipe
and the area around theve hicle clear of
sno w. #
Open a window on the side of theve hi‐
cle facing the wind toensure an ade‐
qu ate supply of fresh air. &
WARNING Risk of accident due tothe
brake sy stem overheating
If yo u lea veyour foot on the brake pedal
when driving, the brake sy stem may over‐
heat.
This increases the braking dis tance and the
brake sy stem may evenfa il. #
Never use the brake pedal as a foot re st. #
Do not depress the brake pedal and the
accelerator pedal at the same time
while driving. *
NO
TECausing wearto the brake linings
by permanently depressing the brake
pedal #
Do not permanently depress the brake
pedal while driving. 194
Driving and pa rking

&
WARNING Risk offire from fuel mixture
Ve hicles with a diesel engine:
If yo u mix diesel fuel with petrol, theflash
point of the fuel mixture is lo werth an that of
pure diesel fuel.
While the engine is running, component
pa rts in theex haust sy stem may overheat
without warning. #
Neverre fuel using petrol. #
Never mix petrol with diesel fuel. *
NO
TEDama gecaused bythe wrong fuel Ve
hicles with a petrol engine:
Even small amounts of the wrong fuel could
re sult in damage tothe fuel sy stem, the
engine and the emission control sy stem. #
Only refuel using unleaded, sulphu r-free
fuel that con form sto European EN 228,
or an equi valent specification. #
The RONrequ irement is located in the
fuel filler flap. Fu
el of this specification may con tain up to
10 %ethanol. Your vehicle is suitable for use
with E10 fuel.
Ne verre fuel using any of thefo llowing fuels:
R diesel
R regular petrol with an octane number
lo we rth an 91 RON
R petrol with more than 10%ethanol byvol‐
ume, e.g. E15, E30, E85, E100
R petrol with more than 3% me thanol by
vo lume, e.g. M15, M30
R petrol with additives con taining me tal
If yo u acciden tally refuel with the wrong fuel: #
Do not switch the ignition on. #
Consult a qualified specialist workshop. *
NO
TEDama gecaused bythe wrong fuel Ve
hicles with a diesel engine:
Even small amounts of the wrong fuel could
re sult in damage tothe fuel sy stem, the
engine and the emission control sy stem. #
Only refuel using sulphu r-free diesel
fuel that con form sto European stand‐
ard EN 590, or an equivalent specifica‐
tion.
In countries without sulphur-f ree diesel
fuel, refuel using only lo w-sulphur diesel
fuel with a sulphur content less than
50 ppm.
Ne verre fuel using any of thefo llowing fuels:
R petrol
R marine diesel
R heating oil
R pure bio-diesel fuel or vege table oil
R paraf fin or kerosene
If yo u accidentally refuel with the wrong fuel: #
Do not switch the ignition on. #
Consult a qualified specialist workshop. Driving and parking
213

speed abo
ve20 km/h up tothe maximum speed
or up tothe set winter tyre limit. The maximum
speed is reduced when driving in LOWRANGE
off-road gear (/ page210).
If yo ufa ilto adapt your driving style, cruise con‐
trol can neither reduce therisk of an accident
nor override the la wsof ph ysics. It cannot take
into account road, weather or traf fic conditions.
Cruise control is only an aid. You are responsible
fo r maintaining a safe dis tance totheve hicle in
front, forve hicle speed, for braking in good time
and forst ay ing in lane.
Displa yson the multifunction display
The status of cruise control and thestored
speed are shown in the multifunction displa y. 1
Cruise cont rol is selec ted
2 Speed is sa ved, cruise control is deactivated
3 Speed is sa ved, cruise control is activated
% The segments extending from the cur rent
st ored speed tothe end of the scale, or to
th e set winter tyre limit, light up in the
speedome ter.
Sy stem limits
Cruise control may be unable tomaintain the
st ored speed on uphill gradients. The stored
speed is resumed when the gradient evens out.
Change into a lo werge ar in good time on long
and steep downhill gradients. Take particular no
te ofthis when driving a laden vehicle. By
doing so, you will make use of the engine's brak‐
ing ef fect. This relie vesth e load on the brake
sy stem and pr events the brakes from overheat‐
ing and wearing tooqu ickl y.
Do not use cruise control in thefo llowing situa‐
tions:
R In traf fic situations whi chrequ ire frequent
ch anges of speed, e.g. in heavy traf fic, on
winding roads.
R On slippe ryroads. Accelerating can cause
th e drive wheels tolose traction and the
ve hicle could then skid.
R Ifyo u are driving when visibility is poor.
Fu nction of the limiter
The limiter restricts the speed of theve hicle. To
re duce the speed tothe set speed, the limiter
applies the brakes automaticall y.
Yo u can limit the speed as follo ws:
R Variable: for speed restrictions, e.g. in built-
up areas.
R Perm anen t:for long-term speed restrictions,
e.g. when driving in winter tyre mode. 242
Driving and pa rking

Instrument display
overview &
WARNING Risk of accident due toan
instrument display malfunction
If th e Instrument Display has failed or mal‐
functioned, you may not recognise function
re strictions applying tosaf etyre leva nt sys‐
te ms.
The operating saf ety of your vehicle may be
impaired. #
Drive on carefull y. #
Have theve hicle checked immediately
at a qualified specialist workshop. If
th e operating saf ety of your vehicle is
impaired, park theve hicle safely as soon as pos‐
sible. Contact a qualified specialist workshop. Instrument display in
the widescreen cockpit 1
Speedome ter (e xamp le)
2 Multifunction display
3 Rev counter (e xample)
4 Coolant temp erature display
5 Fuel le vel and fuel filler flap location indica‐
tor
% In addition tothe multifunction display 2,
fur ther conte nt can be shown on displ ays1
and 3(/ page 322).
The segments on the speedome ter1 indica te
th e sy stem status forth efo llowing:
R Cruise control(/ page241) R
Limi ter (/ page242)
R Active Dis tance Assi st
DISTRONIC( /page 247)
* NO
TEEngine dama gedue toexc essively
high engine speeds The engine will be damaged if
you drive with
th e engine in theov errevving range. #
Do not drive wi th the engine in theove r‐
re vving range. The fuel supply will be inter
rupted toprotect the
engine when there d mark on there v counter
(o ve rrev ving range) is reached.
During no rmal operating conditions, the coolant
te mp erature display may rise to120 °C. &
WARNING Danger of bu rns when open‐
ing the bonn et
If yo u open the engine bonn etwhen the
engine has overheated or during a fire inthe
engine compartment, you could come into
contact with hot gases or other escaping
operating fluids. In
stru ment Display and on-board computer 319

fi
ed based on the actual operating conditions
and/or loads.
Examples of arduous operating conditions:
R regular city driving with frequent intermedi‐
ate stops
R mainly short-dis tance driving
R frequent operation in mountainous terrain or
on poor road sur faces
R when the engine is of ten le ftidling for long
periods
R operation in particula rly dusty conditions
and/or if air-recirculation mode is frequently
used
In these or similar operating conditions, ha vethe
interior air filter, engine air cleaner, engine oil
and oil filter etc. changed more frequent ly. The
ty re s must be checked more frequently if the
ve hicle is operated under increased loads. Fur‐
th er information can be obtained at a qualified
specialist workshop. Battery disconnection periods
The ASS
YST PLUS se rvice inter val display
can only calculate the service due da tewhen
th e bat tery is connected. #
Notedown the service due date displa yed on
th e instrument display before disconnecting
th e battery (/ page 531). Engine compartment
Opening/closing
the bonnet &
WARNING Risk of accident due todriv‐
ing with the engine bonn etunlo cked
An unloc ked engine bonn etmay open up
when theve hicle is in motion and block your
vie w. #
Never unlock the engine bonn etwhen
driving. #
Before every trip, ensure that the
engine bonn etis loc ked. &
WARNING Risk of accident and inju ry
when opening and closing the engine
bonn et
When opening or closing the engine bonn et,
it may suddenly drop into the end position.
There is a risk of injury for an yone in the
engine bonn et's range of mo vement. #
Only open or close the engine bonn et
when there are no persons in the
engine bonn et's range of mo vement. &
WARNING Danger of bu rns when open‐
ing the bonn et
If yo u open the engine bonn etwhen the
engine has overheated or during a fire inthe
engine compartment, you could come into
contact with hot gases or other escaping
operating fluids. #
Before opening the bonn et, allow the
engine tocool down. 532
Maintenance and care

#
Slowly turn the cap half a turn toallow
pressure toescape. #
Park theve hicle on a le vel sur face. #
Check the coolant temp erature display in the
instrument clus ter.
The coolant temp erature must be below
70 °C. #
Slowly turn cap 1anti-clockwise torelie ve
ov erpressure. #
Continue turning cap 1anti-clockwise and
re mo veit.
The coolant le vel is cor rect:
R ifth e engine is cold, up tomar ker bar 2.
R ifth e engine is warm, up to1.5 cm over
mar ker bar 2. #
If necessar y,top up with coolant that has
been appr ovedby Mercedes-Benz.
R Further information on coolant (/ page 604) To
pping up the windsc reen washer sy stem &
WARNING Danger of bu rns from hot
component parts in the engine compart‐
ment
Cer tain component parts in the engine com‐
partment may be very hot, e.g. the engine,
th era diator and parts of theex haust sy stem. #
Let the engine cool down and only
to uch the component parts described
below: &
WARNING Danger of bu rns when open‐
ing the bonn et
If yo u open the engine bonn etwhen the
engine has overheated or during a fire inthe
engine compartment, you could come into
contact with hot gases or other escaping
operating fluids. #
Before opening the bonn et, allow the
engine tocool down. #
Intheeve nt of a fire inthe engine com‐
partment, keep the engine bonn et
closed and call thefire service. &
WARNING ‑ Risk of fire and injury due to
windscreen washer concentrate
Wi ndsc reen washer concentrate is highly
fl ammable. It could ignite if it comes into
con tact wi thhot engine component parts or
th eex haust sy stem. Maintenance and care
537

The
recommended octane number foryo ur vehi‐
cle can also be found on the instruction label in
th e fuel filler flap (/ page212).
As a temp orary measure, if there commended
fuel is not available, you may also use regular
unleaded petrol with at least 91RON. This may
re duce engine output and increase fuel con‐
sum ption.
Ne verre fuel using petrol with an even lo wer
RO N.
Fu rther information on fuel can be obtained at a
fi lling station or a qualified specialist workshop.
Information on additives in petrol
Obser vethe no tes on operating fluids
(/ page 597).
* NO
TEDama gefrom use of unsuitable
additives Even small amounts of
the wrong additive
may lead tomalfunctions occur ring. #
Only add cleaning additives recommen‐
ded byMercedes-Benz tothe fuel. Mercedes-Benz
recommends that you use fuel
brands that ha veadditives.
In some countries, the fuel available may not
ha ve suf ficient additives. Residue could build up
in the fuel injection sy stem as a result. In this
case, in consultation with a Mercedes-Benz
service centre, the fuel may be mixed with the
cleaning additive recommended byMercedes-
Benz. Be sure toobser vethe no tes and mixing
ra tios speci fied on the conta iner.
Information on fuel grades forve hicles with
a diesel engine
Gene ral no tes
Obser vethe no tes on operating fluids
(/ page 597). &
WARNING Risk offire from fuel mixture
If yo u mix diesel fuel with petrol, theflash
point of the fuel mixture is lo werth an that of
pure diesel fuel.
While the engine is running, component
pa rts in theex haust sy stem may overheat
without warning. #
Neverre fuel using petrol in diesel
engines. #
Never mix petrol with diesel fuel. *
NO
TEDama gecaused bythe wrong fuel Even small amounts of
the wrong fuel could
re sult in damage tothe fuel sy stem, the
engine and the emission control sy stem. #
Only refuel using sulphu r-free diesel
fuel that con form sto European stand‐
ard EN 590, or an equivalent specifica‐
tion.
In countries without sulphur-f ree diesel
fuel, refuel using only lo w-sulphur diesel
fuel with a sulphur content less than
50 ppm.
Ne verre fuel with one of thefo llowing fuels:
R petrol
R marine diesel
R heating oil
R pure bio-diesel fuel or vege table oil 600
Tech nical da ta

&
WARNING Risk of an accident due to
va pour poc kets form ing in the brake sys‐
tem
The brake fluid constantly absorbs moisture
from the air. This lo wersthe boiling point of
th e brake fluid. If the boiling point is too lo w,
va pour poc kets may form inthe brake sys‐
te m when the brakes are applied hard.
This impairs the braking ef fect. #
Have the brake fluid rene we d at the
specified inter vals. Ha
ve the brake fluid regularly replaced at a
qu alified specialist workshop.
Only use brake fluid appr ovedby Mercedes-Benz
according toMB-F reigabe or MB-Appr oval 33 1.0.
Yo u can obtain fur ther information on brake fluid
in thefo llowing places:
R inthe Mercedes-Benz Specifications for
Operating Fluids
- at http://be vo.mercedes-benz.com
- inthe Mercedes-Benz BeVo App
R at a qualified specialist workshop Coolant
Note
s on coolant
Obser vethe no tes on operating fluids
(/ page 597). &
WARNING Risk offire ‑ and inju ryfrom
antifreeze
If antifreeze comes into contact with hot
component parts in the engine compart‐
ment, it may ignite. #
Allow the engine tocool down before
yo uto p up the antif reeze. #
Make sure that no antifreeze spills out
next tothefiller opening. #
Thoroughly clean the antif reeze from
component parts before starting the
ve hicle. *
NO
TEDama gecaused byincor rect cool‐
ant #
Only add coolant that has been pre‐
mixed with therequ ired antifreeze pro‐
te ction.
Information on coolant is available at thefo l‐
lowing locations:
R inthe Mercedes-Benz Specification for
Operating Fluids 310.1
- at http://be vo.mercedes-benz.com
- inthe Mercedes-Benz BeVo app
R at a qualified specialist workshop *
NO
TEOverheating at high outside tem‐
peratures If an inapp
ropriate coolant is used, the
engine cooling sy stem is not suf ficiently pro‐
te cted against overheating and cor rosion at
high outside temp eratures. #
Alw ays use coolant appr ovedby
Mercedes-Benz. 604
Tech nical da ta