2020 MERCEDES-BENZ GLS SUV engine overheat

&
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 injury 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 when theve hicle
becomes stuck in sn ow,fo rex ample. #
Keep theta ilpipe and the area around
th eve hicle free from snow when the
engine or thest ationary heater are run‐
ning. #
Open a window on the side of theve hi‐
cle facing away from the wind toensure
an adequate 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
TEEngine dama gedue toexcessively
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. *
NO
TECausing wearto the brake linings
by permanently depressing the brake
pedal #
Do not permanently depress the brake
pedal while driving. #
Touse braking ef fect of the engine,
shift toa lo werge ar in good time. *
NO
TEDama getothe driv etra in and
engine when pulling away #
Do not warm upthe engine while the
ve hicle is stationar y.Pull away immedi‐
atel y. #
Avoid high engine speeds and driving at
full thro ttle until the engine has reached
its operating temp erature. *
NO
TEDama getothe catalytic con verter
due tonon-combu sted fuel The engine is not
running smo othly and is
misfiring. Driving and parking
19 3

#
Ifyo u swallow fuel, seek medical atten‐
tion immediatel y.Do not induce vomit‐
ing. #
Change immediately out of clo thing that
has come into con tact wi thfuel. &
WARNING Risk offire and explosion due
to electros tatic charge
Electros taticch arge can igni tefuel vapour. #
Before you open the fuel filler cap or
ta ke hold of the pump nozzle, touch the
me tallic vehicle body. #
Toavo id creating ano ther electros tatic
ch arge , do not getinto theve hicle again
during there fuelling process. &
WARNING Risk offire from fuel mixture
Ve hicles with a diesel engine:
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
petrol that con form sto European
EN 228, or an equi valent specification.
Fu el of this specification may con tain up to
10 %ethanol. Your vehicle is suitable for use
with E10 fuel.
Ne verre fuel with one 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, E20, 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 ha veacciden tally refuelled with the
wrong fuel: #
do not swit ch 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. 212
Driving and pa rking

A
stored speed appears along with theh dis‐
pla y.
% 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 a short-term speed restriction,
e.g. in built-up areas
R Perm anen t:for a longer-term speed restric‐
tion, e.g. in winter tyre mode
Yo u can store any speed abo ve20 km/h up to
th e maximum design speed or up tothe set win‐
te r tyre limit. You can also per form settings
while theve hicle is stationary if theve hicle has
been star ted.
Obser vethe no tes on driving sy stems and your
re sponsibility; you may otherwise failto recog‐
nise dangers (/ page 224).
Mercedes‑AMG vehicles: the limiter is available
up toa maximum speed of 250 km/h. Displ
ays on the multifunction display
R È (grey):va riable limiter is selec ted but
not yet acti vated.
R È (green): variable limiter is activated.
A stored speed appears along with theÈ dis‐
pla y.The segments in the speedome ter light up,
up tothe cur rently stored speed.
When the driving speed is greater than the
st ored speed, theÈ display flashes.
Kickd own
If yo u depress the accelerator pedal be yond the
pressure point (kickdown), theva riable limiter
swit ches topassive mode. The Limiter pas-
sivemessage appears in the multifunction dis‐
pla y.
Af ter completion of kickdown, theva riable lim‐
iter is activated again in thefo llowing situations:
R Ifth eve hicle speed drops below thestored
speed.
R Ifth estored speed is called up.
R Ifyo ustore a new speed. 234
Driving and parking

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 357). Engine compartment
Opening and closing
the bonnet &
WARNING Risk of accident due todriv‐
ing with the bonn etunlo cked
The bonn etmay open and block your vie w. #
Neverre lease the 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 bonn et
The bonnet may suddenly drop into the end
position.
There is a risk of injury for an yone in the bon‐
net's range of mo vement. #
Open or close the bonn etonly when
th ere is nobody in the 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. #
Intheeve nt of a fire inthe engine com‐
partment, keep the engine bonn et
closed and call thefire service. 358
Maintenance and care

#
Thoroughly clean the antif reeze from
component parts before starting the
ve hicle. *
NO
TEDama gecaused byincor rect cool‐
ant #
Only use 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 https://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. #
Obser vethe instructions in the
Mercedes-Benz Specifications for Oper‐
ating Fluids 310.1. Ha
ve the coolant regularly replaced at a qualified
specialist workshop.
Proportion of antifreeze concentrate in the
engine cooling sy stem:
R a minimum of 50% (antifreeze pr otection
down toappr oximately -37°C)
R a maximum of 55% (antifreeze pr otection
down to-45°C) Note
s on windscreen washer fluid Obser
vethe no tes on operating fluids
(/ page 417). &
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. #
Make sure that no windsc reen washer
concentrate spills out next tothefiller
opening. *
NO
TEDama getotheex terior lighting
due tounsuitable windsc reen washer
fl uid Uns
uitable windsc reen washer fluids may
damage the plastic sur face of theex terior
lighting. #
Only use windscreen washer fluids
which are also suitable for use on plas‐
tic sur faces, e.g. MB SummerFit or MB
Wi nterFit. Te
ch nical da ta425

Display messages
Possible causes/consequences and M
MSolutions #
Add coolant (/ page 362). #
Have the engine cooling sy stem checked at a qualified specialist workshop.
ÿ
Coolant Stop vehicle
Switch engine off *T
he coolant is too hot. #
Stop theve hicle immediately in accordance with the traf fic conditions and switch off the engine. &
WARNING Danger of bu rns when opening 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 wi thhot gases or other escaping operating fluids. #
Before opening the bonn et, allow the engine tocool down. #
Intheeve nt of a fire inthe engine compartment, keep the engine bonn etclosed and call thefire service. #
Wait until the engine has cooled down. #
Make sure that the air supply tothera diator is not obstructed. #
Avoiding high loads on the engine, drive tothe nearest qualified specialist workshop. In doing so, ensure that
th e coolant temp erature display remains below 120°C.
ÿ *T
hefan mo tor is defective. #
Avoiding high loads on the engine, drive tothe nearest qualified specialist workshop. In doing so, ensure that
th e coolant temp erature display remains below 120 °C. Displ
aymessa ges and warning/indicator lamps 451

Display messages
Possible causes/consequences and M
MSolutions #
Consult a qualified specialist workshop.
Stop vehicle Leave engine
running Wait Transmission
cooling *T
he transmission is overheating. Pulling away may be temp orarily impaired or not possible. #
Stop theve hicle immediately in accordance with the traf fic conditions. Do not continue driving. #
Lea vethe engine running. #
Wait until the display message disappears before pulling away.
Auxiliary battery malfunc-
tion *T
he auxiliary batteryforth e transmission is no longer being charge d. #
Consult a qualified specialist workshop. #
Untilthen, alw ays select park position jmanually before you swit choff the engine. #
Before leaving theve hicle, apply the electric parking brake. Brakes
Display messages
Possible causes/consequences and M MSolutions
! Parking brake See Owner's
Manual *
The yellow ! indicator lamp is lit. The elect ric pa rking brake is malfunctioning.
To appl y: #
Switch the ignition off and switch it back on. #
Apply the electric parking brake manually (/ page 222).
If it is not possible toapply the electric parking brake: Display messages and
warning/indicator lamps 455

Engine
Wa
rning/indicator lamp
Possible causes/consequences and M
MSolutions
ÿ Coolant warning lamp (red) *T
he red coolant warning lamp is lit while the engine is running.
Po ssible causes:
R The temp erature sensor is malfunctioning
R The coolant le vel is too low
R The air supply tothera diator is obstructed
R The radiator fan is faulty
R The engine coolant pump is faulty
If th ere is an additional warning tone, the coolant temp erature has exceeded 120°C. &
WARNING Danger of bu rns when opening 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 wi thhot gases or other escaping operating fluids. #
Before opening the bonn et, allow the engine tocool down. #
Intheeve nt of a fire inthe engine compartment, keep the engine bonn etclosed and call thefire service. #
Stop theve hicle immediately in accordance with the traf fic conditions and switch off the engine. Do not continue
driving. #
Notethe messages on the multifunction displa y. Displ
aymessa ges and warning/indicator lamps 495