2020 MERCEDES-BENZ GLS SUV service

&
WARNING Risk ofexplosion during
ch arging process and starting assis tance
During thech arging process and starting
assis tance, the battery may release an explo‐
sive gas mixture. #
Avoid fire , naked flames, creating
spar ksand smoking. #
Make sure there is suf ficient ventila‐
tion. #
Do not lean over a batter y. &
WARNING Risk ofexplosion from a fro‐
zen battery
A dischar ged battery may freeze at temp era‐
tures slightly abo veor below freezing point.
During starting assis tance or battery charg‐
ing, bat tery gas can be released. #
Alw ays allow a battery tothaw before
ch arging it or per form ing starting assis‐
ta nce. If
th e indicator/warning lamps in the instrument
clus ter do not light up at low temp eratures, it is
ve ry likely that the dischar ged battery has fro‐
zen. In this case you may neither jump-s tart the
ve hicle nor charge the batter y.
The service life of a battery that has been
th awe d may be dramatically shor tened. The
st arting characteristics may be impaired, espe‐
cially at low temp eratures.
It is recommended that you ha veathaw ed bat‐
te ry checked at a qualified specialist workshop.
All vehicles
* NO
TEDama gecaused bynumerous or
ex tended attem ptsto start the engine Nume
rous or extended attem ptsto start the
engine may damage the catalytic con verter
due tonon-combu sted fuel. #
Avoid numerous and extended attem pts
to start the engine. Obser
vethefo llowing points during starting
assis tance and when charging the battery:
R Only use undamaged jump lead/charging
cables with a suf ficient cross-section and
insula tedte rm inal clamps.
R Non- insulated parts of thete rm inal clamps
must not come into con tact wi thother me tal
parts while the jump lead/charging cable is
connected tothe battery/jump-s tart connec‐
tion point.
R The jump lead/charging cable must not
come into contact wi thany parts which may
mo vewhen the engine is running.
R Alw ays make sure that nei ther you nor the
battery is elect rostatically charge d.
R Keep away from fire and naked flames.
R Do not lean overth e batter y.
Obser vethe additional following points when
ch arging the battery:
R Only use battery charge rs tested and
appr oved for Mercedes-Benz.
R Read the battery charge r's operating instruc‐
tions before charging the batter y. Breakdown assis
tance 383

#
First,re mo vethe jump lead/charging cable
from ear thpoint 3and the negative pole of
th e donor batter y,then from positive clamp
2 and the positive pole of the donor bat‐
te ry. Begin ea chtime wi th the conta cts on
yo ur ow nve hicle firs t. #
Afterre moving the jump lead/charging
cable, close co ver1 of positive clamp 2.
Fu rther information can be obtained at a quali‐
fi ed specialist workshop. Re
placing the 12V battery #
Obser vethe no tes on the12 V battery
(/ page 380).
Mercedes-Benz recommends that you ha vethe
12 V battery replaced at a qualified specialist
wo rkshop, e.g. at a Mercedes-Benz Service
Centre. Obser
vethefo llowing no tes if youwa ntto
re place the battery yourself:
R Alw aysre place a faulty bat tery with a battery
which meets the specific vehicle require‐
ments.
The vehicle is equipped with an AGMtech nol‐
ogy battery (Absorbent Glass Mat) or a li th‐
ium-ion batter y.Fu llve hicle functionality is
only guaranteed with an AGM battery or lith‐
ium-ion batter y.Fo r saf etyre asons,
Mercedes-Benz recommends that you on ly
use bat teries which ha vebeen tested and
appr ovedfo ryo ur vehicle byMercedes-Benz.
R Carryove r de tach able parts, such as vent
hoses, elbow fittings or term inal co vers from
th e battery being replaced.
R Make sure that theve nt hose is al ways con‐
nected tothe original opening on the side of
th e batter y.
Fit any existing or supplied cell caps.
Otherwise, gases or battery acid could
escape.
R Make sure that de tach able parts are recon‐
nected in the same way. To
w- starting or towing away Overview of
the permit tedto wing me thods *
NO
TEDama gefrom auto matic braking If one of
thefo llowing functions is switched
on, theve hicle brakes automatically in cer‐
ta in situations:
R Active Brake Assi st
R Active Dis tance Assi stDISTRONIC
R HOLD function
R Active Parking Assist
To avo id damage totheve hicle, deactivate
th ese sy stems in thefo llowing or similar sit‐
uations: #
During towing #
In a car wash Mercedes-Benz
recommends transporting your
ve hicle in the case of a breakdown, rath er than
to wing it away. Breakdown assis
tance 385

Closing
#
Check whe ther the seal is positioned cor‐
re ctly in the lid. #
Insert the lid into the brac ket at there ar of
th e fuse box. #
Fold down the lid of the fuse box and tighten
scr ews2. #
Close the bonn et. Opening and closing
the fuse box in the
cockpit The fuse box is on
the driver's side on the side of
th e cockpit under a co ver. #
Con tact a Mercedes-Benz Service Centre for
fur ther information. Opening and closing
the fuse box in the front
passenger foot we ll #
Contact a Mercedes-Benz Service Cent refor
fur ther information. Opening and closing
the fuse box in the load
compa rtment Obse
rveth e no tes on electrical fuses
(/ page 390). #
Open the side co ver. #
Remo vecover1.
The fuse allocation chart is on the side of the
fuse box. 392
Breakdown assi stance

#
Neverfit snow chains on the front
wheels. #
Only fit snow chains on there ar wheels
in pairs. *
NO
TEDama getocomponents of the
ve hicle body or chassis due tofitted
snow chains If
yo ufit snow chains tothe front wheels of
4MATIC vehicles, you may damage co mpo‐
nents of theve hicle body or chassis. #
Onlyfit snow chains tothere ar wheels
of 4MATIC vehicles. R
Snow chains are on ly permissible for cer tain
wheel/tyre combinations. You can obtain
information about this from a Mercedes-Benz
Service Cent re.
R For saf etyre asons, on lyuse sn owchains that
ha ve been specifically appr ovedfo ryo ur
ve hicle byMercedes-Benz, or snow chains
with the same quality standard. R
If sn owchains are fitted, the maximum per‐
missible speed is 50 km/h.
R Vehicles with Active Parking Assis t:do
not use Active Parking Assist when snow
ch ains are fitted.
R Vehicles with AIRMATIC or E- ACTIVE
BO DY CONT ROL:if sn ow ch ains are fitted,
only drive at raised vehicle le vel .
% You can permanently limit the maximum
ve hicle speed for driving with winter tyres
(/ page 236).
% You can deactivate ESP ®
to pull away
( / page 229). This allo wsthe wheels to
spin, achieving an increased driving forc e. Ty
re pressure Note
s on tyre pressure &
WARNING Risk of accident due toinsuf‐
fi cient or excessive tyre pressure
Ty res with either too low or too high a pres‐
sure present thefo llowing hazards:
R the tyres could bur st
R the tyres could wearexcessively and/or
une venly
R the driving characteristics as well as
st eering and braking characteristics may
be se verely impaired #
Obse rveth ere commended tyre pres‐
su res and check the tyre pressures of
all tyres including the spare wheel:
R monthly
R if altering the load on theve hicle
R prior tolong journe ys
R ifth e operating conditions change, for
ex ample when driving off- road 394
Wheels and tyres

#
Adjust the tyre pressure where neces‐
sar y. Ty
re pressure which is too high or too low can:
R Shor tenth e service life of the tyres.
R Cause increased tyre damage.
R Adversely af fect driving characteristics and
th us driving saf ety, e.g. due toaquaplaning. &
WARNING Risk of accident due torepea‐
te d pressure drop in the tyres
The wheels, valves or tyres could be dam‐
aged.
To o low a tyre pressure can lead tothe tyres
bur sting. #
Examine the tyres forfo re ign objects. #
Check whe ther the tyre has a puncture
or theva lve has a leak. #
Ifyo u are unable torectify the damage,
conta ct aqualified specialist workshop. Information on
there commended tyre pressure
fo rth eve hicle's factor y-fitted tyres can be found on
the tyre pressure table on the inside of the
fuel filler flap (/ page 395).
Use a suitable pressure gauge tocheck the tyre
pressure. The outer appearance of a tyre does
not permit any reliable conclusion about the tyre
pressure.
Only cor rect tyre pressures when the tyres are
cold. Conditions for cold tyres:
R The vehicle has been par ked with the tyres
out of direct sunlight for at least thre e hours.
R The vehicle has tr avelled less than 1.6 km.
The vehicle's tyres heat up when driving. As the
te mp erature of the tyres increases, so too does
th e tyre pressure.
Ve hicles with tyre pressure monitoring sys‐
te ms: you can also see the tyre pressure in the
driver's displa y.
Note s on trailer operation
Alw ays inflate there ar axle tyres tothere com‐
mended tyre pressures on the tyre pressure
ta ble for increased load. Ty
re pressure table The tyre pressure
table is on the inside of the
fuel filler flap. If one or more tyre sizes precede a tyre pres‐
sure, thefo llowing tyre pressure information is
only valid forth ose tyre sizes and their respec‐
tive load condition. Wheels and tyres
395

If
th e preceding tyre sizes are complemented by
th e+ symbol, the tyre pressure information
fo llowing sho wsalternative tyre pressures. Fuel
consum ption may then increase slightl y.
The load conditions "partially laden" and "fully
laden" are defined in theta ble for dif fere nt num‐
be rs of passengers and amounts of luggage. The
actual number of seats may dif fer from this. Ty
re pressure moni toring sy stem Fu
nction of the ty repressure moni toring sys‐
tem
The sy stem checks the tyre pressure and the
tyre temp erature of the tyres fitted totheve hicle
by means of a tyre pressu resensor.
The tyre pressure and the tyre temp erature
appear in the on-board computer (/ page 396).
If th ere is a subs tantial pressure loss or if the
tyre temp erature is excessive, you will be
wa rned in thefo llowing ways:
R via display messa ges (/ page 482).
R viatheh warning lamp in the instrument
clus ter (/ page 504) The tyre pressu
remonitoring sy stem is only an
aid. It is the driver's responsibility toset the tyre
pressure tothere commended cold tyre pressure
suitable forth e operating situation.
In most cases, the tyre pressure monitoring sys‐
te m will auto maticallyupdate the new refere nce
va lues af teryo u ha vechanged the tyre pressure.
Yo u can, ho wever,also update there fere nce val‐
ues byrestarting the tyre pressure monitoring
sy stem manually (/ page 397).
Sy stem limits
The sy stem may be impaired or may not function
particular lyin thefo llowing situations:
R the tyre pressure has been set incor rectly
R sudden pressure loss caused byafo re ign
object penetrating the tyre, forex ample
R there is a malfunction caused byano ther
ra dio signal source
Checking the ty repressure with the tyre
pressure moni toring sy stem
Re quirements:
R The ignition is switched on. On-board computer:
4 Service 5
Tyres
One of thefo llowing displa ysappears:
R Cur rent tyre pressure and tyre temp erature
of the individual wheels: R
Tyre pressures will be displayed after a few
minutes of driving
R Tyre pressure monitor active: thete ach-in
process of the sy stem is not yet compl ete.
The tyre pressures are already being moni‐
to re d. #
Compare the tyre pressure with there com‐
mended tyre pressure forth e cur rent operat‐ 396
Wheels and tyres

ing condition (/
page 395). Observethe
no tes on tyre temp erature (/ page 394).
% The values displa yed in the on-board com‐
puter may deviate from those of the tyre
pressure gauge as they referto sea le vel.At
high ele vations, the tyre pressure values
indicated bya pressure gauge are higher
th an those shown bythe on-board computer.
In this case, do not reduce the tyre pressure.
Re starting the ty repressure moni toring sys‐
tem
Re quirements:
R The recommended tyre pressure is cor rectly
set forth ere spective operating status on all
of the wheels (/ page 394).
Re start the tyre pressure monitoring sy stem in
th efo llowing situations:
R The tyre pressure has changed.
R The wheels or tyres ha vebeen changed or
newly fitted. On-boa
rdcompu ter:
4 Service 5
Tyres #
Swipe down wards on Touch Control on the
left-hand side of thesteering wheel.
The Use current pressures as new reference
values? message is shown in the multifunc‐
tion displa y. #
Torestart, press Touch Control on the left-
hand side of thesteering wheel.
The Tyre press. monitor restarted message is
shown in the multifunction displa y.
Cur rent wa rning messages are dele ted and
th eye llow h warning lamp goes out.
Af teryo u ha vebeen driving for a few
minutes, the sy stem checks whe ther the cur‐
re nt tyre pressures are wi thin the specified
ra nge. The cur rent tyre pressures are then
accep ted as refere nce values and monitored.
Be sure toalso pay attention tothefo llowing
re lated topic:
R Notes on tyre pressure (/ page 394) Wheel
change Note
s on selecting, fitting and replacing
tyres *
NO
TEMercedes-AMG vehicles #
Obser vethe no tes in the Supplement.
Yo u could otherwise failto recognise
dangers. &
WARNING Risk of accident due toincor‐
re ct dimensions of wheels and tyres
If wheels and tyres of the wrong size are
used, the wheel brakes or wheel suspension
components may become damaged. #
Alw aysre place wheels and tyres with
th ose that fulfil the specifications of the
original part.
When replacing wheels, make sure tofit the
cor rect:
R Designation
R Type Wheels and tyres
397

Note
s ontech nical data
* NO
TEMercedes-AMG vehicles #
Obser vethe no tes in the Supplement.
Yo u could otherwise failto recognise
dangers. The
tech nical da tawa s de term ined in accord‐
ance with EU Directives. The data stated on ly
applies tovehicles with standard equipment. Yo u
can obtain fur ther information from a Mercedes-
Benz Service Centre.
Only for ce rtain countries: you can find vehi‐
cle-specific vehicle data in the COC documents
(CERTIFIC ATE OF CONFORMITY). These pape rs
are included with theve hicle. On-board electronics
Note
s on tampering with the engine elec‐
tronics *
NO
TEPremature wearthro ugh improper
main tenance Improper maintenance may cause
vehicle
components towe ar more quickly and the
ve hicle's operating permit may be in valida‐
te d. #
Alw ays ha vewo rkon the engine elec‐
tronics and related components car ried
out at a qualified specialist workshop. Tw
o-w ayradios Note
s onfitting two-w ayradios &
WARNING Risk of accident due to
improper workon two-w ayradios
If two-w ayradios are manipulated or retrofit‐
te d incor rectl y,the electromagnetic radiation
from the two-w ayradios can inter fere with th
eve hicle electronics and jeopardise the
operating saf ety of theve hicle. #
You should ha veall workon electrical
and electronic components car ried out
at a qualified specialist workshop. &
WARNING Risk of accident from incor‐
re ct ope ration of two-w ayradios
If yo u use two- wayra dios in theve hicle
improperly, their electromagnetic radiation
can disrupt theve hicle's electronics. This is
true in thefo llowing situations, in particular:
R The two-w ayradio is not connec tedto an
ex terior aerial.
R The exterior aerial is fitted inco rrectly or
is not a lo w-reflection aerial.
This could jeopardise the operating saf ety of
th eve hicle. #
Have the lo w-reflection exterior aerial
fi tted at a qualified specialist workshop. Te
ch nical da ta413