engine MERCEDES-BENZ GLS 2021 Repair Manual

#
Drain of fan yex cess engineoilthat has been
added. Todo so, con sult aqu alif ied spec ialist
wo rkshop.
R For Engine OilLevel Switch Ignition On #
Switc hon theignition tocheckth eengine oil
le ve l.
R Engine OilLeve lSyst emInoperat ive:The oil
le ve lsen sor isdef ective or notcon nected. #
Consult aqu alif ied spec ialistwo rkshop.
R Engine OilLevel System Currently Unavail. #
Close thehood.
Re filling engine oil &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntsin theengine compart‐
ment canbevery hot,e.g. theengine, the
ra diat orand partsof theex haus tsy stem. #
Allo wtheengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. &
WARNIN GRisk offire and injuryfrom
eng ineoil
If eng ineoilcom esintocon tact with hot
com ponent partsintheengine compart‐
ment ,it ma yignit e. #
Mak esur eth at no eng ineoilisspille d
ne xt to thefiller open ing. #
Allo wtheengine tocool offand thor‐
oughl yclean theengine oilfrom com po‐
nen tpar tsbef orest ar tin gth eve hicle. *
NO
TEEngi nedama gecau sed byan
inc orrect oil filt er ,inc orrect oil oraddi‐
tiv es #
Donotus eengi neoilsor oil filt er s
whic hdo notcor respond tothespecif i‐
cation sex plicitl ypr escr ibed forth e
ser vice interva ls. #
Donotalt er theengine oiloroil filt er in
or der toachie velong erchang eint erva ls
th an presc ribed. #
Donotuse additiv es. #
Followtheins truction sin theser vice
int erva ldispla yre ga rding theoil
ch ang e. *
NO
TEDama gecau sed byrefilling too
muc hengine oil To
omuc hengine oilcan damag eth eengine
or thecat alytic converter . #
Have excess engineoilremo vedat a
qu alif ied spec ialistwo rkshop. %
Depending ontheengine, thecap maybe
ins talled intheengine compartmen tin dif‐
fe re nt locati ons. Ma
intena nce and care32
5

#
Turn cap 1cou nter-cloc kwiseand remo ve
it. #
Addengin eoil. #
Replace cap1and turnit cloc kwise untilit
eng ages. #
Chec kth eoil leve lag ain (/ page32 4). Chec
kingcoolant leve l &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntsin theengine compart‐
ment canbevery hot,e.g. theengine, the
ra diat orand partsof theex haus tsy stem. #
Allo wtheengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. &
WARNIN GRisk ofscal ding from hot
cool ant
If yo uopen thecap, youco uld bescalded. #
Letth emo torcool down beforeopening
th ecap. #
When opening thecap, wearprotect ive
gl ove sand safetygl asses . #
Open thecap slowlyto release pres‐
sur e. #
Park theve hicle onaleve lsur face. #
Checkth ecoolant temp eratur edispla yin the
ins trumen tclus ter.
The coolant temp eratur emus tbe inthebo t‐
to m quarterof thete mp eratur edispla y. #
Slowly turncap 1cou nter-clo ckwise to
re lease overpressur e. 326
Maintenance andcare

#
Con tinue turnin gcap 1count er-cloc kwis e
and remo veit.
The coolan tle ve lis cor rect inthefo llo wing
cases :
R ifth eengine iscold, thecoolant isup to
mar kerbar 2.
R ifth eengine iswa rm,th ecoolant isup to
0.6 in(1.5 cm) over mar kerbar 2. #
Ifnecessar y,add coolant that has been
appr ovedfo rMer cedes-Benz.
% Further information oncoolant
(/ page398) Ad
ding washer fluid tothewindsh ield
wa sher system &
WARNIN GRisk ofburnsfrom hotcom‐
ponent partsintheengine compartmen t
Cer tain com pone ntsin theengine compart‐
ment canbevery hot,e.g. theengine, the
ra diat orand partsof theex haus tsy stem. #
Allo wtheengine tocool down and only
to uc hco mp onent partsdescr ibedin
th efo llo wing. &
WARNIN GDang erofburnswhen open‐
ing thehood
If yo uopen thehood when theengine has
ove rheat edordur ing afire intheengine
com partmen t,yo uco uld come intoco ntact
wit hho tga ses orother escaping operating
fl uids. #
Beforeopen ingthehood, allowthe
engine tocool down. #
Intheeve ntofafire intheengine com‐
par tmen t,ke ep thehood closed and
call thefire ser vice. &
WARNIN G‑Ri sk offire and injuryfrom
wind shieldwa sher concen trat e
Wi ndsh ield wa sher concen trat eis highl y
fl ammab le.Itcoul dign ite if it com esinto
con tact with hotengine component partsor
th eex haus tsy stem. #
Mak esur eth at no wind shieldwa sher
concen trat espills outnext to thefiller
open ing. #
Remo vecap 1bytheta b. #
Addwa sher fluid.
R Further information aboutthewa sher fluid
(/ page39 9) Main
tenance andcare32
7

R
Parking AssistPA RK TRONI Cis rese tto the
pr ev iousl yselec tedse tting.
R Mer cedes-Ma ybachve hicl es:theru nning
bo ards remain retract ed.
R Vehicl eswith surround viewcamer a:the
fr ont imageisdeact ivat ed atspeeds above
11 mp h(1 8 km/h).
R Vehicl eswith AIRMA TIC:theve hicle islow‐
er ed tothepr ev iousl yse tch assis leve l.
R Vehicl eswith E-AC TIVE BODY CONT ROL:
th eve hicle islowe redto thepr ev iousl yse t
ch assis leve l. Ac
tiv atin g/deac tivatin gaut omati ccar wash
mode Re
quirement s:
R The vehicle isstatio nary.
R The engine isrunning . Mu
ltimed iasystem:
4 © 5
Set ting s5
Quick Access
Ac tiv atin gaut omati ccar wash mode #
Select AutomaticCarWash Mode. #
Select Start .
If one ofthese ttings cann otbe select ed,this is
displa yedby a% behindth ere spectiv ese t‐
ting.
% Foran overvie wof these ttings made when
activ ating automatic carwash mode
(/ page328).
Deactiv atingautomatic carwash mode #
Select Stop.
The automatic carwash settin gsarere se t.
% The automatic carwash mode isaut omati‐
cally deactiv ated assoon asaspeed of
12 mp h(20 km/h) isexc eeded. No
teson using apo we rwa sher &
WARNIN GRisk ofan acci dent when
us ing powe rwa sher swit hro und -spr ay
nozzl es
The waterje tcan caus eex tern all yin visi ble
damag e.
Com ponentsdamag edinthis wa yma yune x‐
pec tedly fail. #
Donotuse apo we rwa sher withro und -
spra yno zzles. #
Have damag edtires orchassis parts
re placed immediat ely. To
avo iddamag eto your vehicle, observethefo l‐
lo wing when usingapo we rwa sher :
R Keep theSmar tKey atleas t10 ft(3 m) away
fr om theve hicle. Other wise theta ilg ate
could openunintentio nally.
R Maint ainadis tance ofat leas t11 .8 in
(30 cm) totheve hicle.
R Vehicl eswith decorativ efo il: par tsof your
ve hicle areco veredwit hadecora tivefo il. 330
Maintenanceand care

Risk
ofexplosion. Fir
e,open flames andsmokingar e
pr ohibi tedwhen handling thebatt ery.
Av oid creating sparks. Ele
ctroly teor batt eryacid iscor ro‐
siv e.Avoid cont actwithth eskin ,eye s
or clo thing. Wearsuit able protect ive
clo thing, inpar ticular glove s,an
apr onand afa ce mas k.Immedia tely
ri nse electr olyteor acid splashes off
wit hclean water.Con sult adoc torif
necessar y. We
arsaf etygl asses . Ke
ep childr enaway. Obser
vethis Opera tor's Manua l.
Obser vethefo llo wing ifyo udo notint endto use
th eve hicle overan extende dpe riod oftime:
R Activatest andb ymode .
R Alternat ivel y: con nectth ebatt eryto abat ‐
te ry charge rapp rove dby Mer cedes-Ben zor
consult aqu alif ied spec ialistwo rkshop to
discon nectth ebatt ery. No
teson star ting assistance andchargin g
th e12 Vbatt ery Ve
hicl eswith alithium-ion battery
When chargin gth ebatt eryand during star tin g
assis tance, alwa ys use thejum p-startconne c‐
tio npo int intheengine compartmen t. *
NO
TEDama ging thebatt eryth ro ugh
ove rvolt age When
chargin gusin gabat tery charge rwit h‐
out amaximu mchargin gvo ltag e, thebatt ery
or theve hicle electr onics maybe damag ed. #
Onlyuse batterych arge rs wit hamax i‐
mum chargin gvo ltag eof 14.8 V. All
other vehicl es
When chargin gth ebatt eryand during star tin g
assis tance, alwa ys use thejum p-start connec‐
tion pointintheengine compartmen t.
* NO
TEDama ging thebatt eryth ro ugh
ove rvolt age When
chargin gusin gabat tery charge rwit h‐
out amaximu mchargin gvo ltag e, thebatt ery
or theve hicle electr onics maybe damag ed. #
Onlyuse batterych arge rs wit hamax i‐
mum chargin gvo ltag eof 14.8 V. Br
ea kdo wnassista nce 34
5

&
WARNIN GRisk ofexplosion from hydro‐
ge nga signiting
Ther eis adang erofhydrog en gasigniting
when chargin gth ebatt eryif th er eis ashor t
cir cuit orspar ksstar tto form . #
Mak esur eth at thepositiv ete rm inal of
th econ nect edbatt erydoes notcome
int ocon tact with vehicle parts. #
Neverpla ceme talobje ctsor tools ona
batt ery. #
The descr ibedorder ofthebatt ery
clam psmus tbe obser vedwhen con‐
nec tingand discon nectingth ebatt ery. #
When giving star tin gassis tance, alwa ys
mak esur eth at youon lyconnect bat‐
te ry term inals withident icalpolar ity. #
Dur ing star tin gassis tance, youmus t
obse rveth edescr ibedorder forcon‐
necting anddisconnecting thejum per
cable. #
Donotcon nect ordiscon nectthebat‐
te ry cla mp swhile theengine isrunning . &
WARNIN GRisk ofexplosion during
ch argin gpr oce ssand star tin gassis tance
Dur ing thech argin gpr oce ssand star tin g
assis tance, thebatt eryma yre lease anexplo‐
siv ega smixtur e. #
Avoid fire ,open flames ,cr eat ing spar ks
and smoking. #
Mak esur eth er eis suf ficie ntventil a‐
tio n. #
Donotle an ove ra batt ery. &
WARNIN GRisk ofexplosion from afro‐
zen battery
A disc hargedbatt eryma yfreeze attemp era‐
tur es slightl yabo veorbelo wfreezing point.
Dur ing star tin gassis tance orbatter ych arg‐
ing ,bat tery gascan bereleased. #
Alw aysallo wabatt eryto thaw before
ch argin git or per form ing star tin gassis ‐
ta nce. If
th eindicat or/warning lampsintheins trument
clus terdo notlig ht up atlow temp eratur es,itis
ve ry likelyth at thedisc hargedbatt eryhas fro‐
zen .In this case youma yne ither jump-start the
ve hicle norcharge thebatt ery.
The service life of abatt eryth at has been
th awe dma ybe dramaticall yshor tened .The
st ar tin gch aract eristic sma ybe impair ed,espe ‐
ciall yat low temp eratur es.
It is recomme ndedthat youha ve ath aw ed bat‐
te ry checkedat aqu alif ied spec ialistwo rkshop.
All vehicl es
* NO
TEDama gecau sed bynum erou sor
ex tende datt em ptsto star tth eengine Nu
me rous orextende datt em ptsto star tth e
engine maydamag eth ecat alytic converter
due tonon-co mbusted fuel. #
Avoid numer ousand extende datt em pts
to star tth eengine. 34
6
Brea kdo wnassista nce

Obser
vethefo llo wing pointsdur ing star tin g
assis tance and when chargin gth ebatt ery:
R Onlyuse undamag edjum per cables/c harg‐
ing cables withasuf ficie ntcross -secti onand
insu late dte rm inal clam ps.
R Non-insulat edpar tsof thete rm inal clam ps
mus tno tcom eint ocon tactwi th other metal
par tswhile thejum per cables/c harging
cable iscon nect edtothebatt ery/jum p-start
connecti onpoint.
R The jumper cable/c harging cablemus tno t
come intocont actwith anypar tswhic hma y
mo vewhen theengine isrunning .
R Alw aysmak esur eth at nei ther youno rth e
batt eryis elect rostatic allych arge d.
R Keep away from fire and open flames .
R Donotlean overth ebatt ery.
Obser vetheadditional follo wing pointswhen
ch argin gth ebatt ery:
R Onlyuse batterych arge rs tested and
appr ovedfo rMer cedes-Benz.
R Read thebatt erych arge r's oper ating instruc‐
tions beforech argin gth ebatt ery. Obser
vetheadditional follo wing pointsdur ing
st ar tin gassis tance:
R Startin gassis tance mayonly beprov ided
using vehicles, batteries orother jumpstar t
de vic es wit hano min alvoltag eof 12 V.
R The vehicles mustno tto uc h.
R Vehicl eswith aga soline engine: Jump-
st ar tth eve hicle onlywhen theengine and
ex haus tsy stem arecold. St
arting assistance andchargin gth e12 V
batt ery Re
quirement s:
R The vehicle issecur edwithth eelectr icpar k‐
ing brak e.
R Vehicl eswith automatic transmiss ion:
The transmis sionisin posi tion 005D.
R The igniti onand allele ctrical consumer sar e
swi tched off.
R The hood isopen. Ex
am ple:engine compartment #
Slid eco ver1 ofposi tiveclam p2 onthe
jum p-starting con nection point inthedir ec‐
tion ofthear row . #
Con nect posi tiveclam p2 onyour vehicle to
th epositiv epole ofthedonor batteryusing
th ejum per cable/c harging cable. Always Br
ea kdo wnassista nce 34
7

begin
withpositiv eclam p2 onyour ow n
ve hicle firs t. #
During star ting assistance :st ar tth e
engine ofthedonor vehicle andrunat idle
spe ed. #
Connect theneg ativepole ofthedonor bat‐
te ry and grou nd point 3 ofyour ow nve hicle
by usin gth ejum per cable/c harging cable.
Begin withth edonor batteryfirs t. #
During star ting assistance :st ar tth e
engine ofyour ow nve hicle. #
Dur ing thech argin gpr oc ess :st ar tth e
ch argin gpr oce ss. #
Dur ing star ting assistance :le tth eengines
ru nfo rse veralmin utes. #
Dur ing star ting assistance :bef oredis con‐
necting thejum per cable, switchon anelec‐
tr ical consumer inyour ow nve hicle, e.g.the
re ar wind owheat eror lighting.
When thest ar tin gassis tance/c harging proce ss
is com plet e, per form thefo llo wing steps: #
First,re mo vethejum per cable/c harging
cable from ground point 3and theneg ative
pole ofthedonor battery, then from positiv e
clam p2 and thepositiv epole ofthedonor
batt ery. Begi nea ch tim ewi th thecon tacts
on your ow nve hicle firs t. #
Afterre mo ving thejum per cable/c harging
cable, closecover1 ofposi tiveclam p2.
Fu rther information canbeobt ained ataqu ali‐
fi ed specialis two rkshop. Re
plac ingthe 12Vbatt ery #
Obs erve theno teson the12 Vbatt ery
(/ page343).
Mer cedes-Benz recomme ndsthat youha ve the
12 Vbatt eryre placed ataqu alif ied spec ialist
wo rkshop, e.g.atan aut hor ized Mercedes-Benz
Cent er. Obser
vethefo llo wing notesif yo uwa ntto
re place thebatt eryyo urself :
R Alw aysre place afa ulty battery wit habatt ery
whic hmee tsthespecif icvehicle requ ire‐
men ts.
The vehicle iseq uipped withan AGMtech nol ‐
ogy batter y(A bso rbentGlas sMa t)or alith ‐
ium-io nbatt ery. Fu llve hicle functionality is
onl yguar anteed withan AGMbatt eryor lith‐
ium-ion battery. Fo rsaf etyre ason s,
Mer cedes-Ben zre comme ndsthat youon ly
use batteries whic hha ve been tested and
appr ovedfo ryo ur vehicle byMer cedes-Ben z.
R Carryove rde tach able parts,suc has vent
hos es,elbo wfitting orterm inal covers from
th ebatt erybeing replaced.
R Mak esur eth at theve nt hos eis alwa ys con‐
nect edtotheor iginal opening ontheside of
th ebatt ery.
Ins tallan yex istin gor supplied cellcaps.
Ot her wise, gases orbatt eryacid could
escape.
R Mak esur eth at detach able partsarere con‐
nect edinthesame way. 34
8
Brea kdo wnassista nce

To
wing away theve hicl ewith both axle son
th egr ound #
Obser vetheno teson theper mitt edtowing
me thods (/page349). #
Mak esur eth at thebatt eryis con nect edand
ch arge d.
A disc hargedbatt eryhas thefo llo wing effects:
R The enginecanno tbe star ted
R The electr icpar king brak ecann otbe
re leased orapplied
R The automat ictransmissio ncan notbe shif‐
te dto position 005Cor005D
% Ifth eaut omatic transmiss ioncann otbe shif‐
te dto position 005C,orthemultifunc tiondis‐
pla yin theins trument clusterdoes notsho w
an ything, theve hicle mustbe transpor ted
aw ay (/ pag e35 1). Atowing vehicle with
lif ting equipment isrequ ired forve hicle
tr anspor tatio n. *
NO
TEDama gedue totowing away at
exc essiv elyhigh speeds orove rlong dis‐
ta nces The
drivet ra in could bedamag edwhen tow‐
ing atexc essiv elyhigh speeds orover long
dis tances. #
Atowing speed of30 mph(50 km/h)
mus tno tbe exc eeded. #
Atowing distan ceof30 miles(50 km)
mus tno tbe exc eeded. &
WARNIN GRisk ofacci dent whento wing
a ve hicle whichis toohea vy
If th eve hicle being tow- star tedor towe d
aw ay ishea vier than theper missible gross
mass ofyour vehicle, thefo llo wing situat ions
can occur:
R The towing eyema ybecome detach ed.
R The vehicle/tr ailercombination may
sw erve oreve nov ertur n. #
Ifano ther vehicle istow- star tedor
to we daw ay,its weight mustno texc eed th
eper missible gross mass ofyour ow n
ve hicle. #
Information ontheper missible gross mass of
th eve hicle canbefound ontheve hicle iden‐
tif ication plate(/ page392). #
Donotopen thedr iver's door orfront
passeng erdoor astheaut omatic transmis‐
sion mayot her wise shiftto position 005Dauto‐
matic ally. #
Installth eto wing eye(/ page353). #
Fasten theto w bar .
* NO
TEDama gedue toinc orrect connec‐
tion oftheto w bar #
Onlyconnect theto w rope ortow bar to
th eto wing eyes. %
Youcan also attachth eto w bar tothetrailer
hitc h. #
Deact ivat eth eaut omatic locking mechanism
(/ page72 ). #
Donotactiv ateth eHOLD function. 350
Breakdo wnassis tance

Ins
tallin gth eto wing eye #
Press themar kon cover1 inwa rdsand
re mo ve. #
Screw intheto wing eyecloc kwiseasfaras it
wil lgo and tight en.
Ve hicl eswith atraile rhitc h:Vehicles witha
tr ailer hitchdo notha ve are ar brac ketfo rth e to
wing eye. Fasten theto w bar tothetrailer
hitc h.
% Mak esur eth at cover1 eng ages inthe
bum perwhen youre mo vetheto wing eye.
* NO
TEDama getotheve hicle dueto
inc orrect useof theto wing eye When
ato wing eyeis used toreco vera ve hi‐
cle, theve hicle maybe damag edinthepr oc‐
ess. #
Onlyuse theto wing eyeto tow aw ay or
to w star tth eve hicle. To
w star ting theve hicl e(eme rgency engine
st ar t) Ve
hicl eswith automatic transmiss ion
* NO
TEDama getotheaut omatic trans‐
mission duetotow star tin g The
automat ictransm issionma ybe damag ed
in thepr ocess oftow star tin gve hicles with
aut omatic transmission. #
Vehicles withaut omatic transmission
mus tno tbe tow star ted. #
Vehicles withaut omatic transmission must
no tbe tow- star ted. Electr
icalfuses No
teson electr icalfuses &
WARNIN GRisk ofacci dent andinjury
due tooverloaded lines
If yo uman ipulat eor bridg eafa ulty fuse orif
yo ure place itwit hafuse withahigher
am per age, theelectr icline could beove rloa‐
ded.
This could result inafire . #
Alw aysre place faulty fuseswit hspec i‐
fi ed newfuses containin gth ecor rect
am per age. Br
ea kdo wnassista nce 35
3