2021 MERCEDES-BENZ GLS SUV check engine

#
Toswitc hon theignit ion:press butt on1
twic e.
The indic ator lam psintheins trument cluster
light up.
The ignit ionisswitc hedoffag ain ifone ofthe
fo llo wing condition sis me t:
R youdo notst ar tth eve hicle within
15 minut esand thetransmission isin posi‐
tion 005Dortheelectr icpar king brak eis
applied.
R youpr ess button1 once . St
arting theve hicl e St
arting theve hicl ewith thest ar t/s topbut‐
to n &
DANG ER Risk ofdeat hcause dby
ex haus tga ses
Combus tionengines emitpoisonous exhaus t
ga ses suchas carbon monoxide.Inhaling
th ese exhaus tga ses ishazar dous tohealt h
and leads topoisonin g. #
Neverlea vetheengine or,if pr esent ,
th eauxiliar yheating running inan
encl osedspa cewithout sufficie ntventi‐
la tio n. &
WARNIN GRisk offire due toflammab le
mat erial intheengine compartmen tor
th eex haus tsy stem
Flammable materials mayignit e. #
Ther efor e, checkre gular lythat ther e
ar eno flammab lemat erials inthe
engine compartmen tor on theex haus t
sy stem. Re
quirement s
R The Smar tKey islocat edintheve hicle and
th eSmar tKey batt eryis no tdisc harged. #
Shif tth etra nsmiss iontoposition 005Dor005C. #
Depr essthebr ak epedal andpress butt on
1 onc e. #
Ifth eve hicle does notst ar t:switc hof fnon-
essential consumer sand press butt on1
once. #
Ifth eve hicle still does notst ar tand the
Place theKey inthe Marked SpaceSee
Operator's Manualmessagealso appear sin
th emultifunc tiondispla y:star tth eve hicle
wit hth eSmar tKey inthemar kedspace
(emer gency operati on mod e)(/ page 169).
% Youcan switchoffth eengine whiledriving
by pressing button1 forabo utthre esec‐
onds orby pressing button1 thre etimes
wit hin thre esecon ds.Besureto obser vethe
saf etyno tesunder "Driving tips"
(/ page17 3).
St arting theve hicl ewith theSm artK ey inthe
ma rked spa ce(emer gency oper ation mode)
If th eve hicle does notst ar tand thePlace the
Key inthe Marked SpaceSeeOperator 'sManual
messag eappear sin themultifunc tiondispla y,
yo ucan star tth eve hicle inemer gency operati on
mod e. Dr
iving and parking 16
9

#
Mak esur eth at mar kedspace 2isem pty. #
Remo veSmar tKey 1 from theke yring. #
Place Sma rtKe y1 inmar kedspace 2next
to symbol 3.
The vehicle willstar taf te ra shor ttime.
If yo ure mo veSmar tKey 1 from mar ked
space 2theengine continues running .Fo r
fur ther vehicle star ts howe ver,Smar tKey 1 mus
tbe locat edinmar kedspace 2next to
symbol 3during theent ire jour ney. #
Have Smar tKey 1 checkedat aqu alif ied
spec ialistwo rkshop.
If th eve hicl edoes notst ar t: #
Place SmartKey 1 inmar kedspace 2and
lea veitth er e. #
Depr essthebr ak epedal andstar tth eve hi‐
cle using thest ar t/ stop butt on.
% Youcan also switchon thepo we rsupp lyor
th eignition withth est ar t/ stop butt on. St
arting theve hicl evia Remo teOnline serv‐
ices Cooling
orheating theve hicl eint erior before
co mmenci ngyour jour ney
Ensur eth efo llo wing beforest ar tin gth eengine:
R The legalstipulation sin thear ea wher eyo ur
ve hicle ispar kedallo wengin est ar tin gvia
smar tphon e.
R Itis saf eto star tand runth eengine where
yo ur vehicle ispar ked. R
The fuel tank issu fficien tly full.
R The star terbatt eryis suf ficie ntly charge d.
Char ging thest ar terbatt erybe fore star ting
th ejou rney
If th eve hicle batteryis disc harged, youre cei vea
messa geon your smar tphon e.Youcan then
st ar tth eve hicle withth esmar tphon eto charge
th ebatt ery. The vehicle isaut omatically
switc hedoffaf te rte nminu tes.
Ensur eth efo llo wing beforest ar tin gth eengine:
R The legalstipulation sin thear ea wher eyo ur
ve hicle ispar kedallo wengin est ar tin gvia
smar tphon e.
R Itis saf eto star tand runth eengine where
yo ur vehicle ispar ked.
R The fuel tank issu fficien tly full. 17
0
Driving and parking

Obser
vethefo llo wing ifyo umus tdr ive th ro ugh
wa ter:
R Obser vethemaximum permissible ford ing
dep th(/ pag e403).
R Drive at wa lkin gpace atmos t,other wise
wa tercan entertheve hicle interior orengine
com partment .
R Vehicles trave ling infront ,or onc omin gve hi‐
cles, cancreat ewav eswhic hma yexc eed the
maximu mper missi bledep thofthewa ter.
The braking effect of thebr ak es isreduced afte r
fo rd ing. Brak ecar efull ywhile paying attent ion to
th etra ffic con dition sunt ilbr akin gpo we rhas
been fullyrestor ed. No
teson off-r oad driving &
WARNIN GRisk ofacci dent ifyo udo not
ke ep toline offallon inclines
If yo udr ive at an ang leor tur non anincline,
th eve hicle could slipside ways,tip and roll‐
ove r. #
Alw aysdr ive on inclines intheline of
fa ll(s traight upordown) and donot
tur n. &
WARNIN GRisk offire due toflammab le
mat erials onhotpar tsof theex haus t
sy stem
Flammable material suc has lea ves, grass or
twigs mayignit eif th ey come intocont act
wi th hotpar tsof theex haus tsy stem. #
When driving onunpavedro ads oroff-
ro ad, regular lych eckth eve hicle under‐
side. #
Remo vetrap pe dplants orother flam‐
mable material, inpar ticular . #
Ifth er eis damag e,con sult aqu alif ied
spec ialistwo rkshop immediat ely. When
driving off-r oad, sand, mudandwateror
wa termix edwithoil ma yget intoth ebr ak es.
This maylead toare duction inbraking effect or
tot albrak efa ilur eas are sult ofincr eased wear.
The brakin gch aract eristic swill vary dependin g
on themat erial that has entered thesy stem. Clean
thebr ak es afte rdr iving off-r oad .If yo u
th en notice reduced braking effect or hea r
scr aping nois es,have thebr ak esy stem checked
at aqu alif ied spec ialistwo rkshop. Adaptyo ur
dr ivin gst yle to thech ang edbrakin gch aract eris‐
tic s.
* NO
TEDama gecau sed bydriving over
obs tacle s The
vehicle canbedamag edby:
R driving upont ohigh curbs orunpaved
ro ads.
R quickl ydr ivin gove robs tacle ssu ch as
cur bs, spee dbum psorpotholes.
R hea vyobject shittin gth eunderbody or
ch assis components. #
Donotdr ive ove robs tacle sth at coul d
damag eth eve hicle. #
Chec kth eve hicle regular lyfordama ge
dur ing off-r oad driving. #
Adjus tth eve hicle speed tosuit the
ro ad sur face condi tions. 17
6
Driving and parking

R
freq uent operation inmount ainouste rrain or
on poor road sur faces
R whe nth eengine isoftenleft idling forlong
per iods
R oper ation inpar ticula rly dus tycond ition s
and /orif air -rec ircula tion mod eis freq uen tly
used
In these orsimilar operating conditions ,ha ve the
int erior airfilt er ,engin eair clean er,engin eoil
and oilfilt er etc. chang edmor efreq uent ly.The
tir es mus tbe checkedmor efreq uentl yif th e
ve hicle isoper ated under increased loads. Fur‐
th er information canbeobt ained ataqu alif ied
spec ialistwo rkshop. Batt
erydisconne ctionperiods The
ASSYSTPL US service interva ldisp lay
can onlycalculat eth eser vice dueda te when
th ebat tery isconnect ed. #
Notedown theser vice duedatedispla yedon
th eins trument displaybef orediscon necting
th ebatt ery(/ page32 1). Engine
compartment Opening/closing
thehood &
WARNIN GRisk ofacci dent dueto driv‐
ing withth ehood unlocked
The hood mayopen andblockyo ur vie w. #
Neverre lease thehood when driving. #
Beforeev erytrip, ensur eth at thehood
is loc ked. &
WARNIN GRisk ofacci dent andinjury
when openingand closingthehood
The hood maysuddenl ydr op intoth eend
position .
Ther eis arisk ofinjur yfo ran yone inthe
hood's rang eof mo vement. #
Open orclose thehood onlywhen ther e
is nobody inthehood's rang eof mo ve‐
ment. &
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 GRisk ofinju rydue tomo ving
par ts
Com ponents intheengine compartmen tma y
con tinue running orstar tup sudden ly,ev en if
th eignition isswitc hedoff.
Mak esur eof thefo llo wing beforeper form ing
ta sk sin theengine compartmen t: #
Swi tchth eignition off. 322
Maintenanc eand care

#
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

&
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

Engine
Displa
ymes sages
Possible causes/conseq uencesand0050 0050
Solutions
To switch engine off,press
and hold Start/S topbut-
ton foratleast 3secon ds
or press 3times. *Y
ouhave pressed thest ar t/ stop butt onwhile theve hicle isin mo tion. #
Information aboutswitchingoffth eengine whiledriving (/page16 9).
00BD
Che ckCoo lant Level See
Opera tor'sManu al *T
hecoolant leve lis toolow.
* NO
TEEngi nedama gedue toinsuf ficie ntcool ant #
Avoid long journeys wit hins ufficie ntcool ant. #
Addcoolant (/page326 ). #
Have theengine cooling system checkedat aqu alif ied spec ialistwo rkshop.
ÿ
Coola ntToo HotStop Vehi-
cle Turn Engine Off *T
hecoolant istooho t. #
Pull overand stop theve hicle safely and switc hof fth eengine, paying attent ion toroad and traffic condi tions. &
WARNIN GDang erofburnswhen opening thehood
If yo uopen thehood when theengine hasoverheat edordur ing afire intheengine compartmen t,yo uco uld
co me intoco ntact withho tga ses orother escaping operating fluids. #
Beforeopen ingthehood, allowtheengine tocool down. Disp
lay mess ages and warning/ indic ator lam ps 423