2020 MERCEDES-BENZ C-CLASS CABRIOLET ECU

Ne
wtirepr essur esensor s,e.g. inwint ertires,
ar eaut omatically taught -indur ing thefirs tjou r‐
ne yth ey areused.
The tirepr essur eand thetir ete mp eratur e
appear inthemultifunc tiondispla y
(/ page39 4).
If th er eis asubs tantia lpr ess ureloss orifth e
tir ete mp eratur eis exc essiv e,youwill bewarned
in thefo llo wing ways:
R viadisp lay messa ges(/ page469)
R viathe0077 warning lam pin theins trument
clus ter(/ page49 7)
The tirepr essu remonit oring system isonl yan
aid. Itis thedr iver's responsibili tyto setth etir e
pr essur eto there comme ndedcoldtirepr ess ure
su itab leforth eoper ating situation .Se tth etir e
pr essur efo rcold tires using atir epr essu re
ga ug e. No tethat thecor rect tirepr ess urefo rth e
cur rent operati ng situa tionmu stfirs tbe taught -
in to thetir epr essur emonit oring system.
In mos tcases, thetir epr essur emonit oring sys‐
te m wil lau tomatical lyupd ateth ene wrefere nce
va lues afte ryo uha ve chang edthetir epr essur e.
Yo ucan ,ho we ver,also updat eth ere fere nce val‐ ues
byrestar tin gth etir epr essur emonit oring
sy stem manually (/page395).
Sy stem limit s
The system maybe impair edorma yno tfunc tion
in thefo llo wing situat ions:
R thetir epr essur ehas been setincor rectl y
R ther eis asudden pressur eloss caused, for
ex am ple, byafo re ign obje ctpene tratin gth e
tir e
R ther eis amalfunct ioncaused byano ther
ra dio signal source
Mak esur eto obser vethefo llo wing further rela‐
te dsubjec t:
R noteson tirepr essur e(/ page390)
Chec kingthetir epr essur ewit hth etir epr es‐
sur emoni toring system
Re quirement s:
R The ignit ionisswitc hedon. On-
boar dcom puter:
4 Service 5
Tires
One ofthefo llo wing displa ysappear s:
R Cur rent tirepr ess ureand tirete mp eratur eof
th eindividual wheels: R
Tire pressure willbedisplayed afterdriving a
few minutes
R Tire Pressure MonitorAct ive: thete ac h-in
pr oce ssofthesy stem isno tye tcomple te.
The tirepr essur esarealr eady being moni‐
to re d. #
Com pareth etir epr essur ewit hth ere com‐
mend edtirepr ess urefo rth ecur rent operat‐ 39
4
Whe elsand tires

ing
con dition (/page39 1). Obser vethe
no teson tirete mp eratur e(/ page390).
% The values displa yedin themultifunc tiondis‐
pla yma yde viat efrom those ofthetir epr es‐
sur ega ug eas they referto sea leve l.At high
altitudes, thetir epr essur eva lue indic ated by
a pr essur ega ug ear ehigh erthan those
sho wnbytheon- boar dcom puter.In this
case, donotre duce thetir epr essur e.
Mak esur eto obser vethefo llo wing further rela‐
te dsubjec t:
R Noteson tirepr essur e(/ page390)
Re star ting thetir epr essur emoni toring sys‐
te m
Re quirement s:
R The recomme ndedtirepr ess ureis cor rectl y
se tfo rth ere spectiv eoper ating status on
eac hof thefo ur wheel s(/ page39 0).
Re star tth etir epr essur emonit oring system in
th efo llo wing situat ions:
R The tirepr essur ehas chang ed.
R The wheels ortires have been chang edor
ne wlyins talled. On-
boar dcom puter:
4 Service 5
Tires #
Swipe down wardson Touc hCon trol on the
lef t-hand sideofthesteer ing wheel.
The Use Current Pressures asNew Refer-
ence Values? messageis sho wninthemulti‐
func tion displa y. #
Tobegin restar t,pr ess Touc hCon trol on the
lef t-hand sideofthesteer ing wheel.
The Tire Press. MonitorRestart edmessag eis
sho wninthemultifunc tiondispla y.
Cur rent wa rning mess ages aredele tedand
th eye llo w0077 warning lam pgoes out.
Af teryo uha ve been driving fora fe w
minut es,thesy stem checks whe ther thecur‐
re nt tirepr ess ures arewi thin thespecif ied
ra ng e. The current tirepr ess ures areth en
accep tedas refere nce values andmon itor ed.
Mak esur eto obser vethefo llo wing further rela‐
te dsubjec t:
R Noteson tirepr essur e(/ page390) Ra
dio -equipme ntappr oval of thetir epr es‐
sur emoni toring system
Ra dio equipme ntappr oval number s Co
untr yR adiotype approval number
Ca nada IC:2546A -GG4T
IC: 2546A -DG6W2D4
IC: 2546A -MC34MA4
US AF CCID:MRXGG4 T
FCC ID:MRXD G6W2D4
FCC ID:MRXM C34MA4 Fu
rther information onthedeclar ationofcon ‐
fo rm ity forwir eles sve hicle component s
(/ page26). Ti
re pres sur elo ss wa rning system Fu
nction ofthetir epr essur eloss warning
sy stem
The tirepr essur eloss warning system warnsth e
dr iver by means ofdisp lay messa geswhen ther e
is ase vere tirepr es su re loss. Wheels
andtires 395

Un
ifor m Tire Quality Grading Standar ds:a
unif orm standar dto grade thequ alit yof tires
wit hre ga rd totrea dqu alit y,tiretracti onand
te mp eratur ech aract eristic s.The qualit ygr adin g
asses smentismade bythemanuf acturerfollo w‐
ing spec ificat ions from theU. S. government. The
qu alit ygr ade ofatir eis im print ed on theside
wa llof thetir e.
Re comm endedtir epr essu re:th ere comme n‐
ded tirepr ess ureis thetir epr essur especif ied
fo rth etir es mount edtotheve hicle atthefa c‐
to ry.
The tireand information table con tains there c‐
omme ndedtirepr ess ures forcold tires, themax‐
imum permissible loadandthemaximum per‐
missible vehicle speed.
The tirepr essur eta ble con tains there comme n‐
ded tirepr ess ures forcold tires under various
oper ating condit ions,i.e.loading and/orspeed
of theve hicle.
Incr eased vehicl ewe ight duetooptiona l
eq uip ment :th ecombin edweight ofall standar d
and optio nal equipme ntavailable forth eve hicle, re
ga rdless ofwhe ther itis actually installed on
th eve hicle ornot.
Rim: thepar tof thewheel onwhic hth etir eis
ins talled.
GA WR (Gross AxleWe ight Ratin g):th eGA WR
is themaximum permissible axleload. The
actual loadonanaxle mustne verexc eed the
gr os saxle weight rating .The gross axlewe ight
ra ting canbefound ontheve hicle identif ication
plat eon theB‑pillar onthedr iver's side.
Speed ratin g:thespeed rating ispa rtof thetir e
identif ication .It specif iesthespeed rang efo r
whic hatir eis appr oved.
GV W(Gr oss Vehicl eWe ight ):th egr oss vehicle
we ight comprises thewe ight oftheve hicle
including fuel,tools, thespar ewheel, accesso‐
ri es installed, occupant s,lugg ageand thetrailer
dr aw bar nose weight ,if applicable. Thegros s
ve hicle weight mustno texc eed thegr oss vehicle
we ight rating GVWR asspecif iedontheve hicle
identif ication plateon theB‑pillar onthedr iver's
side.
GV WR (Gross Vehicl eWe ight Ratin g):th e
GV WR isthemaximum permitt edgross weight of
thefully laden vehicle (weight oftheve hicle
including allaccessor ies,occupants, fuel,lug‐
ga ge and thetrailer draw bar nose weight ifappli‐
cable). Thegros sve hicle weight rating issp eci ‐
fi ed on theve hicle identif ication plateon the
B‑pil laron thedr iver's side.
Maxim umweight ofthelad envehicl e:the
maximu mwe ight isthesum ofthecurb weight
of theve hicle, thewe ight oftheaccesso ries, the
maximu mloa dand thewe ight ofoption aleq uip‐
men tins talled atthefa ct or y.
Kilop ascal(kP a):metric unit fortir epr essu re.
6.9 kPacor responds to1psi .Ano ther unit for
tir epr es su re isbar .10 0kilop ascal(kP a)equals
1 bar .
Lo ad inde x:inadd ition totheload-bear ing
inde x,theload indexma yalso beimprint ed on
th eside wallof thetir e. This specif iestheload-
bear ingcapacity ofthetir emor epr ecisel y.
Cur bwe ight :th ewe ight ofave hicle withstand‐
ar deq uipme ntinc ludin gth emaximum capacity
of fuel, oiland coolant .It also includes theair
con ditionin gsy stem and option aleq uipment if Wheels
andtires 40
7

th
ese areins talled ontheve hicle, butdoes not
include passeng ersor lugg age.
Maximum tireload: themaximum tireload is
th emaximum permissible weight inkilog rams or
lbs forwhi chatir eis appr oved.
Maxim umpermissible tirepr essur e:maxi‐
mum permissible tirepr essur efo rone tire.
Maximum loadonone tire: maximu mloa don
one tire. This iscalcu lated bydividing themaxi‐
mum axleload ofone axle bytwo.
PSI (pounds persquar ein ch ):standar dunit of
meas uremen tfo rtir epr essu re.
Aspe ctratio :ra tio betwee ntire height and tire
wi dthin pe rcent .
Ti re pres sur e:press ureinsi dethetir eappl ying
an outw ardfo rc eto eve rysquar einc hof thetir e.
The tirepr essur eis specif iedinpounds per
sq uar einc h(psi), inkilopascals (kPa)or inbar .
The tirepr essur eshould onlybe cor rected whe n
th etir es arecold.
Cold tirepr essur e:thetir es arecold when the
ve hicle hasbeen parkedfo rat lea st3hou rs wit
hout direct sunli ghtonthetir es ortheve hicle
has been driven forless than 1mile (1.6 km ).
Ti re contact surface: thepar tof thetir eth at
com esintocon tact with thero ad.
Ti re bead: thepur pose ofthetir ebead isto
ensur eth at thetir esits secur elyon thewheel
ri m. Ther ear ese veralwir ecor esinthetir ebead
to preve ntthetir efrom chang inglengthon the
wheel rim.
Side wall:thepar tof thetir ebe tween thetread
and thetir ebead.
We ight ofoptiona leq uipm ent:th ecombin ed
we ight oftheop tion aleq uipment weighin gmor e
th an there placed standar dpar tsand moreth an
5 lbs (2.3kg ).This optional equipment, suchas
high-per form anc ebr ak es, leve lcon trol system, a
ro of lugg agera ck orhigh-per form anc ebat teries,
is no tincluded inthecurb weight andthewe ight
of theaccessor ies.
TIN (Tire Identif ication Numbe r):auni que
ident ificat ion numb erwhic hcan beused bya
tir ema nuf actu rerto ident ifytires, forex am ple,
in apr oduc tre cal l,and thus iden tifyth epur‐
ch aser s.The TINismade upofthemanuf actur‐ er's
identit ycode, tiresize, tiretype code and
th emanuf acturingdate.
Load-bear inginde x:theload-bear inginde xis a
code that con tains themaximum load-bearing
capacity ofatir e.
Tr actio n:traction isthegr ip resulting from fric‐
tion between thetir es and thero ad sur face.
We arindi cator:nar row bars(tr ead wearbar s)
th at aredis tribut edove rth etir econ tact surface.
If th etir etread isleve lwit hth ebar s,thewe ar
limit of1/ 16 in(1.6 mm) hasbeen reac hed.
Dis tribut ionofvehicl eoc cupants: distribu tion
of vehicle occupants over designat edseat posi‐
tion sin ave hicle.
Maximum permissible payload weight :nom i‐
nal load andluggageload plus150lb (68 kg)
multip liedby thenumber ofseats intheve hicle. 408
Wheels andtires

#
Adaptyo ur drivin gst yle accor dinglyand
dr ive car efull y. #
Nevermount moreth an oneemer gency
spa rewheel orspar ewheel that dif fers
in size . #
Onlyuse anemer gency sparewheel or
spar ewheel ofadif fere nt size briefly. #
Donotsw itchof fESP ®
. #
>Ha vetheemer gency sparewheel or
spar ewheel ofadif fere nt size replaced
at thenear estqu alif ied spec ialistwo rk‐
shop. Thenewwheel mustha ve the
cor rect dimensi ons. Ch
eckth etir epr essur eof theemer gency spare
wheel installed. Correct thepr essur eas neces ‐
sar y.
The maximum permissible speedwithan emer‐
ge ncy sparewheel installed is50 mph
(80 km/ h).
Do notins tallth eemer gency sparewheel with
sn ow chains . Re
place theemer gency sparewheel afte rsix
ye arsat thelat est,re ga rdless ofwe ar.
% Ve
hicl eswith atir epr ess urelos swa rn‐
ing system: Ifan emer gency sparewheel is
ins talled thetir epr essur eloss warning sys‐
te m canno tfunction reliabl y.Onl yre star tth e
sy stem again when theemer gency spare
wheel hasbeen replaced withane wwheel.
Ve hicl eswith atir epr ess uremonit oring
sy stem: Ifan emer gency sparewheel is
ins talled thetir epr essur emonit oring system
cann otfunction reliabl y.Fo ra fe w min utes
af te ran emer gency sparewheel isins talled,
th esy stem mayst ill displa yth etir epr essur e
of there mo vedwheel. Onlyre star tth esy s‐
te m again when theemer gency sparewheel
has been replaced withane wwheel.
Be sureto also obse rveth efo llo wing further
re lat ed subje cts:
R Noteson tirepr essur e(/ page390)
R Tire and Loadi ngInfo rm atio nplacar d
(/ page39 7)
R Tire pressur eta ble (/ page39 1) Re
mo ving the eme rgency sparewheel The
eme rgency sparewheel issecur edinthe
emer gency sparewheel baginthetrunk . #
Obser vetheinf ormation onmount ingtires
(/ page409). #
Open thetrunk . #
Detach thesecur ingstra ps. #
Unhook there tainin gspr ing hook sof the
secur ingstra ps from thebr ac kets. #
Remo vetheemer gency sparewheel bagwith
th eemer gency sparewheel. #
Open theemer gency sparewheel bagand
re mo vetheemer gency sparewheel. Wheels
andtires 41
9

Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions
0049 (US Aonl y)
0024 (Canada only)
Parking BrakeSeeOpera-
tor's Manual *
The yello w0024 indicator lam pis lit. The elect ric pa rking brak eis malfun ctionin g.
To appl y: #
Swi tchof fth eignition andturnit bac kon. #
Appl yth eelectr icpar king brak emanually (/page16 0).
If it is no tpo ssi ble to appl yth eelectr icpar king brak e: #
Consult aqu alif ied spec ialistwo rkshop. #
Wher enecessar y,also secureth epar kedve hicle agains tro lling away.
* The yello w0024 indicator lam pand there d 0049 (USAonl y)or 0024 (Canada only)indicat orlam par elit. The
elect ric pa rking brak eis malfun ctionin g.
To release: #
Swit choffth eignition andturnit bac kon. #
Release theelectr icpar king brak emanually (/page16 0).
or #
Release theelectr icpar king brak eaut omaticall y(/ page15 9).
If it is still no tpossible torelease theelectr icpar king brak e: #
Donotcon tinue driving under anycir cums tances. Consu ltaqu alif ied spec ialistwo rkshop.
* The yello w0024 indicator lam pis lit and there d0049 (USAonl y)or 0024 (Canada only)indicat orlam pis flashin g.
The electric par kingbr ak eis malf unctionin g.
The electric par kingbr ak ecoul dno tbe applied orreleased. 44
0
Dis play messa gesand warning/ indic ator lam ps

Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions #
Switc hof fth eignition andturnit bac kon.
To appl y: #
Release andthen apply theelectr icpar king brak emanuall y(/ page16 0).
To release: #
Appl yand then release theelectr icpar king brak emanuall y.
If th eelectr icpar king brak ecann otbe applied orthere d0049 (USAonl y)or 0024 (Canada only)indicat orlam p
con tinues toflash: #
Donotcon tinue drivin gunde ran ycir cum stanc es.Con sult aqu alif ied spec ialistwo rkshop. #
Wher enecessar y,also secureth epar kedve hicle agains tro lling away.
* The yello w0024 indicator lam pis on and there d0049 indicat orlam p(US Aonl y)or 0024 indicat orlam p(Can‐
ada only)flashes forapp roxima tely tenseco ndsafte rth eelectr icpar king brak ehas been applied orreleased. It
th en remains litor goes out.Theelectr icpar king brak eis malfu nctioning.
If th ebat tery charge leve lis toolo w: #
Char gethebatt ery.
To appl y: #
Swi tchth eignition off.
The electr icpar king brak eis applied automaticall y. Dis
play messa gesand warning/ indic ator lam ps 44
1

Disp
laymes sages
Possible causes/conseq uencesand0050 0050
Solutions
If th eelectr icpar king brak eshould notbe applied, e.g.when washing theve hicle inan aut omatic carwash orwhen
ha ving theve hicle towe d,lea vetheignition switchedon.This does notinclude having theve hicle towe dwit hth e
re ar axle raised.
If th eelectr icpar king brak eis no tapplied automaticall y: #
Switc hof fth eignition andturnit bac kon. #
Release andthen apply theelectr icpar king brak emanuall y(/ page16 0).
If it is still no tpossible toappl yth eelectr icpar king brak e: #
Consult aqu alif ied spec ialistwo rkshop. #
Wher enecessar y,also secureth epar kedve hicle agains tro lling away.
To release: #
Ifth econ ditions forau tomatic release arefulf illed andtheelectr icpar king brak eis no tre leased automat ically,
re lease theelectr icpar king brak emanuall y(/ page16 0).
If it is still no tpossible torelease theelectr icpar king brak e: #
Donotcon tinue driving under anycir cums tances. Consu ltaqu alif ied spec ialistwo rkshop. 44
2
Dis play messa gesand warning/ indic ator lam ps