2012 MERCEDES-BENZ M-Class Check engine

Please
notethat when towing atrailer,
PARKTRONIC (Ypage 183)andBlind Spot
Assist (Ypage 198)areonly availabl ewith
limitations ,or not atall. i
On
vehicles withoutlevelcontrol,the
height ofthe ball coupling willalter
accordin gto the load placed onthe vehicle.
If necess ary,useatrailer withaheight-
adjustable drawbar.
Driving tips i
Observe
theinform ationonESP®
trailer
stabilization (Ypage 64)and onpulling
away withatrailer. (Ypage 141).
The maximum permissible speedforvehicle/
trailer combinat ionsdepends onthe type of
trailer. Before beginnin gthe journ ey,check
the trailer's document sto see what the
maximum permittedspeed is.Observe the
legally prescribed maximumspeedinthe
relevant country.
For cert ainMercedes- Benzvehicles, the
maximum permissible rearaxle load is
incr eased whentowing atrailer. Refertothe
"Technical data"sectiontofind outwhether
this applies toyour vehicle. Ifyou utilize any
of the added maximum rearaxle load when
towing atrailer, thevehicle/t railer
combinat ionmay notexceed amaximum
speed of60 mph(100 km/h)for reasons
conc ernin gthe operating permit.Thisalso
applies incount riesinwhich thepermissible
maximum speedforvehicle/t railer
combinat ionsisabove 60mph(100 km/h).
When towing atrailer, yourvehicle's handling
charact eristics willbedifferen tinc omparison
with when driving without atrail er.
On long andsteep downhill gradients, you
must selectshift range 1,2or 3in good time. i
This
alsoapp liesif you have activated
cruise control orDISTRONIC PLUS.
This willuse thebraking effectofthe engine,
so that lessbraking willbe requ iredto
maintai nthe speed. Thisrelieves theload on
the brake system andprevents thebrakes from
overheating andwearing tooquickly. If
you need additional braking,depressthe
brake pedalrepeatedly ratherthan
cont inuously .
Driving tips R
Maintain agreater distance fromthe
vehicle infront thanwhen driving without a
trailer.
R Avoid braking abruptly. Ifpossible, brake
gently atfirst toallow thetrailer torun on.
Then, increase thebraking forcerapidly .
R The values givenforgradient-c limbing
capabil itiesfrom astandst illrefer tosea
level. When driving inmountainous areas,
note thatthepower output ofthe engine,
and consequent lythe vehicle's gradient-
climbing capability,decrease with
increasing altitude.
If the trailer swings fromsidetoside:
X Do not accelerate.
X Do not counter- steer.
X Brake ifnecessary. Assemblin
gthe ball coupling
! Mercedes-Ben zrecomm endsthatyou
have theball coupling assembled ata
qualified specialist workshop.Only a
qualified specialist workshophas the
nec essary specialist knowledge andtools
to carry outthework required. Youcould
other wiseincorrectlyassemble theball
coupling ortight enthe nut with the
incor recttorque. Thiscould leadtothe ball
coupling andtheball coupling carrier
becomin gdetached whiletowing atrailer.
As aresult, youcould cause anacciden t.
Therefor e,have theball coupling
assembled ataqualified specialist
worksho p.
If the assembled ballcoupling hasbeen
permanen tlymount edon the vehicle, have
the ball coupling regularly checkedfor 212
Tr
ailer towingDriving and parking

G
WARNING Do
not disconnect atrail erwith anengag ed
overru nbrake. Otherwi se,you rhand could
bec ome trapped between thebumpe rand
trai lerd rawb ar.
Observe themaximu mpermissible trailer
dimension s(width andlengt h).
Most federal statesand allCanadian
provin cesrequire bylaw:
R safety chains between thetowing vehicle
and thetrailer. Thechains should becross -
wound underthetrailer drawbar. Theymust
be fasten edtothe vehicle's trailer
coupling, nottothe bumper orthe axle.
Allow forenough playinthe chains to
facilitat eturn ingtight corners.
R aseparate brakesystem forcert aintypes
of trailer.
R asafety switch forbraked trailers. Check
the specific legalrequirement sapplicable
to your federal state.
If the trailer detaches fromthetowing
vehicle, thesafety switch applies the
trailer's brakes.
! Donot connectthe trailer's brakesystem
(if featured) tothe hydrau licbrake system
of the towing vehicle, asthe latter is
equipp edwith ananti-lock brakesystem.
Doing sowill result inaloss offunct ionof
the brake systems ofboth thevehicle and
the trailer.
X Make surethattheautomatic transmission
is set toposition P.
X Apply thevehicle's electricparking brake.
X Start theengine.
X Vehicles withtheAIRMATIC package:
select highway level.
X Vehicles withtheadaptive damping
system: setADS toAUTO orCOMF.
X Switch offthe engine.
X Close alldoors andthetailgate.
X Coupl eup the trailer.
X Est ablish allelectrical connections. i
Vehicles
withtheAIRMATIC package:
if you couple upatrailer, thevehicle always
remains athighway level.When coupling up
a trailer, please observe thefollowing:
R ifhighway levelhasnotbeen set
manually ,the vehicle willautomatically
sink tohighway levelassoon asit
reaches aspeed of5m ph(8km/ h).
R high-spe edlevel isnot available.
These restrictions apply toall access ories
powered through acon nection tothe trailer
power socketofyour vehicle, e.g.abicycle
carrier . Towing
atrail er
Th ere arenum erouslega lreq uirem ents
conce rning the towingofatra iler, e.g.speed
rest rictions. Make surethatyour vehicle/
trailer combin ationcomplies withthelocal
requiremen tsnot only inyour areaof
residen cebut also atany location towhich
you aretrav eling. Thepolice andlocal
authorit iescan provide reliableinformation .
Please observe thefollowing whentowinga
trailer:
R To acquaint yourselfwithdrivin gwith a
trailer andwith theresultin gchang esto
handling, youshould practicecorn ering,
stoppin gand backin gup inatraf fic-free
location .
R Befor edrivin g,chec k:
- the trailer towhitch
- the safety switchfor braked trailers
- the safety chains
- the elect ricalconnection s
- the lights
- the wheels
R Adj ust the exterior mirror sto provide an
unobst ructedview ofthe rear sectionofthe
trailer.
R Ifthe trailer features electronic ally
con trolled brakes, pullaway thevehicle/
trailer combin ationcarefully, manually 216
Tr
ailer towingDriving and parking

brake
usingthebrake controller, andchec k
the brakes forcorr ectfunc tion.
R Sec ureany objec tson the trailer topreven t
the cargo fromslipping whenthevehicle is
in mot ion.
R Ifyou couple upatrailer, regularly check
the cargo forsecure fasteningand make
sure thatthetrailer lamps and(if
applicable) thetrailer brakes are
func tioningcorr ectly.
R Bear inmind thatthehandling willbeless
stable whentowingatrailer thanwhen
drivin gwithout one.Avoid sudden steering
movem ents.
R The vehicle/ trailercombin ationisheavier,
acceler atesmore slowly, hasadecreased
gradient climbingcapability andalonger
brakin gdistan ce.
It is more suscept ibletoside winds and
requires morecareful steering.
R Ifpossible, avoidabrupt braking.Depres s
the brake pedalmoderat elyatfirst ,so that
the trailer canactiv ateitsown brakes. Then
incr ease thepressure onthe brake pedal.
R Ifthe automatic transmission continues to
shift back andforthbetween twogears
when drivingup ordownhill, restrict the
shift range. Selectshiftrange 4,3,2,or 1.
Al ower gearandlower speed reduce the
risk ofengine failure.
R On long andsteep gradients thatare
difficult todrive down inshift range 1,
switch tothe off-road program orengage
the LOW GEAR off-road gear.
R When driving downhill, shifttoalower gear
to utilize theengine's brakingeffect.
Avoid continuous brakeapplication asthis
may overheat thevehicle brakesand,if
installed, thetrailer brakes.
R Ifthe coolant temperat ureincreases
dramatically whiletheair-con ditioning
system isswitched on,switch offthe air-
condit ioning system.
Coolant heatcanadditionally bedissipated
by opening thewindows andbysett ingthe blower
fanand theinterior temperat ureto
maximum.
R When overtak ing,payparticular attention
to the exten dedlength ofyour vehicle/
trailer combinat ion.
Due tothe length ofyour vehicle/t railer
combinat ion,youwillhave totravel an
additional distancebeyondthevehicle you
are overtak ingbefore returningtothe
previous lane. Deco
upling atrail er G
WA
RNI NG Ve
hicle swi th airs uspen sionprogram :While
you arecoupling ordecoupling atrailer, make
sure nobody locksorunlocks thevehicle and/
or opens orcloses doorsorthe tailgate.
The vehicle's levelcould change andyou
could endanger yourselfand/orothersasa
result.
Make surethatyoudonot operate theADS
switch orthe vehicle levelcontrolsystem
when coupling/decoupling thetrailer.
! Donot disconnec ta trailer withan
engaged overrunbrake.Otherwise, your
vehicle couldbedamaged bythe
rebounding ofthe overrun brake.
X Make surethattheautomatic transmission
is set toposition P.
X Apply thevehicle's electricparking brake.
X Start theengine.
X Close alldoors andthetailgate.
X Apply thetrailer's parkingbrake. G
WARNING Vehicles
withairsuspension program:As
soon asyou disconnec tthe electrical
conn ection between thetrailer andthe
vehicle, thevehicle willlower. Tohelp avoid
personal injury,makesurenoone isnear the
wheel housing orunderneath thevehicle
before theelectrical connection is
disconnec ted. Tr
ailer towing
217Driving and parking
Z

When
youdecouple thetrailer, thevehicle is
tempor arilyraised because thesprings are
relieved ofload. Beespecially carefulduring
this process, asyou could otherwise injure
yourself and/orothers.Make sure that any
pers onsrem ainin gin theveh icle donotp ress
the switches forvehicl elevel control orthe
ADS.
X Remo vethe trail ercabl eand decou plethe
trail er.
X Switch offthe engine. Permissi
bletrailer loadsanddrawbar
nos eweig hts
Weig htspec ifications The
gross trailerwei ght iscalcu lated by
add ingthe weight ofthe trail erto the weight
of the loadand equipme nton the trail er.
Maximu mgross vehicl ewei ght: 17
.
The maximu mpermissible trailerdrawbar
noseweight isthe maximum weightwith
which thetrailer drawbar canbeloaded: 17
Threshold forMercedes- Benzapproved
trailer towhitches.
Loading atrail er R
Wh enload ing the trailer, makesure tha t
nei the rthe permissible grossweight ofthe
trailer northegross vehicle weightare
exceeded. Thepermissible grossvehicle
weight isindicated onthe identification
plate onthe B-pillar onthe driver's sideof
the vehicle.
You canfind themaximum permissible
values onthe type plates ofyour vehicle
and thetrailer. Always observe thelowest
respective valuewhen determining the
maximum weightwithwhich youcan load
the vehicle andthetrailer.
R The trailer drawba rload onthe ball coupling
must beadded tothe rear axle load toavoid exceeding
thepermissible grossaxle
weight. Thepermissible grossvehicle
weight isindicated onthe identificat ion
plate onthe B-pillar onthe driver's sideof
the vehicle. i
Mercedes-B
enzrecomm endsloading the
trailer sothat thedrawbar noseweight
remains between 8%and 15% ofthe
permissible grosstrailer weight. i
The
weight ofadditional accessories,
passengers, andcargo reduces the
permissible trailerloadanddrawbar
noseweight foryour vehicle.
Checking thevehicle andtrailer weight R
To check thattheweights ofthe towing
vehicle andthetrailer comply withthe
maximum permissible values,havethe
vehicle/t railercombinat ion(including the
driver, passengers, andcargo withafully
laden trailer) weighed onacalibrated
weighbridge.
R Check thegross axleweight ratingofthe
front andrear axles, thegross weight ofthe
trailer andtrailer drawbar noseweight. Removing
theball coupling
X Remove thespring cotter.
X Remove thebolt from theball coupling
recess.
X Remove theball coupling fromtheball
coupling recess.
X Clean theball coupling ifit is dirty.
Infor mation oncleaning andcare ofthe trailer
tow hitch canbefound at(Y page 322). Storing
theball coupling G
WARNIN
G Do
not carry theball coupling inthe vehicle
interior ifit is not secured.
17 Missing valueswerenotavailabl eattime ofgoing toprin t. 218
Tr
ailer towingDriving and parking

Useful
information
i This
Operat or'sManual describesall
models andallstan dard andoption al
equipment ofyour vehicle available atthe
time ofpublication ofthe Operat or's
Manual. Country-specificdiffer encesare
possible. Pleasenotethat your vehicle may
not beequipped withallfeature s
descr ibed. Thisalso applies tosafet y-
related systemsand func tions. i
Please
readtheinfor mation onqualified
specialist workshops(Ypage 25). Impor
tant safet ynotes You
willfind anillustrat ionofthe instrumen t
clust erinthe "Ataglance" section
(Y page 29). G
WARN
ING A
driver' satt ent ion tothe road andtraffic
con dition smust always behis/her primary
focus whendriving.
For your safetyand thesafet yof other s,
select ingfeature sthr ough themultifun ction
steer ingwheel should onlybedone bythe
driver whentrafficand road condition spermit
it to be done safely.
Bear inmind thatataspeed ofjust 30mph
(approxim ately50km/ h),your vehic leis
cove ringadistan ceof44 feet (approxim ately
14 m)every second. G
WARN
ING No
messages willbedisplayed ifeither the
inst rumen tclust eror the multif unction
display isinoper ative.
As aresult, youwillnotbeable tosee
info rmat ionabout yourdrivin gcon dition s,
such as
R speed
R outside temperatur e
R warnin g/indicato rlamps R
malf unction/ warn ingmes sages
R failur eof any systems
Dr ivin gch arac terist ics may beimpair ed.
If you must continue todriv e,do sowith added
caut ion.Contac tana uth oriz edMer cedes-
Ben zCent eras soon aspossible. G
WARN
ING Malfunct
ionand warning messages areonly
indicat edfor cert ainsystems andare
inten tionally notvery detailed. The
malfunct ionand warning messages are
simply areminder withrespect tothe
operation ofcert ainsystems. Theydonot
replace theowner's and/ordriver's
respons ibilitytomaint ainthe vehicle's
operatin gsafety. Haveallrequired
maint enanc eand safety checksperform edon
the vehicle. Bringthe vehicle toan authorized
Mercedes- BenzCenter toaddress the
malfunct ionand warning messages. Displays
andopera tion Coolant
temperaturedispla y G
WARN
ING Drivin
gwhen yourengine isoverheat edcan
cause somefluidswhich mayhave leaked into
the engine compart menttocatc hfire. You
could beseriously burned.
St eam from anoverheat edengine cancause
serious burnswhich canoccur justbyopening
the engine hood.Stay away fromtheengine
if you seeorhear steam comingfrom it.
St op the vehicle inasafe location awayfrom
other traffic.Turn offthe engine, getout ofthe
vehicle anddonot stand nearthevehicle until
the engine hascooled down.
The coolant temperaturegauge isin the
inst rument clusteronthe right- hand side.
Under normaloperatin gcon ditions andwith
the specified coolantlevel,thecoolant
temper aturemayriseto248 ‡(120 †). 222
Displays
andopera tionOn-board computer and displays

Disp
laymessa ges Poss
iblecauses/c onseq uences and M Solu
tions G
Tel
eAid Ino
perative US
Ao nly:one ormor eof the mainfunctio nsinthe mbr ace system
ar ema lfunctio ning.
Ca nad aonl y:one ormor eof the mainfunctio nsofthe TELEAI D
sy stem arema lfunctio ning.
X USA only:ha ve the mbr ace system checked ataq ualifi ed
spec ialist workshop.
X Canad aon ly: have theTE LE AIDs ystem checke dat aqualif ied
spe cialist wor kshop . PRE
-SAFE Ino
perative See Ope
rator'sMan ual G
Ri
sk ofinjury Im
por tant fun ction sofPRE-SAFE ®
have failed .Alloth erocc upant
safet ysyst ems, e.g.airbags, remain available.
X Visit aqualified specialist workshop immed iately. PRE-
SAFE Func
tion Curr
ently Limi
tedSee Oper. Manu
al G
Risk
ofacciden t PRE-
SAFE®
Br ake istem porar ilyinope rative if:
R the DISTRON ICPLUS coverinthe radiat orgrill isdirt y.
R the sensors inthe bumper sare dirty.
R its func tion isimpaired duetoheavy rainorsno w.
R the radar sensor syst emistem porar ilyinope rative, e.g. due to
elect romagnet icradiat ionemit tedbynear byTV orradio
st ation sor oth ersourc esofelect romagnet icradiat ion.
R the syst emisouts idethe operat ingtem perat urerang e.
R the on-board voltage istoo low.
PRE- SAFE®
Br ake isoperat ionalagain andthedisplay message
disappears if:
R the dirt (e.g.slush) drops awaywhile thevehic leisin mot ion.
R the syst emdete ctsthat thesensors arefully available again.
R the syst emiswithin theoperat ingtem perat urerang e.
If the display messagecontinues tobe displayed:
X Clean theDISTRON ICPLUS coverinthe radiat orgrill
(Y page 322).
X Clean thebumper s(Y page 322).
X Restar tthe engine.
X Wait untilthebattery issufficiently charged. Display
messages
245On-board computer and displays Z

Engine
Displ
aymes sage s Possib
lecau ses/cons equences andM Solu
tions +
Che
ckCoolant Lev
elSee Ope
rator'sMan ual The
coolant levelis toolow.
X Add coolant ,obse rving thewarn ingnoteswhen doingso
(Y page 315).
X Ifcoo lant needs tobe added moreoft en than usual, havethe
en gin ecoo lant systemcheck edataqualifie dspec ialist
work shop. G
WAR
NING Do
notspill antif reeze onhot engin eparts. Antifr eeze contains ethylene glycolwhich mayburn
if it comes intocon tact with hotengin eparts. Youcould beseriously burned.
! The coolant levelistoo low. Avoid makin glong journ eyswith toolittlecoolant inthe cooling
system. Theengin ewill other wisebedamaged.
The display messages andthecorr espondin gsymbol thatindicat ethat thecoolant levelis
too low must notbeignored. 254
Display
messagesOn-board computer and displays

Disp
laymessa ges Poss
iblecauses/c onseq uences and M Solu
tions ?
Coo
lantLev elLow Sto
pVeh icl eTur n Eng
ine Off The
coolan tistoo hot.
X Pull over andstop thevehicle safelyandswitch offthe engine,
pay ing attent iontoroad andtraffic conditions.
X Make surethattheairsuppl yto the engine radiatorisnot
blocked, e.g.bysnow, slushorice.
X Wait untilthedispla ymessage disappearsbefore restarting the
engine. Otherwise, thereisarisk ofengine damage .
X Pay attent iontothe coolant temperature display.
X Ifthe temperature increasesagain,visit aqual ified speciali st
workshop immediately . The
poly-V-belt mayhave torn.
X Pull over andstop thevehicle safelyandswitch offthe engine,
pay ing attent iontoroad andtraffic conditions.
X Open thehood.
X Check whether thepoly-V-belt istorn.
If the poly-V-belt istorn:
! Donot cont inue driving. Theengine couldotherwise overheat.
X Consult aqual ified speciali stworkshop.
If the poly-V-belt isnot dam aged:
X Wait untilthedispla ymessage disappearsbefore restarting the
engine. Otherwise, thereisarisk ofengine damage .
X Pay attent iontothe coolant temperature display.
X Visit aqual ified speciali stworkshop. G
WARNING Driving
whenyourengine isoverheated cancause somefluidswhich mayhave leaked intothe
engine compartment tocatch fire.Youcould beseriously burned.
Steam fromanoverheated enginecancause serious burnswhich canoccur justbyopening the
engine hood.Stayawayfrom theengine ifyou seeorhear steam coming fromit.
Stop thevehicle inasafe location awayfrom other traffic. Turnoffthe engine, getout ofthe
vehicle anddonot stand nearthevehicle untiltheengine hascooled down.
! Ifthe coolant temperature exceeds248‡(120 †)donot cont inue driving. Theengine will
otherwise bedamage d. Dis
play messages
255On-board computer and displays Z