2012 MERCEDES-BENZ M-Class top up coolant

norm
aland notasign tha tther eis a
ma lfunctio n. i
The
cooling with aird ehumidification
func tion uses refriger antR134a. This
coolant doesnotcontain
chlorof luorocarbon s,and therefore does
not damage theozon elayer.
Activating/d eactivating X
To activa te:press the¿/Á button.
The indicat orlamp inthe ¿/Á
button lightsup.
X To deactiva te:press the¿/Á
button .
The indicat orlamp inthe ¿/Á
button goesout.Thecooling withair
dehumidification function hasadelayed
switch -offfeature.
Problems withthecooling withair
dehum idificat ionfunction When
youpress the¿/Á button,the
indicat orlamp inthe button flashes three
times orremains off.You cannolonger switch
on the cooling withairdehumidification
func tion.
X Consult aqualified specialist workshop. Sett
ingclimat econtrol toaut omat ic G
WARN
ING If
you switch offthe cooling function,the
vehicle willnotbecooled whenweather
con ditions arewarm. Thewindows canfogup
more quickly. Window foggingmayimpair
visibility andendanger youand other s.
In automatic mode,thesettemper atureis
maint ained automatic allyatacon stan tlevel.
The system automatic allyregulates the
temper atureofthe dispensed air,the airflow
and theairdistribut ion.
Autom aticmode willachieve optimal
operation ifcooling withairdehumidification is
also activat ed.Ifdesired, coolingwithair
dehumidification canbedeactivat ed.
In the rear compart ment,you can also switch
climate control forthe rear seats toautomatic
mode usingtheà button .
X Turn theSmart Keytoposition 2in the
ignition lock.
X Set thedesired temperature.
X To activa te:press theà button .
The indicat orlamp inthe à button lights
up. Autom aticairdistribut ionand airflow
are activ ated. i
Autom
aticclimate control: when
automatic modeisactivat ed,you can
select aclimate modesetting
(Y page 129).
X To switch off:press the_ button .
or
X Press theI orK button .
The indicat orlamp inthe à button goes
out. Adju
sting theclimat emode settings
(AIR FLOW)
This function isonly available withautomatic
climate control.
The climate control settings areespecially
effec tiveathigh temper atures.
You canselect thefollowing climatecontrol
sett ings inautomatic mode:
FOCUS highairflow thatisset slightly
cooler
MED IUM medium airflow,standard setting
DIF FUS Elow airflow thatisset slightly
warmer andwith alower rateof
airflow Opera
tingtheclimate controlsystem
129Climate control Z

Problems
withtheengine Problem Possible
causes/co nsequences andM Solutions
The
engine doesnot
start. Thestarter motor
can beheard. R
There isamalfunction inthe engine electron ics.
R There isamalfunction inthe fuel supply .
X Try tostart theengine again(Ypage 140). Avoid excessively
long andfrequent attemptsto start theengine asthese willdrain
the battery.
If the engine doesnotstart after several attempt s:
X Consult aqual ified specialist workshop, e.g.anauthorized
Mercedes-B enzCenter. The
engine doesnot
start. Youcannot hear
the starter motor. The
on-board voltageistoo low because thebattery istoo weak
or discharged.
X Jump-start thevehicle (Ypage 341).
If the engine doesnotstart despite attemptsto jump-st artit:
X Consult aqual ified specialist workshop, e.g.anauthorized
Mercedes-B enzCenter. The
starter motorwasexposed toathermal loadthatwastoohigh.
X Allow thestarter motortocool down forapproximately two
minutes.
X Try tostart theengine again.
If the engine stilldoes notstart:
X Consult aqual ified specialist workshop, e.g.anauthorized
Mercedes-B enzCenter. The
engine isnot
running smoothly and
is misfiring. There
isamalfunction inthe engine electron icsoramechanical
componen tof the engine management system.
X Only depress theaccelerator pedalslightly.
X Have thecause rectifiedimmediately ataqual ified specialist
workshop, e.g.anauthorized Mercedes-B enzCenter.
Otherwise, non-combusted fuelmay getinto thecatalytic
conv erter anddamage it. The
coolant
temperature gauge
shows avalue above
248 ‡(120 †). The
coolant levelistoo low. Thecoolant istoo hotand theengine
is no longer beingcooled sufficiently.
X Stop assoon aspossible andallow theengine andthecoolant
to cool down.
X Check thecoolant level(Ypage 315). Observe thewarning
notes asyou dosoand add coolant ifnecessary. Driving
143Driving and parking Z

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

!
Ifthe coolant temperature istoo high a
displa ymessage isshown.
If the coolant temperature risesabove
248 ‡(120 †),donot drive anyfurther as
this could damage theengine. Tachometer
The redband inthe tachometer indicatesthe
engine's overrevving range.
! Donot drive inthe overrevving range,as
this could damage theengine.
The fuel suppl yis interrupted toprotect the
engine whenthered band isreached. Outside
tempera turedisplay
The outside temperature displayis in the
multifunction display(Y page 224). G
WARNING The
outside temperature indicatorisnot
designed toserve asan ice-warning device
and istherefore unsuitablefor that purpose.
Indicated temperatures justabove the
freezing pointdonot guara nteethattheroad
surface isfree ofice. The road maystillbeicy,
especial lyin wooded areasoron bridges.
Changes inthe outside temperature are
displa yedafter ashort delay. Speedometer
withsegments
The segments inthe speedometer indicate
which speed rangeisavail able.
Cruise control(Ypage 167)activated:
The segments lightupfrom thestored speed
to the maximum speed.
DISTRONIC PLUS(Ypage 169)activated:
One ortwo segments inthe setspeed range
light up.
DISTRONIC PLUSdetects avehicle infront :The
segments betweenthespeed ofthe
vehicle infront andthestored speedlightup. Operating
theon-board computer
Overview The
on-board computer isactivated assoon
as you turn theSmartKey toposition 1in the
ignition lock.
You cancont rolthe multifunction displayand
the settings inthe on-board computer using
the buttons onthe multifunction steering
wheel. :
Multifunction display
; Toswitch onthe Voice Control System;
see theseparate operating instructions
= Right controlpanel
? Left controlpanel
A Back button Dis
plays andoperation
223On-board computer and displays Z

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

Problem Possible
causes/co nsequences andM Solutions
8
The
yello wreserve fuel
warning lamplights up
while theengine is
running. The
fuel level hasdropped intothereserve range.
X Refuel atthe nearest gasstation. ?
The
redcoolant
warning lamplights up
while theengine is
running andthecoolant
temperature gaugeis
at the start ofthe scale. The
temperature sensorforthe coolant temperature gaugeis
defective.
The coolant temperature isno longer beingmonitor ed.There isa
risk ofengine damage ifthe coolant temperature istoo high.
X Pull over andstop thevehicle safelyandswitch offthe engine,
payi ngatten tiontoroad andtraffic condition s.Do not cont inue
driving underanycircumst ances.
X Apply theelectric parking brake.
X Consult aqual ified specialist workshop. War
ning andindicator lampsin the instrum entcluster
277On-board computer and displays Z

Problem Possible
causes/co nsequences andM Solutions
?
The
redcoolant
warning lampcomes on
while theengine is
running. The
coolant levelistoo low.
If the coolant leveliscorrec t,the airflow tothe engine radiator
may beblocked orthe electric engineradiator fanmay be
malfunction ing.
The coolant istoo hotand theengine isno longer beingcooled
sufficiently.
X Observe theadditional displaymessages inthe multifunct ion
display .
X Pull over andstop thevehicle safelyandswitch offthe engine,
payi ngatten tiontoroad andtraffic condition s.
X Allow theengine andcoolant tocool.
X Check thecoolant levelandadd coolant (Ypage 315). Observe
the warning notes.
X Ifyou need toadd coolant moreoften thanusual,have the
engine coolant systemchecked.
X Make surethattheairsupply tothe engine radiator isnot
blocked, e.g.bysnow, slushorice.
X At coolant temperatures under248‡(120 †),drive tothe next
qualified specialist workshop.
X Avo idsubjec tingthe engin etoheavy loads, e.g.driving in
mountainous terrain,andstop- and-go traffic. ?
The
redcoolant
warning lampcomes on
while theengine is
runnin g.Awarning tone
also sounds. The
coolant temperat urehas exceeded 248‡(120 †).The
airflow tothe engine radiator maybeblocked orthe coolant level
may betoo low.
The engine isnot being cooled sufficient lyand may bedamaged.
X Observe theadditional displaymessages inthe multifunct ion
display .
X Pull over andstop thevehicle safelyandswitch offthe engine,
paying attentiontoroad andtraffic conditions.
X Allow theengine andcoolant tocool.
X Check thecoolant levelandadd coolant (Ypage 315). Observe
the warning notes.
X Ifyou need toadd coolant moreoften thanusual ,have the
en gin eco olan tsyst em checke d.
X Mak esur eth at theair supp lyto theen gin eradi ator isno t
bloc ked, e.g. by snow, slushor ice .
X At coolan ttemperatures under248‡(120 †),drive tothe next
qualified specialist workshop.
X Avo idsubjec tingthe engin etoheavy loads, e.g.driving in
mountainous terrain,andstop- and-go traffic. 278
War
ning andindicator lampsin the instru mentclusterOn-board computer and displays

G
WARNING Driving
whenyourengi ne isove rheatedcan causesom efluids which mayhave leaked intothe
engin ecom partmen ttocatch fire.Youcould beseriously burned.
Steam fromanoverheated enginecancause serious burnswhich canoccur justbyopening the
engine hood.Stayaway fromtheengine ifyou seeorhear steam coming fromit.
Stop thevehicle inasafe location awayfromother traffic.Turn offthe engine, getout ofthe
vehicle anddonot stand nearthevehicle untiltheengine hascooled down.
! Ifthe coolant temperature exceeds248‡(120 †)donot cont inue driving. Theengine will
otherwise bedamaged. Driving
systems Problem Possible
causes/cons equencesandM Solutions
·
The
reddistance
warning lamplights up
while thevehicle isin
motion .A warning tone
also sounds. G
Risk
ofaccident The
warning isissued ifyou approach astation aryvehicle ora
vehicle drivingaheadofyou attoo high aspeed.
X Be prepared tobrake immediately.
X Pay careful attentiontothe traffic situation. Youmay have to
brake ortake evasive action.
More informat ionabout DISTRONIC PLUS(Ypage 169)and
PRE-S AFE®
Brake (Ypage 65). War
ning andindicator lampsin the instru mentcluster
279On-board computer and displays Z