Key MERCEDES-BENZ M-Class 2012 W166 Workshop Manual

Smar
tKeypositions
Smar tKey g
Toremove theSmartK ey
1 Power supply forsome consumers, such
as the windshield wipers
2 Ignition (powersupplyforallconsumers)
and drive position
3 Tostart theengine
As soon asthe ignition isswitched on,allthe
indicator lampsinthe instrumen tcluster light
up. Ifan indic atorlamp doesnotgoout after
the engineisstart ed orifit light sup while the
vehic leisin mot ion, see(Ypage 271).
If the SmartKey isin posit ion0in the ignit ion
lock foranext ende dperiod oftim e,itcan no
long erbe turned inthe ignit ionlock .The
steering isthen locked. Tounlock, remove the
SmartK eyand reinsert itinto theignition lock.
The steering islocked whenyouremove the
SmartK eyfrom theignition lock.
X Remove theSmartK eywhen theengine is
switched off.
The starter battery couldotherwise be
discharged.
If you cannot turntheSmartK eyinthe ignition
lock, thestarter battery maynotbecharged
sufficiently.
X Check thestarter battery andrecharge itif
necessary (Ypage 340).
or
X Jump-start thevehicle (Ypage 341). i
The
SmartK eycan beturned inthe
ignition lockeven ifit is not thecorrect
SmartK eyfor the vehicle. Theignition isnot
switched on.The engine cannot bestarted.
KEY LESS-GO General
informat ion
Vehicles withKEYLE SS-GO are equipp edwith
aS martKey featuringanintegrated KEYLESS-
GO function andadetacha bleStart/St op
button.
The Start/St opbutton mustbeinserted inthe
ignitio nlock andtheKEYLESS-GO keymust
be inthe vehicl e.
Pressi ngthe Start/St opbutton severaltimes
in successi oncorrespond sto the differe nt
SmartKey positions inthe ignitio nlock. This
is only thecase ifyou arenot depressing the
brake pedal.
If you depress thebrake pedalandpress the
Start /Stopbutton ,the engine starts
immediately.
The Start /Stopbutton canberemoved from
the ignition lock.Then, youcan insert the
Smart Keyinto theignition lock. i
You
donot have toremove theStart /Stop
button fromtheignition lockwhen you
leave thevehicle. However, youshould
alwa ystake theSmart Keywith youwhen
leaving thevehicle. Thevehicle canbe
start edwith theStart /Stopbutton andthe
electric alequipment canbeoperated while
the Smart Keyisin the vehicle. Driving
139Driving and parking Z

X
Insert Start/S topbutton :into ignition
lock ;. i
When
youinsert Start/S topbutton :
into ignition lock;,thesystem requiresa
detection timeofapp roximately two
seconds beforeyoucan useStart/S top
button :. Start/St
opbutton
= USA only
? Cana daonly
X Positio n0: ifStart/S topbutton :has not
yet been pressed ,this corresponds tothe
SmartKey beingremoved fromtheignition.
X Positio n1: press Start/S topbutton :
once.
You cannow activate thewindshi eld
wip ers, forexampl e. i
If
you press Start/S topbutton :twice
when inthis positio n,the powe rsupply is
deac tivat ed again .
X Pos ition 2(ign ition ):pre ssStart /S top
but ton: twice. i
If
you pressStart /S topbut ton: once
when inthis posi tion and thedriv er'sdoor
is open ,th epower supplyis deac tivat ed
again .
As soo nasthe ignition isswitched on,allthe
indicator lampsinthe instrument clusterlight
up. Ifan indicator lampdoesnotgoout after
the engine isstarted orifit lights upwhile the
vehicle isin motion, see(Ypage 271). Star
ting theengin e
Importa ntsafety notes G
WARNING Inhalation
ofexhaust gasishazardous toyour
health. Allexhaust gascont ains carbon
monoxide (CO),andinhaling itcan cause
unconsciousness andpossible death.
Do not run theengine inconfined areas(such
as agarage) whicharenot properly ventilated.
If you think thatexhaust gasfumes are
entering thevehicle whiledriving, havethe
cause determined andcorrect ed
immediately .Ify ou must driveunder these
condit ions,drive onlywith atleast one
window fullyopen atall times. i
Vehicles
withagasoline engine:the
catalytic converter preheats forupto30
seconds afteracold start.Durin gth is time,
th een gin esoun dmay bediff ere nt.
Aut oma tic trans mission X
Sh ift thetrans mis sion toposi tion P.
The trans mis sion position disp layinthe
mult ifunction disp laysho wsP
(Y page 145). i
You
canalso start theen gin ewhen the
tr ans mis sion isin posi tion N.
St artin gpr ocedu rewith theSm artKey X
To star tag asolineeng ine:turn the
SmartKey toposi tion 3in the ignition lock
(Y pag e139) andrelease itas soon asthe
engine isrunning.
X To start adiesel engine: turnthe
Smar tKey toposit ion2in the ignit ionlock
(Y page 139).
The % preglow indicatorlamp inthe
inst rumen tcluster lightsup.
X When the% preglo windic atorlamp
goes out,turnthe SmartK eytoposition 3
(Y page 139)andrelease itas soon asthe
engine isrunning. 140
DrivingDriving and parking

i
You
canstartthe engine without preglow
if the engine iswarm. i
You
canalso usethetouch-st artfunct ion.
To do this, turntheSmartK eytoposition 3
(Y page 139)andrelease itimmediately.
The engine thenstarts automatically .
Using KEYLESS-GO tostar tthe eng ine G
WARNING As
long asthe SmartKey isin you rvehicle, the
vehicle canbestart ed.Therefor e,never leave
children unattended inthe vehicle, asthey
could otherwiseacciden tallystart theengine.
When leaving thevehicle, alwaystake the
Smart Keywith youand lock thevehicle. Do
not leave children unattended inthe vehicle,
or with access toan unlock edvehicle. A
child's unsupervised accesstoavehicle could
result inan acciden tand/o rserious personal
injury. i
The
Start/ Stop button canbeused to
start thevehicle without insertingthe
Smart Keyintothe ignition lock.TheStart/
St op button mustbeinsert edinto the
ignition lockandtheSmart Keymust bein
the vehicle.
X Depress thebrake pedalandkeep it
depressed.
X To star tag asolineeng ine:press the
Start/Stop button(Ypag e139) once.
The engine starts.
X To start adiesel engine: presstheStart/
St op butt on(Ypage 139)onc e.
Preglow isact ivated andtheengin estar ts. Pulling
away
Autom atic transm ission G
WARN
ING It
is danger oustoshift theautomat ic
tr ansm ission outofparkin gposition Por
neutral position Nifthe engine speedis higher
thanidlespeed. Ifyour footisnot firmly
on the brake pedal, thevehicle could
accelerate quicklyforward orinreverse. You
could losecontrolofthe vehicle andhit
someone orsomethin g.Only shiftintogear
when theengine isidling normally andwhen
your right footisfirmly onthe brake pedal. i
It
is only possible toshift thetrans mission
from position Pto the desired position if
you depress thebrake pedal. Onlythenis
the parking lockreleased. Ifyou donot
depress thebrake pedal, youcan move the
DIRECT SELECT lever buttheparking lock
remains engaged.
X Depress thebrake pedalandkeep it
depressed.
X Shift thetrans mission toposition Dor R
(Y page 144).
X Relea sethe brake pedal.
X Carefully depresstheaccelerator pedal.
The electric parking brake(Ypage 156)is
automatically released.
The redF (USAonly)or! (Canada
only) indicator lampinthe instr ument
cluster goesout. i
The
vehicle lockscentrally once youhave
pulled away.The locking knobsinthe doors
drop down.
You canopen thedoors fromtheinside at
any time.
You canalso deactivate theautomatic
locking feature(Ypage 235). i
Upshifts
takeplace athigher engine
speeds afteracold start. Thishelps the
catalytic convertertoreach itsoperating
temperature morequickly.
Pulling awaywithatra iler To
ensure thatyoudonot rollbackwards
when pullingaway onanuphill slope, engage
the electric parking brake. Driving
141Driving and parking Z

X
Press andhold handle :.
The electr icparking brakecontinues to
brake andprevent thevehicle fromrolling
backwards.
The redF (USAonly)or! (Canada
only) indicator lampinthe instrument
cluster remains lit.
X Depress theaccelerator pedal.
X As soon asthe vehicle/t railercombinat ion
is held bythe driving forceofthe engine,
release lever:.
The electr icparking brakeisreleased.
The redF (USAonly)or! (Canada
only) indicator lampinthe instrument
cluster goesout.
Hill star tassist Hill
start assist helpsyouwhen pulling away
forwards orinreverse onanuphill gradient.
It holds thevehicle forashort timeafter you
have removed yourfootfrom thebrake pedal.
This gives youenough timetomove yourfoot
from thebrake pedaltothe accelerat orpedal
and depress itbefore thevehicle beginsto
roll. G
WARN
ING Never
leavethevehicle whenitis held byhill
start assist. Afterapproximately onesecon d,
hill start assist willnolonger brakeyour
vehicle anditcould rollaway. X
Take yourfootoffthe brake pedal. i
Onc
eyou have taken yourfootoffthe
brake pedal, thevehicle isheld foraround
one secon d.
X Pull away .
Hill start assist willnotfunc tion if:
R you arepulling awayonalevel roadora
downhill gradient.
R the tran smission isin position N.
R the electr icparking brakeisapplied.
R ES P®
is malfunct ioning. 142
DrivingDriving and parking

Aut
oma tic trans mission Imp
ortant safety notes G
WAR
NING It
is dan gerous toshif tthe automatic
transmission outofparking position Por
neutral position Nifthe engine speedis
higher thanidlespeed. Ifyour footisnot firmly
on the brake pedal, thevehicle could
accelerate quicklyforward orinreverse. You
could losecontrolofthe vehicle andhit
someone orsomething. Onlyshiftintogear
when theengine isidling normally andwhen
your right footisfirmly onthe brake pedal. G
WARNING Keep
inmind thatturning offthe engine alone
only willshift theautomatic transmission into
neutral position Nautomatically .
Always shifttheautomatic transmission into
park position Pbefore turning offthe engine.
Otherwise thevehicle couldrollaway which
could result inan accident and/orserious
personal injury. DIREC
TSELECT lever
Over view oftrans mis sion positions The
DIRECT SELECT leve rison the right ofthe
steering column. P
Park position withparking lock
R Reverse gear
N Neutral
D Drive i
The
DIRECT SELECTlever alwaysreturns
to its original position. Thecurrent
transmission positionP,R, Nor Dappea rs
in the transmission positiondisplay
(Y page 145)inthe multifunction display.
Engagin gpar kposit ionP X
Push theDI RECT SELECT lever inthe
direc tiono farrow P. i
The
automatic transmissi onshifts
au tomatical lyinto park position Pifyou
open thedrive r'sdoor when thevehicl eis
stationary ordrivi ngatvery lowspee d,and
the transmissi onisin posi tion Dor R.
! Ifthe engine speedis too high orthe
vehicl eis moving, donot shift the
au tomatic transmissi ondire ctly from Dto
R, from Rto Dor dire ctly toP.T he
automatic transmission couldotherwise be
damaged.
Engaging parkposit ionPau tom atically Park
positionPis autom atically engaged if:
R you switchoff theeng ineusin gth e
Sm artKey and remove theSm artKey, orif
you switchoff theeng ineusin gth eSt art /
St op butt onand open oneof thefron t
door s.
R theHOL Dfun ction (Ypage 179)or
DI STRO NICPLUS(Y page 169)brak es
your vehicle untilit is statio naryand atleast
on eof thefollo wing condition sis fulf illed:
- there isasyst emmalf unction.
- there isasev ere uphill ordown hillslope .
The electric park ingbrak eis then also
applied.
Engag ingreversegear R !
Onlyshif tthe automatic transmission to
R when thevehicle isstationary. 144
Automat
ictransmissionDriving and parking

X
When thevehicle isstat ionary, depress the
brake pedal.
X Push theDIRE CTSELECT leveruppast the
first point ofresistan ce.
Shift ingtoneutr alN X
When thevehicle isstat ionary, depress the
brake pedal.
X Push theDIRE CTSELECT leverupordown
to the first point ofresistan ce.
If the engine hasbeen switched off,the
automatic transmission automatic ally
switches toN.
Rema ininginneutr alN
If the automatic transmission isto remain in
neutr alN, e.g. forwashing thevehicle incar
washes withatowing device, pleaseobserve
the following instruct ions: G
WARN
ING When
leaving theSmart Keyinthe start er
switch, donot leave children unattended in
the vehicle. Itis possible forchildren toswitch
on the ignition whichcouldresult in
unsupervised useofvehicle equipment.
Unsuperv iseduseofvehicle equipment could
result inan accident and/orserious personal
injury.
Using theSma rtKey:
R make surethattheignition isswitched on.
R when thevehicle isstat ionary, depress the
brake pedalandkeep itdepressed.
R shift toneutr alN.
R release thebrake pedal.
R ifapplied, releasetheelectr icparking
brake.
R switch offthe ignition andleave the
Smart Keyinthe ignition lock.
Using KEYLESS-GO:
R make surethattheignition isswitched on.
R when thevehicle isstat ionary, depress the
brake pedalandkeep itdepressed.
R engage parkposition P. R
release thebrake pedal.
R remove theStart/ Stop button fromthe
ignition lock.
R insert theSmart Keyinto theignition lock.
R switch onthe ignition .
R depress thebrake pedalandkeep it
depressed.
R shift toneutr alN.
R release thebrake pedal.
R ifapplied, releasetheelectr icparking
brake.
R switch offthe ignition andleave the
Smart Keyinthe ignition lock.
Shift ingtotransmission positionD X
When thevehicle isstat ionary, depress the
brake pedal.
X Push theDIRE CTSELECT leverdown past
the first point ofresistan ce. Tr
ansmission positiondisplay
The curren ttransmis sionposition isshow nin
the multifu nctio ndisplay. :
Tran smiss ionposit ion
The arrows inthe transm ission position
display showhowandintowhich
tr ansm ission positionsyoucan chan geusing
the DIRECT SELECT lever .
! Ifthe transm ission positiondisplay inthe
mult ifunc tiondisplay isnot work ing,you
should pullaway carefully tochec kwhether
the desired transmission positionis
engaged. Selecttransmission positionD.
Do not restrict theshift range. Automat
ictransmission
145Driving and parking Z

Trans
mission pos ition s B
Park
position
Do not shiftthe transmi ssion into
po sitio nP(Y page 155) unless the
veh icleis sta tionar y.The parking
lo ck sho uld not beused asabra ke
wh en parking .In additio nto
eng aging the parking lock, you
mu stalwa ysapplythe electri c
pa rking braketosec urethe
veh icle.
If the vehicleelectro nicsare
ma lfunctio ning,the transmi ssion
ma ybe locked inpo sitio nP. Hav e
the vehicleelectro nicschecked at
a qu alifi ed speci alistw orkshop,
e.g. anauthorized Mercedes-B enz
Center, immediately.
The automatic transmission shifts
to Pautomatically ifyou:
R remove theSmart Key
R switch offthe engine wheninR
or Dand open oneofthe front
doors C
Reverse
gear
Only shiftthetrans mission toR
when thevehicle isstation ary. A
Neut
ral
Do not shift thetrans mission toN
while driving. Otherwise, the
automatic transmission couldbe
damaged.
No power istrans mittedfrom the
engine tothe drive wheels.
Releasi ngthe brakes willallow you
to move thevehicle freely,e.g.to
push itor tow it.
If ESP ®
is deactivated orfaulty:
only shift thetrans mission to
position Nifthe vehicle isin danger
of skidding, e.g.onicy roads.
If you switch offthe engine using
the Smart Keyorthe Start /Stop
button ,the automatic transmission
shifts toneutral Nautomatically.
! Rolling inneutral Ncan damage
the drive train. 7
Drive
The
automatic transmission
changes gearautomatically. All
forward gearsareavaila ble. Changing
gear
The automatic transmission shiftstothe
individual gearsautomatically whenitis in
trans mission position D.Thisautomatic
gearshifting behaviorisdetermined by:
R apossible limitation ofthe shift range
R the position ofthe accelerator pedal
R the road speed 146
Automat
ictransmissionDriving and parking

Gasoli
ne
Fuel grade !
You shou ldonly refuel withpremiu m-
grade unleadedgaso line, asthis avoids
dama gingthecataly ticconverter.
Flexibl efuel vehicle s,identifi ablefrom the
lab elinside thefuel filler flap ,can be
refuel edwith E85. Forfurther information
on flexib lefuel ,see "Fue l".
If engine running problemsareapparent,
have thecause checked immediatelyand
repa ired. Excess unburned fuelcan
otherwi seenter thecataly ticconverter,
lea ding tooverhea tingandpossi bly
causi ngafire.
! Use afilter when refuelingfrom afuel can.
Otherwi se,the fuel lines and/or injection
system couldbeblocked byparticl esfrom
the fuel can. i
Only
refuel withpremiu m-grade unleaded
gaso linewith aspecifi edminimu moctane
numb erof91 (avera gevalue of96 RON/
86 MON) .
You willus ua lly find informa tion abou tthe
fuel grade onthe pump. Ifyou cannot find
the label onthe pump, askthestaff for
assistance.
You canfind more information under"Fuel"
(Y page 385), orby cont acting an
authorized Mercedes-Ben zService Center
or visitin ghtt p://ww w.mbu sa.com (USA
only). Diesel
Fuel grade !
Only refuel withULTRA- LOWSULFUR
DIE SELFUE L(ULSD ,15 ppm SULF UR
MAXI MUM). Usingotherdiesel fuelscould
result inincr eased wearanddamage tothe
engin eand/or exhaust system.
Never refuelwithmarine dieselorheating
oil. Do
not mix these fuelswithdiesel fuelsand
do not use anyspecial additives, asthis
may result indamage.
! Use afilter when adding fuelfrom afuel
can. Other wise, thefuel lines and/or the
fuel inject ion system couldbeblocked by
particles fromthefuel can. i
Usually,
youwillfind infor mation about
the fuel grade onthe pump. Ifyou cann ot
find thelabel onthe gasoline pump,askthe
gas stationstaff .
You canfind more information under“Fuel”
(Y page 385),or by con tact ingan
authoriz edMercedes- BenzService Center
or visitin ghtt p://ww w.mbu sa.com (USA
only).
Low outsid etem pera tures !
Donot use gasoline torefuel vehicles with
a diesel engine.Never mixdiesel with
gasoline orkeros ene,asthis may result in
damage tothe engin eor fuel system.
Diesel fuelwith improved coldflowpropert ies
is available duringthewinter months.Furt her
infor mation onfuel propert iescan be
obtained fromoilcompan ies,e.g. atgas
stat ions. Refueling
Fuel filler flap The
fuel filler flapisunlock edorlocked
automatic allywhen youopen orclose the
vehicle withtheSmart Keyorusing KEYLE SS-
GO.
The position ofthe fuel filler capisdisplayed
in the instrument cluster8.T hearrow
next tothe filling pump indicates theside of
the vehicle. 150
RefuelingDriving and parking

:
Toopen thefuel filler flap
; Toinsert thefuel filler cap
= Fuel type
? Tire pressure table
Opening X
Switc hoff the engine.
X Remove theSmart Keyfrom theignition
lock.
KEYLE SS-GO: open thedriver’s door.This
switches theignition toposition 0,which
correspon dstohaving removed the
Smart Key.Thedriver’s doorcanbeclosed
again.
X Press thefuel filler flapinthe direction of
arrow :.
The fuel filler flapswings up.
X Turn thefuel filler capcount er-clockwise
and remove it.
X Insert thefuel filler capinto theholder
bracket onthe inside offiller flap;.
X Completely insertthepump nozzleinto the
filler neck andrefuel.
X Only fillthe tank untilthepump nozzle
switches off.
! Overfilling thefuel tank could damage the
fuel system. Closing X
Replace thefuel filler capand turn it
clock wise. Thefuel filler capaudibl y
engages.
X Close thefuel filler flap. i
If
you drive withthefuel filler capopen,
reserve fuelwarning lamp8 flashes. In
addition, the; Check Engine warning
lamp maylight up.Am essage appears in
the multifunc tiondisplay (Ypage 257).
For furth erinfor mation onwarning and
indicat orlamps inthe instrument cluster,
see (Ypage 276). Refueling
151Driving and parking Z

Problems
withfuelandthefuel tank Problem Possible
causes/co nsequences andM Solutions
Fuel
isleaking fromthe
vehicle. G
Risk
ofexplosion orfire The
fuel lineorthe fuel tank isdefective.
X Turn theSmartK eytoposition 0(Ypage 139)inthe ignition lock
immediately andremove it.
X Do not restart theengine underanycircumst ances.
X Consult aqual ified specialist workshop. The
fuel filler flap
cannot beopened. The
fuel filler flapisnot unlocked.
or
The SmartK eybattery isdischarged.
X Unlock thevehicle (Ypage 72).
or
X Unlock thevehicle usingthemechanical key(Ypage 75). The
fuel filler flapisunlocked, buttheopening mechanism is
jammed.
X Consult aqual ified specialist workshop. The
engine willnot
start. The
fuel tank ofavehicle withadiesel engine hasbeen run
completely dry.
X Refuel thevehicle withatleast 5.3USqt(5liters) ofdiesel.
X Turn theignition onfor atleast 10seconds (Ypage 139).
X Start theengine continuously forupto10 seconds untilitruns
smoothly.
If the engine doesnotstart:
X Turn theignition onagain forapproximately 10seconds
(Y page 139).
X Start theengine againcontinuously forupto10 seconds until
it runs smoothly.
If the engine doesnotstart after three attempt s:
X Consult aqual ified specialist workshop. DEF
Import antnotes onuse To
funct ionproperly, BlueTECexhaustgas
aftert reatment mustbeoperated withthe
reducing agentDEF. When
theDEFs upply hasalmo strun out,th e Che
ckAdditiveSee Operator's Man
ual mes
sage issho wninthe
mult ifunction disp lay.
When theDE Fs upply sinks toamin imum
leve l,th e Rem
aining Starts:16 mes
sage
is sho wninthemult ifunction disp lay. 152
Ref
uelin gDriving and parking