workshop MERCEDES-BENZ M-Class 2012 W166 Owner's Manual

hard,
donot overload it.And, alwayswear
your seatbelts atall times. Inarollover crash,
an unbelted personissignificantly morelikely
to die than aperson wearing aseat belt. Operat
ingsafety Safety
notes G
WARNING Work
improperly carriedoutonelectronic
componen tsand associated softwarecould
cause themtocease functioning. Because the
vehicle's electronic componentsare
interc onnec ted,anymodifications mademay
produce anundesired effectonother
systems. Electronicmalfunctions could
seriously impairtheoperating safetyofyour
vehicle.
Contact anauthorized Mercedes-Ben zCent er
for repairs ormodificat ionstoelectr onic
compon ents.
Other improper workormodificat ionsonthe
vehicle couldalsohave anegativ eimpact on
the operatin gsafety ofthe vehicle.
Some safety systems onlyfunction when the
engine isrunn ing.You should thereforenever
turn offthe engine whiledriving. G
WARN
ING Heavy
blowsagainst thevehicle underbody or
tires/ wheels maycause serious damage and
impair theoperatin gsafety ofyour vehicle.
Such blows canbecaused, forexample, by
runn ingover anobstacle, roaddebris ora
pothole.
If you feel asudden significantvibration or
ride disturbanc e,or you suspect thatdamage
to your vehicle hasoccurr ed:
R turn onyour hazard warning flashers.
R slow down carefully.
R drive withcaution toan area which isasafe
distanc efrom theroad.
Inspec tthe vehicle underbody andtires/
wheels forpossible damage. Ifthe vehicle appea
rsunsafe, haveittowed tothe nearest
authorized Mercedes-Ben zCent eror other
qualified maintenanc eor repair facility for
furth erinspect ionorrepairs. On-boar
ddiagnost icinter face G
WARN
ING If
you connectequipmen tto the on-board
diagnos ticsint erfac e,itcan affec tthe
operat ionofthe vehic lesyste ms.This can
impair theoperat ingsafet yofyour vehicle
while driving. Thereisarisk ofaccident .
Do not conn ectany equipment tothe on-
board diagnostics interface. G
WARNING Loose
equipment orequipment cableswhich
are conn ected tothe on-board diagnostics
interf acecan obstruct thearea around the
pedals. Theequipment orthe cables couldget
between thepedals inthe event ofsudden
braking oracceleration. Youmay then no
longer beable tobrake, operate theclutch or
accelerate asinten ded.There isarisk of
accident .
Do not attach anyequipment orcables inthe
driver footwell.
Connect ingequipment tothe on-board
diagnostics interfacecan lead toemissions
monit oringinformat ionbeing reset. Thismay
lead tothe vehicle failingtomeet the
requirements atthe next special emissions
test ormain inspect ion.
If the engine isswitched offand equipment
on the on-board diagnostic interfaceisused,
the start erbattery maydischarge.
The on-board diagnostics interfaceisonly
inten dedforthe conn ection ofdiagnostic
equipment ataquali fiedspecialist workshop. 24
Introdu
ction

Qualified
specialist workshop
An authorized Mercedes-BenzCenter isa
qualified specialist workshop. Ithas the
neces saryspecialist knowledge, toolsand
qualifications tocorr ectlycarry outthework
required onyour vehicle. Thisisespecially the
case forwork relevant tosafety.
Observe thenotesinthe service booklet.
Always havethefollowing workcarried outat
an authorized Mercedes-BenzCenter :
R work relevant tosafety
R service andmainten ancework
R repair work
R alteration s,inst allation workand
modificat ions
R work onelectr oniccompon ents Proper
use G
WARNIN
G There
arevarious warning stickersaffixed to
your vehicle. Theirpurpose isto alert youand
others tovarious dangers. Therefore, donot
remove anywarning stickersunless the
stick erclearly statesthatyoumay doso.
If you remove anywarning stickers,youor
others couldfailtorecogn izecert aindangers
and beinjured. G
WARNIN
G HYBRID
vehicles: Itis imperative thatyouread
the HYBRID Supplement alOperatin g
Inst ruction sincluded inyour vehicle literature
portf olio. Youmay otherwise notreceive all
neces sarysafety informationandwarning for
the operation ofyour vehicle.
The proper useofthe vehicle requires that
you familiarize yourselfwiththefollowing
inform ationandrules:
R safety notesinthis Operator' sManual
R tec hnical datainthis Operator' sManual R
traff icrules andregulations
R laws andsafety standards pertainingto
motor vehicles Problems
withyour vehicle
If you should experien ceap roble mwithyour
vehic le,part icularly onethat youbelieve may
affec tits safe opera tion,we urge youto
conta ctan autho rized Merce des-Be nzCenter
im med iatel yto have the problem diag nos ed
and rectified. Ifthe problem isnot resolved to
yo ur satis factio n,plea se discu ssthe problem
ag ainw ithaMerc edes- BenzCent eror
con tact usatone ofthe following addresses.
In the USA Customer
AssistanceCenter
Mercedes- BenzUSA ,LLC
One Mercedes Drive
Mont vale, NJ076 45-035 0
In Canada Customer
RelationsDepartment
Mercedes- BenzCanad a,Inc.
98 Van derh oofAvenue
Tor onto,On tarioM4G 4C9 Rep
orting malfunct ions releva ntto
saf ety
For theUS Aon ly:
The followin gte xt isrepr oduc edasrequi red
of all man ufacturers according toTitle49 ,
Code ofU.S. Fed eral Regulat ions,Part 575
purs uant totheNat ionalTraf ficand Motor
Veh icle SafetyAc tof 19 66.
Rep orting safety defects If
you believ eth at your vehicle has adef ect
whic hco uld caus eacr ash orcould caus e
inj ury ordeat h,you should imm ediat ely
inf orm theNat ionalHig hway TrafficSaf ety Int
rod uction
25 Z

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). Occupant
safety Overview
ofoccupant safety
In this section, youwilllearn themost
import antfactsabout therest raint system
compo nentsof the vehicle.
The restraint system consists of:
R seat belts
R child restraint system s
R LATCH -type (ISOF IX)child seatanchors
Addit ional protection isprovided by:
R SRS (Supplemen talRestrain tSyst em)
R PRE -SAF E®
R Airb ag syst emcompo nentsw ith:
- PAS SENGER AIRB AG OFF indicator lamp
- fro nt-pa ssenge rseat with Occupant
Classification System(OCS)
The differen tairbag systems work
indep endently of each other.The protective
func tionsof the syst emwork incon junction
with each other.Not allair bags aredeployed
in an acc ident . G
WARN
ING Modif
ications toor work impro perly
con duct edon rest raint systemcom pone nts
or the irwirin g,as well astam perin gwith
int erc onn ectedelect ronicsyst ems, canlead to
the rest raint systems nolong erfunc tioning
as intende d.
Air bags orEm ergen cyTens ionin gDev ices
(ETD s),for exam ple,could deploy
inadv ertent lyor fail todeploy inacc ident s
altho ughthedecele ration threshold forair
bag deploymen tisexceeded. Therefore,
never modify therestraint systems. Donot
tamper withelectronic component sor their
software. i
See
"Children inthe vehicle"
(Y page 54)formore information on
infants andchildren traveling withyouin
the vehicle andrestraints forinfants and
children. SRS
(Supplemental RestraintSystem)
Introduction SRS
consists of:
R the 6 SRSwarning lamp
R air bags
R air bag cont rolunit (with crash sensors)
R Emergenc yTensioning Devicesforthe
front seatbelts andtheouter seatbelts in
the rear
R belt force limiters
SRS reduces therisk ofoccupants coming
into contactwith thevehicle's interiorinthe
event ofan accident. Itcan also reduce the
effect ofthe forces towhich occupants are
subjected duringanaccident.
SRS warning lamp SRS
function sare checked regularlywhen
you switch onthe ignition andwhen the
engine isrunning. Therefore, malfunctions
can bedetected ingood time.
The 6 SRSwarning lampinthe instrument
cluster lightsupwhen theignition isswitched
on. Itgoes outnolater thanafew seconds
after theengine isstarted. 38
Occ
upant safetySafety

R
to cros sing traffic
R in cur ves
As ares ult, BAS PLUScann otinte rvenein
cri tica lsi tua tions. The reisaris ko fan
acc iden t.Always paycareful attent ion tothe
tr aff icsit uatio nand berea dytobra ke.
Fol lowi ng dama getothe front endofthe
veh icle, ha ve the confi guratio na nd opera tion
of the rada rs ensor schec kedataqualified
specialist workshop.This also applies to
collisions atlow speeds wherethereis no
visible damage tothe fron tofthe vehicle.
If BAS PLUS isnot availa bledue toa
malfunction inthe radar sensor system, the
brake system remains availablewith full
brake boosting effectandBAS. ESP
®
(Ele ctronic Stability Program)
Import antsafety notes i
See
the"Important safetynotes" section
(Y page 61).
If ESP ®
detect sthat thevehicle isdeviating
from thedirection desiredbythe driver, one
or more wheels arebraked tostabilize the
vehicle. Ifnecessary, theengine outputisalso
modified tokeep thevehicle onthe desired
course withinphysical limits.ESP®
assists
the driver whenpullingaway onwet or
slippery roads.ESP®
can also stabilize the
vehicle duringbraking.
If ESP ®
interven es,the ÷ ESP®
warning
lamp flashes inthe instrumen tcluster . G
WARN
ING Und
erno circums tances should you
deact ivateES P®
when the÷ ESP®
warnin glamp inthe instrumen tclust er
flashe s.Proc eedasfollows :
R when drivingoff ,apply aslittlethr ottleas
possible .
R while driving,ease upon the accelerat or
pedal.
R adapt yourspeed tosuit theprev ailing road
and weathe rconditions .
Failure toobserve theseguidelines could
cause thevehicle toskid. ESP®
cann ot
prevent accident sresulting fromexcessive
speed.
! Only operate thevehicle foramaximum
of ten seconds onabrake test
dynamometer. Switchoffthe ignition.
Application ofthe brakes byESP ®
may
otherwise destroythebrake system.
! Funct ionorperformanc etest smay only
be performed ona2-axle dynamometer. If
you wish tooperate thevehicle onsuch a
dynamometer, pleaseconsult an
authorized Mercedes-B enzCenter
beforehand. Youcould otherwise damage
the drive trainorthe brake system. i
Only
usewheels withtherecommen ded
tire sizes. OnlythenwillESP ®
funct ion
properly.
4ETS (Electronic Traction System) i
Observe
the"Important safetynotes"
section (Ypage 61).
Traction controlispart ofESP ®
.
Traction controlbrakes thedrive wheels
individuall yif they spin. Thisenables youto
pull away andaccelerate onslippery surfaces,
for example ifthe road surface isslippery on
one side. Inaddition, moredrivetorque is
trans ferred tothe wheel orwheels with
tract ion. Driving
safetysystems
63Safety Z

G
WARNING PRE-SAFE
®
Brake cannot alwaysdetect
comple xtraffic situations prope rly.
In these cases, PRE-SAFE(R) Brakemay:
R give anunnecessa rywarni ngand then
brake thevehicl e
R neither giveawarni ngnor intervene
There isarisk ofan accide nt.Alwa yspay
particu larattention tothe traffic situationand
be read yto brake, especiallyif PRE-SAFE(R)
Brake warns you.Termina tethe intervention
in anon-critical drivingsitua tion.
In particu lar,the detection ofobstacl escan
be impa iredifthere is:
R dirt onthe sensors oranythi ngelse
covering thesensors
R snow orheavy rain
R interference byother radarsources
R the possibility ofstron gradar reflect ions,
for example inparking garages
R anarrow vehicle traveling infront ,e.g. a
motorbik e
R avehicle traveling infront onadifferent line G
WARNIN
G PRE-S
AFE®
Brake doesnotreact:
R to people oranimals
R to oncom ingvehicles
R to crossin gtraffic
R in curves
As aresult, PRE-SAFE®
Brake cannot
interv eneincritic alsituations. Thereisarisk
of an accident .Always paycaref ulatt ent ion
to the traffic situat ionand beready tobrak e.
In order tomaint ainthe appropr iatedistance
to the vehic lein fro ntand thus preventa
collisio n,you must apply thebrak esyourself .X
To act ivat e/deact ivate:act ivate or
deact ivatePRE-SAFE®
Brak ein the on-
board computer (Ypage 232).
The Ä symbol appears inthe
multif unction display aslong asthe HOL D
func tion isnot activate d(Ypage 179).
On vehicles withActive Parkin gAssist ,the
Ä symbol isdisplayed when
tran smission positionPis select edorifyou
drive faster than22mph(35 km/h).
For PRE-S AFE®
Brak eto assist youwhen
drivin g,the radar senso rsyst em mus tbe
switched on(Ypage 236)andoperational.
Following damagetothe front endofthe
vehicle, havetheconfiguration andoperation
of the radar sensors checked ataqual ified
speciali stworkshop. Thisalso appli esto
collisions atlow speeds wherethereisno
visible damage tothe front ofthe vehicle. STEER
CONTROL
The steering assistant STEERCONTROL helps
you bytransmitt inganoticeable steering
force tothe steering wheelinthe direction
required forvehicle stabilization.
This steering assistance isprovided in
particular if:
R both right wheels orboth leftwheels areon
a wet orslippe ryroad surface whenyou
brake
R the vehicle startstoskid
You have controlover thesteering atall
times. G
WARNING If
the ESP ®
is malfunctioning, youwillnot
receive steering assistance fromtheSTEE R
CONTROL. Thepower steering function,
however, remainsavailable. Driving
safetysystems
67Safety Z

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). Sma
rtKey Impor
tant safet ynotes G
WARN
ING When
leaving thevehicle, alwaysremovethe
Smart Keyfrom theignit ionlock .Always take
the Smart Keywith youand lock thevehicle.
Do not leave children unsuperv isedinthe
vehicle, evenifthey aresecured inachild
rest raint system ,and donot give them acces s
to an unlock edvehicle. Achild's unsupervised
access toavehicle couldresult inan accident
and/or serious personal injury.Theycould:
R injure themselves onvehicle parts
R be seriously orfatally injured byextrem e
heat orcold
R injure themselves orhave anaccident with
vehicle equipment thatmay stillbein
operation evenaftertheSmartKey has
been removed fromtheignition, suchasthe
seat adjustment ,steering wheel
adjustment ormemory function.
If children openadoor, theycould cause
severe oreven fatalinjury toother persons; if
they getout ofthe vehicle, theycould injure
themselves whendoing soorbe seriously or
even fatally injured byany passing traffic.
Do not expose thechild restraint systemto
direct sunlight. Thechild restraint system's
metal parts, forexample, couldbecome very hot,
andachild could beburned onthese
parts. G
WARNING If
akey ring istoo heavy ortoo large, the
weight actingonthe key could cause itto turn
in the ignition lockorcatch onthe steering
wheel. Thiscould cause theengine tobe
switched offsuddenly. Youcould losecontrol
of the vehicle andcause anaccident. Donot
attach anyheavy orlarge keyrings tothe key
that isinserted inthe ignition. General
notes
If you cannot lockorunlock thevehicle with
the SmartK ey,either thebattery inthe
SmartK eyisdischarged, theSmartK eyis
faulty orthe starter battery isdischarged.
X Check thebattery inthe SmartK eyand
replace itifnecessary (Ypage 76).
X Unlock thedriver's doorusing the
mechanical key(Ypage 80).
X Lock thevehicle usingthemechanical key
(Y page 80).
X Have thestarter battery andthebattery
cont acts check edataqual ified specialist
workshop.
If the SmartK eyisfaulty, contactRoadsi de
Assistanc eor aqual ified specialist workshop. Smar
tKeyfunctions
General notes i
USA
only:
This device complies withPart15ofthe
FCC Rules. Operation issubject tothe
following twocondition s:
1. This device maynotcause harmful
interfer ence,and
2. this device mustaccept anyinterfer ence
received, includinginterferencethatmay
cause undesired operation. 72
Smar
tKeyOpening/closing

The
KEYLE SS-GO funct ionischanged as
follows:
X To unlock thedriver 'sdoor: touch the
inner surface ofthe door handle onthe
driver's door.
X To unlock centrally: touchtheinner
surface ofthe door handle onthe fron t-
passenger doororthe rear door.
X To lock centrally: touchtheouter sensor
surface onone ofthe door handles. Restoring
thefactor ysettings
X Press the% and& button s
simultaneously forapproximately six
seconds untilthebattery checklamp
flashes twice. Mechanical
key
General notes If
the vehicle cannolonger beunlocked with
the Smart Key,usethemechanic alkey.
If you usethemechanic alkey tounlock and
open thedriver's door,theanti- theft alarm
system willbetriggered (Ypage 68).
There areseveral waystoturn offthe alarm:
X To turnthe alarmoff with the
Smar tKey: pressthe% or& button
on the Smart Key.
or
X Insert theSmart Keyinto theignition lock.
or
X To deactivat ethe alarmwith KEYL ESS-
GO: press theStart/S topbutton inthe
ignition lock.TheSmart Keymust beinthe
vehicle.
or
X Lock orunlock thevehicle usingKEYLE SS-
GO. TheSmart Keymust beoutside the
vehicle. Removing
themechanical key X
Push release catch: inthe direction of
the arrow andatthe same time,remove
mechanic alkey ;from theSmart Key. Smar
tKeybattery
Impor tantsafety notes Have
thebatteries changedataquali fied
specialist workshop. G
WARNIN
G Batt
eries containtoxicsubstances .
Swallowing batteriescanlead toserious
health issues ordeath.
Keep batteries outofthe reach ofchildren.
Seek medical attentionimmediately ifa
battery isswallowed . G
WARNIN
G The
Smart Keybatteries containperchlorate
material, whichmayrequire specialhandling
and regard forthe environ ment.Observe
governm entdisposal guidelines. California
resident s,see www .dtsc.ca.gov/
Haza rdousW aste/Perchlora te/
index.cfm. Sma
rtKey
75Opening/closing Z

Check
ingthebat tery X
Pre ssthe& or% button.
The battery iswork ingproperl yif bat tery
ch eck lamp :light sup brie fly
If bat tery check lamp :does notlight up
brief lydurin gthe test,the batt eryis
disch arged.
X Changin gthe batt ery(Ypage 76) i
You
canobtain the batt eryataqualified
spec ialist workshop. i
If
the SmartKey batteryischec kedwithin
the sign alrec eptio nrang eof theveh icle,
pres singth e& or% buttonloc ksor
unlo cksth eveh icle.
Cha nging thebat tery You
requi reaCR 2025 3V cel lbat tery.
X Tak eth emec hanical keyout ofthe
Sm artKey (Ypage 75). X
Pre ssmec hanical key; intoth eopen ing
in theSm artKey inthedire ction ofthe arr
ow untilbat tery tray cover :open s.
When doingso, donoth old cover :shut.
X Remove batterytraycover :. X
Repeatedly tapthe Smart Keyagainst your
palm untilbattery =falls out.
X Insert thenew battery withthepositive
termin alfacing upwards. Usealint- free
cloth todo so.
X Make surethatthesurface ofthe battery is
free from lint,grease andallother forms of
cont amination.
X Insert thefront tabsofbattery tray
cover :and then press toclose it.
X Insert themechanical keyinto the
Smart Key.
X Check thefunct ionofall Smart Keybutton s
on the vehicle. 76
Sma
rtKeyOpening/closing

Problems
withtheSmar tKey Problem Possible
causes/co nsequences andM Solutions
You
cannot lockor
unlock thevehicle
using theSmartK ey. The
SmartK eybattery isdischarged ornearly discharged.
X Try again tolock/un lockthevehicle usingtheremote control
funct ionofthe SmartK ey.Point thetipofthe SmartK eyatthe
driver's doorhandle fromclose range andpress the%/
& button.
If this does notwork:
X Check theSmartK eybattery (Ypage 76)and replace itif
necessary (Ypage 76).
X Lock (Ypage 80)orunlock (Ypage 80)thevehicle using
the mechanical key. The
SmartK eyisfaulty.
X Lock (Ypage 80)orunlock (Ypage 80)thevehicle using
the mechanical key.
X Have theSmartK eycheck edataqual ified specialist workshop. You
cannolonger lock
or unlock thevehicle
using KEYLE SS-GO. There
isinterf erence fromapowerful sourceofradio waves.
X Lock/ unlock thevehicle usingtheremote controlfunct ionof
the SmartK ey.Point thetipofthe SmartK eyatthe driver's door
handle fromclose range andpress the%/& button. There
isamalfunction withKEYLE SS-GO.
X Lock/ unlock thevehicle usingtheremote controlfunct ionof
the SmartK ey.Point thetipofthe SmartK eyatthe driver's door
handle fromclose range andpress the%/& button.
X Have KEYLE SS-GO check edataqual ified specialist workshop.
If this does notwork:
X Check theSmartK eybattery (Ypage 76)and replace itif
necessary (Ypage 76).
X Lock (Ypage 80)orunlock (Ypage 80)thevehicle using
the mechanical key. You
have losta
SmartK ey. X
Have theSmartK eydeactivated ataqual ified specialist
workshop.
X Report theloss immediately tothe vehicle insurers.
X Ifnecessary, havethelocks changed aswell. You
have lostthe
mechanical key. X
Report theloss immediately tothe vehicle insurers.
X Ifnecessary, havethelocks changed aswell. Smar
tKey
77Opening/closing Z

Problem Possible
causes/co nsequences andM Solutions
The
engine cannot be
started usingthe
SmartK ey. The
on-board voltageistoo low.
X Switch offnon- essential consumers, e.g.seat heating orinterior
lighting, andtrytostart theengine again.
If this does notwork:
X Check thestarter battery andcharge itifnecessary
(Y page 338).
or
X Jump-start thevehicle (Ypage 341).
or
X Consult aqual ified specialist workshop. The
engine cannot be
started usingKEYLE SS-
GO. TheSmartK eyisin
the vehicle. Ad
oor isopen. Therefore, theSmart Keycann otbe detect edas
easily .
X Close thedoor andtrytostart thevehicle again. There
isinter ferenc efrom apowerful sourceofradio waves.
X Start yourvehicle withtheSmart Keyinthe ignition lock. Doors
Import
antsafety notes G
WARNIN
G When
leaving thevehicle, alwaysremove the
Smart Keyfrom theignition lock.Always take
the Smart Keywith youand lock thevehicle.
Do not leave children unsupervised inthe
vehicle, evenifthey aresecured inachild
restraint system,anddonot give them access
to an unlocked vehicle.Achild's unsupervised
access toavehicle couldresult inan accident
and/or serious personal injury.Theycould:
R injure themselves onvehicle parts
R be seriously orfatally injured byextrem e
heat orcold
R injure themselves orhave anaccident with
vehicle equipment thatmay stillbein
operation evenaftertheSmartKey has
been removed fromtheignition, suchasthe
seat adjustment ,steering wheel
adjustment ormemory function. If
children openadoor, theycould cause
severe oreven fatalinjury toother persons; if
they getout ofthe vehicle, theycould injure
themselves whendoing soorbe seriously or
even fatally injured byany passing traffic.
Do not expose thechild restraint systemto
direct sunlight. Thechild restraint system's
metal parts, forexample, couldbecome very
hot, andachild could beburned onthese
parts. G
WARNING Do
not carry heavy orhard object sin the
passenger compartmen tor cargo
compartmen tunle ssthey arefirmly secu red
in place .
Unse curedorimp roperlypo sitio ned cargo
incre ases achi ld's ris kof inju ryinthe event
of
R stro ngbra king maneu vers
R sudd en cha nges ofdirecti on
R an acci dent 78
Do
orsOpening/closing