engine overheat MERCEDES-BENZ GL SUV 2012 Owners Manual

boostin
geffect. Yo uwill require considerably
more effor ttosteer and brake. There is arisk
of an accident.
Do not switch off the ignition while driving. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause afire
R lose its hold func tion.
There is arisk of fire and an accident .Release
the parking brak efully before driving off.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only set the automatic transmission to the
respective drive positions when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. Othe rwise, you could damage the
drive train.
! AMG vehicles: at low engine oil temper-
atures (below +20 †), the maximum
engine speed is restricted in order to pro-
tec tthe engine. To protec tthe engin eand
maintain smoo thengine operation ,avoid
driving at full throttle when th eengine is
cold. Key positions
Key g
To remove the key
1 Power supply for some consumers, such
as the windscreen wipers
2 Ignition (power supply for all consumers)
and drive position
3 To start the engine
i If the key doe snot belong to the vehicle,
it can still be tur nedint he ignition lock.
However ,the ignition will not be switched
on. The engin ecannot be started.
KEYLESS-GO General notes
R
Do not keep the KEYLESS-GO key together
with:
- electronic devices, e.g. amobile phone
or anothe rkey
- metallic objects, e.g. coins or metal film
- metallic objects, e.g. ametal case
This can affect the fun ction of the key with
KEYL ESS-GO.
Do not keep the KEYLESS-GO key in the tem-
perature-controlled cup holder
(Y pag e347). Othe rwise, the KEYL ESS-GO
key will not be dete cted.
Vehicles with KEYLESS-GO are equipped with
ak ey featuri ngan integrated KEYLESS-GO
function and adetachable Start /Stopbutton. Driving
159Drivingand parking Z

effect, the driv
ewheels coul dlose their grip.
This inc reases the risk of skidding and having
an accident.
Do not shift down for additional engine brak-
ing on aslippery road surface.
Downhill gradients Do not depress the brake pedal continuously
while the vehicle is in motion ,e.g. causing the
brakes to rub by constantly applying light
pressure to the pedal. This results in exces-
sive and premature wear to the brake pads.
On long and steep downhil lgradients, you
mus tselect shift range 1,2or 3in good time.
Take particular not eofthis when drivin ga
laden vehicle.
i This also applies if you have activated
cruise control, SPEEDTRONIC or DIS-
TRONIC PLUS.
This will use the brakin geffect of the engine,
so les sbraking wil lberequired to prevent the
vehicle from gainin gspeed. This relieves the
load on the brak esystem and prevents the
brakes from overheating and wearing too
quickly.
Heavy and light loads G
WARNING
The braking syste mcan overheat if you leave
your foot on the brake pedal while driving.
This increases the braking distance and could
even cause the braking system to fail. There
is ar isk of an accident.
Never use the brake pedal as afootrest .Do
not simultaneousl ydepress both th ebrake
peda land the accelerato rpedal while driving.
! Depressing the brak epedal constantly
result sinexcessive and premature wear to
the brake pads.
If the brakes have bee nsubjected to aheavy
load, do not stop the vehicle immediately.
Driv eonfor as hort while. This allow sthe air-
flo wtoc ool the brakes mor equickly. If the brakes have been used only moderately,
you should occasionally test their effective-
ness. To do this, brake more firmly from a
higher speed. This improves the grip of the
brakes.
Wet road surfaces
If you have driven for
along tim einheavy rain
without braking ,there ma ybeadelayed reac-
tion from the brakes when braking for the first
time. This may also occu rafter acar wash or
after driving through deep water.
You then have to depress the brake pedal
more firmly. Maintain agreater distance from
th ev ehicle in front.
Af terd riving on awet road or havin gthe vehi-
cle washed, brake firml ywhile paying atten-
tion to the traf ficc onditions. This will warm
up the brake discs, thereby dryin gthem more
quickly and protecting them against corro-
sion.
Limited braking performanc eonsalt-
treated roads If you drive on salte
droads, alaye rofs alt
residue may form on the brake discs and
brake pads. This can result in asignificantly
longer brakin gdistance.
R Brake occasionally to remov eany possible
salt residue. Make sure that you do not
endanger other road users whe ndoing so.
R Carefully depress the brake pedal and the
beginning and end of ajourney.
R Maintain agreater distance to th evehicle
ahead.
New brak epads/linings New and replace
dbrake pads and discs only
reach thei roptimum braking effect after sev-
eral hundred kilometres of driving. Compen-
sate for this by applying greater force to the
brak epedal.
For safet yreasons, Mercedes-Ben zrecom-
mends that you only have brak epads/linings
fitted to your vehicle which have been Driving tips
185Driving and parking Z

in effect achieved in the process reduces
the stoppin gdistanc ewhen drivin goff-
road. Th esteerabilit yofthe vehi cleisc on-
siderably redu cedift he wheels lock. Driving systems
Cruise cont
rol
Important safety notes G
WARNING
Do not change down for additional engine
braking on aslipper yroad surface. This could
cause the driv ewheels to lose their grip and
the vehi clec ould skid. G
WAR
NING
Cruise control cannot tak eaccount of road
and traffic conditions.
Alway spay attention to traffic conditions
even when cruis econtrol is activa ted.
Cruise control is only an aid designed to assist
driving. You are responsible for the vehicle's
speed and for braking in good time. G
WAR
NING
Do not use cruise control
R in traffic conditions that do not allow you to
drive at aconstan tspeed (e.g. heavy tra ffic
or winding roads). You may otherwise
cause an accident.
R on slippery roads. The drive wheels may
lose their grip when brakin goraccelerating
and the vehicle may skid.
R whe nther eisl ow visibility ,e.g. due to fog,
heavy rain or snow.
General notes Cruis
econtr ol maintains aconstan troad
speed for you. It brakes automatically in order
to avoid exceeding the set speed. On long and
steep downhil lgradients, especiall yifthe
vehicle is laden or towing atrailer, yo umust
select shift range 1,2or 3in good time. By doing so, you will make use of the braking
effec
tofthe engine. This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly.
Use cruise con trolonly if road and traffic con-
ditions make it appropriate to maintain a
steady speed for aprolonged period. Yo ucan
store any road spee dabove 30 km/h.
Cruise contro llever :
To activate or increase speed
; LIMi ndicato rlamp
= To activate at the current speed/last
stored speed
? To activate or reduce speed
A To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate cruise control
You can operate cruise control and variable
SPEEDTRONIC with the cruise control lever.
X To switch between variable SPEED-
TRONIC and cruise control: press the
cruise control lever in the direction of arrow
A.
LIM indicator lamp ;on the cruise control
lever indicates which function you have selec-
ted:
R LIM indicator lamp ; off:
cruise control
is selected.
R LIM indicator lamp ; on:
variable
SPEEDTRONIC is selected.
When you activate cruise control, the stored
spee diss hown in the multifunction display Driving systems
193Driving and parking Z

SPEEDTRONIC
Important safety notes G
WARNING
Never depress the brake peda lcontinuously
while the vehicle is in motion, e.g. never cause
the brakes to rub by applying constant slight
pedal pressure. This causes the brake system
to overheat, increases the brakin gdistance
and can lead to the brakes failing completely. G
WARNING
Do not change down for additional engine
braking on aslippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid. G
WARNING
SPEEDTRONI Cisonly an aid designe dto
assis tdriving. Yo uare responsibl efor the
vehicle' sspeed and for braking in good time. G
WARNING
If there is achange of drivers, advise the new
driver of the limit speed stored.
Only use variable SPE EDTRONI Cifyou will not
have to accelerate suddenl ytoaspeed above
that stored as the limit speed. You could oth-
erwise cause an accident.
You can only exceed the limit speed stored if
you deactivate variable SPE EDTRONIC:
R using the cruise control lever
R by depressin gthe accelerator pedal
beyon dthe pressure point (kickdown)
It is not possible to deactivate variable
SPE EDTRONI Cbybraking.
General notes SPE
EDTRONIC brakes automatically so that
you do not exceed the set speed. On long and
steep downhil lgradients ,especially if the
vehicle is laden or towing atrailer, yo umust
select shift range 1,2or 3in good time. By
doing so, you will make use of the braking
effect of the engine. This relieves the load on the brake system and prevent
sthe brakes
from overheating and wearing too quickly .If
you need additional braking, depres sthe
brake pedal repeatedly rather than con tinu-
ously.
You can set avariable or permanent limit
speed:
R variable for speedlimits, e.g. in built-up
areas
R permanent for long-term speed restric-
tions, e.g. when drivin gwith winter tyres
fitted (Y page 198)
i The speed indicated in the speedometer
may differ slightly from the limit speed
stored.
Variable SPEEDTRONIC Cruise control lever
:
To activate or increase speed
; LIMi ndicato rlamp
= To activate at the current speed/last
stored speed
? To activate or reduce speed
A To switch between cruise control or DIS-
TRONIC PLUS and variable SPEEDTRONIC
B To deactivate variable SPEEDTRONIC
With the cruise control lever, you can operate
cruise control or DISTRONIC PLUS and vari-
able SPEEDTRONIC.
X To switch between variable SPEED-
TRONIC and cruise control/DISTRONIC
PLUS: press the cruise control lever in the
direction of arrow A.196
Driving systemsDriving and parking

G
WARNING
DISTRONIC PLUS canno ttake account of road
and traffic conditions. If DISTRONI Cdoes not
recognise or no longer recognises the vehicle
in front, do not activate DISTRONIC or, if it is
alr eady active, deactivate it. This is especially
the case:
R befor ecorners
R on filter lanes
R when changing to alane with faster moving
traffic
R in comple xdriving situations or where lanes
are diverte d,e.g. at roadworks on amotor-
way
DISTRONIC PLU Sotherwise maintains the
current spe ed setbyyou or accelerates up to
the set speed.
DISTRONIC PLU Scannot take account of
weather conditions. Deactivate, or do not
activate, DISTRONI CPLUS:
R if th eroads are slippery, snow-covered or
icy .The wheels coul dlose their grip when
brakin goraccelerating .The vehicle could
star ttos kid.
R if the sensors are dirty or there is poo rvis-
ibility, e.g. due to snow, rain or fog. Dis-
tance control may be impaired.
Always pay attention to traffic conditions
even when DISTRONIC PLU Sisactivate d.
Otherwise, you ma yfail to recognise dangers
in time, caus eanaccident and injure yourself
and others. G
WARNING
DISTRONIC PLUS brake syourvehicle up to a
maximu mof4m /s2
depending on its speed.
This corresponds to approximately 40% of
your vehicle's maximum braking power. You
must als oapply the brakes yourself if this
braking power is not sufficient.
If DISTRONI CPLUS detect sarisk of collision
with avehicle in front, an intermit tent warning
tone sounds. In addition, the ·distance
warning lamp in the instrument cluste rlights
up. Brak etoavoidac ollision. G
WAR
NING
The vehicle can be braked when DISTRONIC
PLUS is activated. For this reason, deactivate
DISTRONIC PLUS if the vehicle is to be set in
motion by othe rmeans (e.g. in acar wash or
by towing).
The radar senso rsystem is switched off auto-
matically in the vicinity of radio teles cope
facilities (Y page 433).
If you want DISTRONIC PLUS to assist you,
the radar sensor syste mmust be activated
(Y page 283 )and operational.
General notes DISTRONIC PLUS regulates the speed and
automati
cally helps you maintain the dis-
tanc etot he vehicle detected in front. DI S-
TRONIC PLU Sbrake sautomatically so that
the set spee disnot exceeded.
On long and steep downhil lgradients, espe-
ciall yifthe vehicle is laden or towing atrailer,
yo um ust select shift range 1,2or 3in good
time. By doing so, you will make use of the
braking effec tofthe engine. This relieves the
load on the brake system and prevents the
brakes from overheating and wearing too
quickly.
If DI STRONIC PLUS detects aslower-moving
vehicle in front ,your vehicle is braked in order
to maintain the preset distance to the vehicle
in front.
If ther eisnov ehicle in front ,DISTRONIC
PLUS operate sinthe sam eway as cruise
control in the spee drange between
30 km/h and 200 km/h. If avehicle is driving
in fron tofyou, DI STRONIC operates in the
speed range betwee n0km/h and
200 km/h.
Do not us eDISTRONIC PLUS on roa dswith
steep gradients. Driving systems
199Drivinga nd parking Z

reasons concerning th
eoperating permit.
This also applie sincountries in which the
permissible maximum speed for vehicle/
trailer combinations is above 100 km/h.
When towing atrailer, your vehicle's handling
characteristics wil lbedifferen tincomparison
to when drivin gwithout atrailer and it will
consume more fuel.
On long and stee pdownhil lgradients ,you
must select shift range 1,2or 3in good time.
i This also applies if you have activated
cruise con trol, SPEEDTRONIC or DI S-
TRONIC PLUS.
This will use the brakin geffect of th eengine,
so les sbraking wil lberequired to prevent the
vehicle from gainin gspeed. This relieves the
load on the brak esystem and prevent sthe
brakes from overheating and wearing too
quickly .Ifyou need additional braking,
depress the brake pedal repeatedly rather
than con tinuously.
Driving tips If the trailer swings from sid
etoside:
X Do not accelerate.
X Do not countersteer.
X Brake if necessary.
R Maintain agreater distance from th evehi-
cle in front than when driving without a
trailer.
R Avoid braking abruptly. If possible, brake
gently at first to allow the trailer to run on.
Then, increase the braking force rapidly.
R The values given for gradient-climbing
capabilities from astandstill refer to sea
level. Whe ndriving in mountainou sareas,
note that th epower outpu tofthe engine,
and consequen tlyt he vehicle' sgradient-
climbing capability ,decrease with increas-
ing altitude. Folding out the ball coupling
G
WARNING
If the ball coupling is not correctly engaged,
the trailer can detach. There is arisk of an
accident.
Always engage the ball coupling as described. G
WARNING
If you release the ball coupling or it does not
engage correctly when folding in, it will swing
out. Within pivoting range of the ball coupling,
there is an increased risk of an accident and
injury.
Only release the ball coupling if the pivoting
range is unobstruc ted. Alway smake sure that
the ball coupling engages when folding in.
! AMG vehicles and vehicles with AMG
bodystyling: remove the cover below the
bumper before you fold out the ball cou-
pling. Otherwise, the ball coupling, the
cover and the bumper could be damaged.
Before you can tow atrailer with your vehicle,
yo um ust fold out the ball coupling.
X Make sure that the vehicle is stationary. X
AMG vehicles and vehicles with AMG
bodystyling: pull down cover :by han-
dle ;in the direction of the arrow until it
is released. Towin
gatrailer
259Driving an dparking Z

Engine
Display messages Possible causes/consequences and
M Solutions
+
Top
up co
olant See
Owner'
sManual Th
ec oolant leve listoo low.
! Avoi dmaking long jour neys with too little coolant in the engine
cooling system. The engin ewill otherwise be damaged.
X Top up th ecoolant ,obser ving the warning note sbefore doing
so (Y page 363).
X If th ecoolant needs toppin gupmoreo ften than usual ,have the
engin ecoolant system checked at aqualified specialist work-
shop. ? The fan motor is faulty.
X
If the coolant temperatur eisbelow 12 0†,you can continue
dri ving to the nearest qualified spe cialist workshop.
X Avoid heav yloads on th eengineasy ou do so, e.g. driving in
mou ntainous terrain and stop-start traffic. ?
Co
olantS topv ehi‐ cle Switch engine
off Th
ec oolant is too hot.
Aw arning ton ealso sounds.
G WARNING
Never driv ewithano verheated engine. Drivi ngwhen your engine
is overheate dcan cause fluids that may have leaked int othe
engin ecompartment to catch fire.
Stea mfromano verheated engine can cause serious burns, which
can occ urjus tbyo pening the bonnet.
There is ariskofi njury.
X Stop the vehicl eimmediately, paying att entio ntor oad and traf-
fic conditions, and switc hoff th eengine.
X Secure the vehicl eagainst rolling away (Y page 181).
X Leave the vehicle and keep asafe distance from the vehicle until
the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 120 †. The engine may
otherwise be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit aqualified specialist
worksho pimmediately.
Unde rnormal operatin gconditions and with the specified coolant
level, the coolant tempera ture mayrise to 120 †. 304
Display messagesOn-board computer and displays

Displa
ymessages Possible causes/consequences and
M Solutions
# The battery is no
tbeing charged.
Aw arning ton ealso sounds.
Possible causes:
R fault yalternator
R torn poly-V-belt
R am alfunction in the elect ronics
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Open the bonnet.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult aqualified specialist workshop.
If the poly-V-belt is OK:
X Visit aqualified specialist workshop. 4
Chec
keng. oil lev. when next
refuelling Th
ee ngine oil level has dropped to the minimum level.
Aw arning ton ealso sounds.
X Chec kthe oil level when nex trefuelling, at the latest
(Y page 362).
X If necessary, top up the engine oil (Y page 362).
X Hav ethe engin echecked at aqualified specialist worksho pif
the engine oil needs topping up more often than usual. 4
Top up wit
h1 litre of engine
oil when next refu‐
elling AM
Gvehicles: the engine oil level is too low.
X Check the oil level when next refuelling, at the latest
(Y page 362).
X If necessary, top up the engine oil (Y page 362).
X Hav ethe engin echecked at aqualified specialist worksho pif
the engine oil needs topping up more often than usual. 8
Reserv
efuel level Th
ef uel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X Refuel at the nearest filling station. C There is only
avery small amount of fuel in the fuel tank.
The auxiliary heatin gcannot be operated.
X Refuel at the nearest filling station without fail. Display messages
305On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
?
The red coolant warn-
ing lam
pcomes on
while the engin eisrun-
ning. The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be mal-
functioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X
Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 181).
X Leave the vehicle and keep asafe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 363).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
under 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialis tworkshop.
X Avoid heav yloads on the engin easyou do so, e.g. driving in
mountainous terrain and stop-star ttraffic. ?
Th
er ed coolan twarn-
ing lamp comes on
while the engine is run-
ning. Awarning tone
also sounds. The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartmen tto
catch fire.
Stea mfrom th eoverh eated engine can als ocaus eserious burns
which can occu rjust by opening the bonnet.
This pose sarisk of injury.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secur ethe vehicle against rolling away (Y page 181).334
Warning and indicator lamps in th
einstru ment clusterOn-board computer and displays

!
Alway suseasuitabl ecoolant mixture,
even in countries where high temperatures
prevail.
Otherwise, the engin ecooling system is not
sufficiently protected from corrosion and
overheating.
! The engin ecooling system is filled with
coolant, which must be renewed after
15 years or after 250,000 kilometres at the
latest.
The coolant is amixtur eofw ater and anti-
freeze/corrosio ninhibitor. It performs the
following tasks:
R anti-corrosio nprotection
R antifreeze protection
R raising th eboiling point
If antifreeze/ corrosion inhibitor is presen tin
the correct concentration, the boil ingp oint of
the coolant during operation will be approx-
imately 13 0†.
The antifreeze/ corrosion inhibitor concentra-
tion in the engin ecooling system should:
R be at least 50%. This will protect the engine
coolin gsystem against freezing down to
approximatel y-37 †.
R not exceed 55% (antifreeze protection
down to -45 †). Hea twill otherwise not be
dissipated as effectively.
If the vehicle has lost coolant, top it up with
equa lamounts of water and antifreeze/cor-
rosio ninhibitor. Mercedes-Benz recom-
mends an antifreeze/corrosion inhibito rcon-
cen trate in accordance with MB Specifica-
tions for Service Products 310.1.
The coolant is checked at every maintenance
interval at aqualified special istworkshop.
i When the vehicle is first delivered ,itisfil-
led with acoolant mixtur ethat ensures
adequate antifreeze and corrosion protec-
tion. Windscreen washe
rsystem an dhead-
lamp cleaning system
Important safety notes G
WARNING
Windscreen washer concentrat eishighly
flammable. If it comes into contact with hot
engine component sorthe exhaust system it
coul dignite. There is arisk of fire and injury.
Make sure that no windscreen washer con-
centrate is spille dnext to the filler neck.
! Only use washer fluid that is suitable for
plastic lamp lenses, e.g. MB SummerFit or
MB WinterFit. Unsuitable washer fluid
could damage the plastic lenses of the
headlamps.
! Do not use distilled or de-ionised water in
the washer fluid reservoir. Otherwise, the
level sensor may be damaged.
! Only the washer fluids SummerFit and
WinterFit can be mixed. Otherwise, the
spraying nozzles could become blocked.
At temperatures above freezing:
X Fill the washer fluid reservoir with amixture
of water and washer fluid, e.g. MB Sum-
merFit.
Mix 1part MB SummerFit to 100 parts water.
At temperatures below freezing:
X Fill the washe rfluid reservoir with amixture
of water and washer fluid, e.g. MB Winter-
Fit.
Adapt the mixin gratio to the outside temper-
ature.
R Down to Ò10 †: mix 1part MB WinterFit to
2p arts water.
R Down to Ò20 †: mix 1part MB WinterFit to
1p art water.
R Down to Ò29 †: mix 2parts MB WinterFit
to 1p art water.
i Add washe rfluid concentrate, e.g. MB
SummerFit or MB WinterFit, to the washer
fluid all year round. 430
Service products and capacitiesTechnical data