2012 MERCEDES-BENZ GL SUV towing

R
uphill or downhill gradien tinpercentage
R on-road/off-road program selected
R condition of the differential lock for the
transfer case
R the LOW RANGE off -road gear is selected
R condition of the LOW RANGE off -road
gear
R the on-roa dtrailer progra misselected Towing
atrailer Note
sont owingatrailer
Important safety notes G
WARNING
Veh icle sw ithl evel control:
Th ev ehicle level can be change dinadver-
tently, e.g. whe nchanged by anot her person.
If yo uare coupling up or uncoupling atrailer
when this happens ,you coul dbecom etrap-
ped. Bod yparts can also become trapped
between the vehicle body and tyres, or under-
neath the vehicle. This pose sarisk of injury.
When coupling up or uncoupling, make sure
that no-one:
R opens or closes the doors or tailgate
R initiates the level control or presses the
AD Ss witch
R locks or unlock sthe vehicle. G
WARNING
The brakin gsystem can overheat if you leave
your foot on the brake pedal while driving.
This increase sthe brakin gdistanc eand could
even cause the braking system to fail. There
is ar isk of an accident.
Never use the brake pedal as afootrest. Do
not simultaneously depress both the brake
pedal and the accelera torp edal while driving. G
WAR
NING
You could los econtrol of the vehicle/trailer
combination if it begins to swerve. The vehi- cle/
trailer combination could even overturn.
There is arisk of an accident.
On no account should you attempt to
straighten out the vehicle/trailer combina-
tion by increasing speed. Decrease your
speed and do not countersteer .Brake if nec-
essary. G
WARNING
If you excee dthe permissible noseweight
while carrying aload, the carrier system could
detac hfrom th evehicle and fall on the road.
There is arisk of an acciden tand injury.
Always maintain the permissible noseweight
whe ncarrying loads. G
WARNING
If the ball coupling is not correctly engaged ,it
coul ddetac hwhile drivin gand fall on the road.
There is arisk of an acciden tand injury.
Engag ethe ball coupling as described. G
WARNING
If the ball coupling is not cor rectly engaged,
the traile rcan detach. There is arisk of an
accident.
Always engage the ball coupling as described.
! Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
You can use carrier systems, e.g. bicycle
rack sorload-bearing implements, on the ball
coupling. The maximum noseweight of
75 kg applies when using carrier system son
the ball coupling.
Whe nreversin gthe vehicle towards the
trailer ,make sure there is nobody between
the trailer and the vehicle.
Couple and uncouple the trailer carefully. If
you do not couple the trailer to the towing
vehicle correctly, the trailer could become
detached. Towin
gatrailer
257Driving an dparking Z

Make sur
ethat the followin gvalues are not
exceeded:
R the permissible trailer drawba rnoseweight
R the permissible trailer load
R the permissible rea raxle load of the towing
vehicle
R the maximum permissible gros svehicle
weight of both the towing vehicle and the
trailer
The applicable permissible values, which
must not be exceeded, can be found:
R in the vehicle documents
R on the identification plates of the trailer tow
hitch, the trailer and the vehicle
If the values differ, the lowest value applies.
You will fin dthe values approved by the man-
ufacturer on the vehicle identification plates
and those for the towing vehicle under "Tech-
nical data "(Ypage 433).
When towing atrailer, your vehicle's handling
characteristics wil lbedifferent in comparison
to when drivin gwithout atrailer.
Th ev ehicle/ trailer combination:
R is heavier
R is restricted in its acceleration and gradi-
ent-climbin gcapability
R has an increased braking distance
R is affected more by stron gcrosswinds
R demand smore sensitive steering
R has alarger turnin gcircle
This could impair the handling charac teris-
tics. Adapt your styl eofdriving accordingly.
Maintain asafe distance. Drive carefully.
When towing atrailer, alw aysa djust your
speed to the current road and weather con-
ditions. Do not exceed the maximum permis-
sible speed for your vehicle/trailer combina-
tion.
General notes !
Use adrawbar noseweigh tasc lose as
possible to the maximum permissible nose-
weight. Do not use anoseweight of less than 50kg, otherwise the trailer ma
ycome
loose.
Not ethat the payload and the rea raxle load
are reduce dbythe actual payload.
i Chec kthe tyr epressures when towin ga
trailer. You will find the values in the tyre
pressure table in the fuel filler flap of the
vehicle (Y page 399).
You will find installation dimensions and loads
in the "Technical data" section
(Y page 432).
The maximum permissible trailer drawbar
noseweight on the ball coupling is 140 kg.
However, the actual noseweight must not
exceed the value given on the trailer tow hitch
or trailer identification plates .The lowest
weight applies.
Please not ethat when towing atrailer, PARK-
TRONIC (Y page 216) and Blind Spo tAssist
(Y page 238) ar eonly available with limita-
tions ,orn ot at all.
Driving tips i
Observ ethe information on ESP ®
trailer
stabilisation (Y page 67)and on pulling
away with atrailer. (Y page 162).
Vehicle swith the ON&OFFROAD pack-
age: select the trailer program (Y page 250)
with the off- road program selector wheel in
the centre console.
The maximum permissible spee dfor vehicle/
trailer combina tions depends on the type of
trailer .Befor ebeginning the journey, check
the trailer's document stosee what the max-
imu mpermitted speed is. Observ ethe legally
prescribed maximum speed in the relevant
country.
For cer tain Mercedes-Benz vehicles, the max-
imum permissible rear axle load is increased
when towing atrailer. See "Technica ldata" to
find out whethe rthis applies to your vehicle
(Y page 433). If you utilise any of the added
maximum rea raxle load whe ntowing atrailer,
th ev ehicle/ trailer combination may not
exceed amaximum spee dof100 km/h for 258
Towin
gatrailerDriving an dparking

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

X
AMG vehicles and vehicles with AMG
bodystyling: release cover =from the
bracket at the rea rand sto witsafely. X
Open the tailgate.
X Pull release knob :until the ball coupling
unlocks.
The ball coupling folds out from under the
rear bumper.
The indicator lamp on the release knob
flashes .The trailer socket folds away auto-
matically. X
Press the ball couplin ginthe direction of
the arrow until it engages in avertical posi-
tion.
The indicator lam ponthe release knob
goes off.
The multifunction display shows the
Chec ktrailer hitch lock message
until th eball coupling is engaged.
X Remove the protective covering from the
ball coupling and store it in asafe place. Coupling up
atrailer
Important safety notes G
WARNING
Vehicles with level control:
If you disconnec tthe trailer cable, the vehicle
is lowered. This can cause you or other sto
become trapped between the vehicl ebody
and tyres, or underneat hthe vehicle. This
poses arisk of injury.
Make sure that no-on eisinthe immediate
vicinit yofthe wheel arch or underneath the
vehicle when disconnectin gthe trailer cable.
Vehicles with th eAIRMATIC package X
Make sure that the transmission is in posi-
tion P.
X Engage the electric parking brake.
X Start the engine.
X Set the vehicle to highway level
(Y page 213).
X Set the Adaptive Damping System (ADS )to
AUTO orCOMF (Ypage 212).
X Switch off the engine.
X Close the doors and tailgate.
X Position the trailer level behind the vehicle.
X Coupl eupthe trailer.
X Establish the electric con nectio nbetween
the vehicle and the trailer.
X Check that the trailer lighting system is
working. 260
Towing
atrailerDriving an dparking

to position
2or 0respective ly
( Y page 159). Bulb fa
ilure indicato rfor LEDl amps
i If LED lamps ar efitted in the trai ler, an
error message ma yappea rinthe multi-
function display eve nifthere is no fault .The
reason for the err or message could be that
the curren thas fallen below the minimum
of 50 mA.
To ensur ereliable operation of the bulb failure
indicator, each LE Dchain in the trailer lighting
must be guaranteed aminimum curren tof
50 mA. Trailer wit
h7-pin connector
General notes Trailers with 7-pi
nconnector: you can
make aconnection to the 13 -pin connector
on the ball coupling using an adapter plug or,
if necessary, an adapter cable. Bot hcan be
obtained in aqualified specialist workshop.
Fitting the adapter !
Make sure that there is sufficien tcable
play so that the cable cannot become
detached when cor nering.
! Remove th einstalled adapter cable
before folding in the ball coupling. Other-
wise, damage may occur to the rear
bumpe rand the adapter cable. X
Ope nthe socket cover.
X Inser tconnector with lug :into
groove ;of the socket. Tur nthe connec-
tor cloc kwise to the stop.
X Let the cover engage.
X If you are using an adapter cable, secure
the cable to the trailer with cable ties. Towing
atrailer
263Driving an dparking Z

Problems wit
htrailer towing Problem Possible causes/consequences and
M Solutions
The released ball cou-
pling cannot be
engaged. X
Visit aqualified specialist workshop. The ball coupling does
not unlock, even
though:
R
the vehicle is station-
ary
R no trailer cable is
connected
R the release knob to
unlock the ball cou-
pling has been pulled
for more than asec-
ond. The on-boar
dvoltage is insufficient.
X Start the engine.
If the ball coupling still does not unlock:
X Visit aqualified specialist workshop. 264
Towin
gatrailerDriving an dparking

Driving systems
Display messages Possible causes/consequences and
M Solutions
À
At
tention Assist: Tak
eab reak! Base
doncertai ncrite ria, ATTENTION ASSIST ha sdetecte dfatigue
or alack of con centration on the part of the driver. Awarning tone
als os ounds.
X If necessary, tak eabreak.
During long journe ys,take regular breaks in goo dtime so that you
get enoug hrest. À
Attention Assist
inoperative ATTENTION ASSIS
Tisinoperative.
X Visi taq ualifieds pecialist workshop. Á
Please
reduce speed You can
notc hang ethe vehicle level. Possible causes:
R you ar edriving to ofast for the selected vehicle level.
R you are towing atrailer.
R thet railer-coupling socket is being used ,e.g. for abicycle rack.
X Driv emore slowly and then select the desire dvehicle level
again.
R Vehicles with the ON&OFFROA Dpackage (Y page 207)
R Vehicles with the AIRMATI Cpackage (Y page 213)
X Observ ethe notes on towing atrailer (Y page 257). Á
Co
mpressor is cool‐
ing Yo
uh ave selected ahigher vehicle level. The compressor first
needs to cool down because of frequen tlevel changes.
X Driv einam anner appropriate for the curren tvehicle level.
X Make sure that ther eissufficien tground cle arance.
X Allow the compresso rtocool down.
When the compressor has cooled down, the display message
disappears. The vehicle then con tinues rising to the selected
level. Á
Malfunction AIRMATIC is faulty.
X
Drive as appropriate for the current vehicl elevel, but do not
exceed 80 km /h.
X Make sur ethat ther eissufficient ground clearance.
X Have the vehicle checked at aqualified specialist workshop. Display messages
307On-board computer and displays Z

Displa
ymessages Possible causes/consequences and
M Solutions
Vehicles wit
hBecker ®
MA PPILOT :ifthe Becker ®
MA PPILOT is
not connected, the radar sensor syste misdeactivated automati-
cally.
BAS PLUS, DI STRONIC PLUS, Blind Spot Assis torActive Blind
Spo tAssist and PRE-SAFE ®
Brake ar enot available.
X Connect the Bec ker®
MAP PILOT; see the separate operating
inst ructions. Lane Keeping
Assist currently
unavailable See
Owner's Manual
Active Lane Keep‐
ing Assist cur‐
rently unavailable
See Owner's Manual Lane Keeping Assist or Active Lane Keeping Assist is deactivated
and temporarily inoperative. Possibl
ecauses:
R the windscreen is dirty in the camera' sfield of vision.
R visibility is impaired due to heavy rain, snow or fog.
R there are no lane markings for alonger period.
R the lane markings ar eworn ,dark or covered, e.g. by dirt or snow.
When the causes listed above no longer apply ,the displa ymes-
sage goes out.
Lan eKeeping Assist or Active Lan eKeeping Assist is operational
again.
If the display message does not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rollin gaway (Y page 181).
X Clean the windscreen. Lane Keeping
Assist inoperative
Active Lane Keep‐
in
gA ssist inoper‐ ative Lan
eKeeping Assist or Active Lan eKeeping Assist is faulty.
X Visit aqualified specialist workshop. Blin
dSpot Assist currently unavail‐
able See Owner's
Manual
Active Blind Spot
Assist currently
unavailable See
Owner's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inop-
erative.
Yo uh ave established the electrical connection between the trailer
and your vehicle.
X Press aon the steering wheel to confirm the display mes-
sage.
Blind Spot Assis torActive Blind Spo tAssist is deactivate dwhile
towing atrailer. Display messages
311On-boardcompu tera nd displays Z