MERCEDES-BENZ GL-Class 2013 X166 Owner's Manual

When towing a trailer, your vehicle's handling
characteristics will be differen tincomparison
with when driving without atrailer.
On long and steep downhill gradients, you
must select shift range 1,2or 3in good time.
i This also applies if you have activated
cruise control or DISTRONIC PLUS.
This will use the braking effect of the engine,
so that less braking will be required to
maintai nthe speed, This relieves the load on
the brake system and prevents the brakes
from overheating and wearing too quickly. If
you need additional braking, depress the
brake pedal repeatedly rather than
continuously.
Driving tips If the trailer swings from side to side:
X
Do not accelerate.
X Do not counter-steer.
X Brake if necessary.
R Maintain a greater distance from the
vehicle 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 a standstill refer to sea
level. When driving in mountainous areas,
note that the power output of the engine
and, consequently, the vehicle's gradient-
climbing capability, decreases with
increasing altitude. Installing the ball coupling
G
WARNING
If the ball coupling is not installed and secured
correctly it can become detached while the
vehicle is in motion and fall onto the road.
There is a risk of accident and injury. Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter.
G
WARNING
If the ball coupling is not installed correctly or
not secured with the bolt provided and the
corresponding spring cotter, the trailer may
come loose. There is a risk of an accident.
Always install and secure the ball coupling as
described. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter. G
WARNING
If the ball coupling is not installed and secured
correctly the trailer may come loose. There is
a risk of an accident.
Install and secure the ball coupling as
described in the ball coupling installation
instructions. Make sure that the ball coupling
is installed and secured correctly before every
journey. Cover cap
X
Pull protective cap 0002in the direction of the
arrow, out of the ball coupling recess.
X Place protective cap 0002in the ball coupling
recess. Towing
atrailer
259Driving an d parking Z

Ball coupling recess
Holes in the ball coupling and ball coupling recess
X
Insert the ball coupling horizontally into ball
coupling recess 0003in the direction of the
arrow until the holes in ball coupling 0021are
in line with the holes in ball coupling
recess 0020. Bolt
X
Slide bolt 001Einto the hole in the ball
coupling recess and the ball coupling to the
stop. Bolt and spring cotter
X
Secure the bol tusing spring cotter 001F. Correctly installed and secured ball coupling
X
Check the ball coupling, bolt and spring
cotter for correct installation.
If the ball coupling cannot be correctly
mounted, remove the ball coupling. Under
these circumstances, the ball coupling must
not be used for trailer towing.
If the ball coupling cannot be locked and the
key cannot be removed, remove the ball
coupling and clean it. If the ball coupling can
still not be installed (locked) after it has been
cleaned, remove the ball coupling. The trailer
tow hitch must then not be used to tow a
trailer, as safe operation cannot be
guaranteed.
Have the entire trailer tow hitch checked at a
qualified specialist workshop. Coupling up a trailer
! Do not connect the trailer's brake system
(if featured) to the hydraulic brake system 260
Towing
atrailerDriving an d parking

of the towing vehicle, as the latter is
equipped with an anti-lock brake system.
Doing so will result in a loss of function of
the brake systems of both the vehicle and
the trailer.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's electric parking brake.
X Start the engine.
X Vehicles with the AIRMATIC package:
select highway level.
X Vehicles with ADS: set ADS toAUTOor
COMF.
X Switch off the engine.
X Close all doors and the tailgate.
X Couple up the trailer.
X Establish all electrical connections.
X Check that the trailer lighting system is
working.
i Vehicles with the AIRMATIC package:
with a trailer attached, the vehicle will
always remain at highway level. When
coupling up a trailer, please observe the
following:
R Unless highway level has been set
manually, the vehicle is automatically
lowered to highway level. This is the case
if a speed of 5mph(8km/h) is reached.
R High-speed level is not available.
These restrictions apply to all accessories
powered through a connectio nto the trailer
power socket of your vehicle, e.g. a bicycle
carrier.
Observe the maximum permissible trailer
dimensions (width and length).
Most U.S. states and all Canadia nprovinces
require by law:
R Safety chains between the towing vehicle
and the trailer. The chains should be cross-
wound under the trailer drawbar. They must
be fastened to the vehicle's trailer
coupling, not to the bumper or the axle. Leave enough play in the chains to make
tight cornering possible.
R As eparate brake system for certain types
of trailer.
R As afety switch for braked trailers. Check
the specific legal requirements applicable
to your state.
If the trailer detaches from the towing
vehicle, the safety switch applies the
trailer's brakes. Towing
atrailer
There are numerous legal requirements
concerning the towing of a trailer, e.g .speed
restrictions. Make sure that your vehicle/
trailer combination complies with the local
requirements not only in your area of
residence but also at any location to which
you are traveling. The police and local
authorities can provide reliable information.
Please observe the following when towing a
trailer:
R To acquaint yourself with driving with a
trailer and with the resulting changes to
handling, you should practice cornering,
stopping and backing up in a traffic-free
location.
R Before driving, check:
-Trailer tow hitch
- Safety switch for braked trailers
- Safety chains
- Electrical connections
- Lights
- the wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer features electronically
controlled brakes, pull away the vehicle/
trailer combination carefully, manually
brake using the brake controller, and check
the brakes for correct function. Towing
atrailer
261Driving an d parking Z

R
Secure any objects on the traile rto prevent
the cargo from slipping when the vehicle is
in motion.
R If you couple up a trailer, regularly check
the cargo for secure fastening and make
sure that the trailer lamps and (if
applicable) the trailer brakes are
functioning correctly.
R Bear in mind that the handling will be less
stable when towing a trailer than when
driving without one. Avoid sudden steering
movements.
R The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, avoid abrupt braking. Depress
the brake pedal moderately at first, so that
the trailer can activate its own brakes. Then
increase the pressure on the brake pedal.
R If the automatic transmission continues to
shift back and forth between two gears
when driving up or downhill, restrict the
shift range. Select shift range 4, 3, 2,or1.
Al ower gear and lower speed reduce the
risk of engine failure.
R When driving downhill, shift to a lower gear
to utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if
installed, the trailer brakes.
R If the coolant temperature increases
dramatically while the air-conditioning
system is switched on, switch off the air-
conditioning system.
Coolant heat can additionally be dissipated
by opening the windows and by setting the
blower fan and the interior temperature to
maximum.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination. Due to the length of your vehicle/trailer
combination, you will have to travel an
additional distance beyond the vehicle you
are overtaking before returning to the
previous lane. Decoupling
atrailer G
WARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overru nbrake
is engaged. G
WARNING
Vehicles with level control:
The vehicle is lowered as soon as you
disconnect the trailer cable. This could result
in yourl imbs or those of other people that are
betwee nthe vehicle body and tires or
underneath the vehicle being trapped. There
is a risk of injury.
Make sure that nobody is in the immediate
vicinity of the wheel housings or under the
vehicle when you disconnectt he trailer cable.
! Do not disconnect a trailer with an
engaged overrun brake. Otherwise, your
vehicle could be damaged by the
rebounding of the overrun brake.
X Make sure that the automatic transmission
is set to position P.
X Apply the vehicle's electric parking brake.
X Start the engine.
X Close all doors and the tailgate.
X Apply the trailer's parking brake.
X Detach the trailer cable and decouple the
trailer.
X Switch off the engine. 262
Towing
atrailerDriving an d parking

Permissible trailer loads and drawbar
loads
Weight specifications Maximump
ermissible gross vehicle
weight rating
The gross trailer weight is calculated by
adding the weight of the trailer to the weight
of the load and equipment on the trailer.
Permissible gross weight :7,500 lb
(3,402 kg).
Permissible noseweight
The maximum permissible trailer drawbar
noseweight is the maximum weight with
which the trailer drawbar can be loaded:
600 lbs (272 kg).
Limit for Mercedes-Benz-approved trailer
couplings.
Loading atrailer R
When loading the trailer, make sure that
neithe rthe permissible gross weight of the
trailer nor the gross vehicle weight is
exceeded. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
You can find the maximum permissible
values on the type plates of your vehicle
and the trailer. When calculating how much
weight the vehicle and trailer may carry,
pay attention to the respective lowest
values.
R The trailer drawbarl oad on the ball coupling
must be added to the rear axle load to avoid
exceeding the permissible gross axle
weight. The permissible gross vehicle
weight is indicated on the identification
plate on the B-pillar on the driver's side of
the vehicle.
i Mercedes-Benz recommends atrailer
load where the trailer drawbar noseweight
accounts for 8% to 15% of the trailer's
permissible gross weight. i
The weight of additional accessories,
passengers, and cargo reduces the
permissible trailer load and drawbar load
for yourv ehicle.
Checking the vehicle and trailer weight R
To chec kthat the weights of the towing
vehicle and the trailer comply with the
maximum permissible values, have the
vehicle/trailer combination (including the
driver, passengers, and cargo with a fully
laden trailer) weighed on a calibrated
weighbridge.
R Check the gross axle weight rating of the
front and rear axles, the gross weight of the
trailer and trailer drawbarl oad. Removing the ball coupling
X Remove the spring cotter.
X Remove the bolt from the ball coupling
recess.
X Remove the ball coupling from the ball
coupling recess.
X Clean the ball coupling if it is dirty.
Information on cleaning and care of the trailer
tow hitch can be found at (Y page 376). Storing the ball coupling
G
WARNING
Do not carry the ball coupling in the vehicle
interior if it is not secured.
Otherwise, you and others could be injured by
the ball coupling being thrown around if you:
R brake sharply
R change direction suddenly
R are involved in an accident Towing
atrailer
263Driving an d parking Z

Trailer power supply
! You can connect accessorie swith a
maximum power consumption of 240 Wto
the permanent powe rsupply.
You must no tcharge a trailer battery using
the power supply.
The trailer socket of your vehicle is equipped
at the factory with apermanen tpower supply.
The permanent power supply is supplied via
trailer socket pin 4.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
Aq ualified specialist workshop can provide
more information about installing the trailer
electrics. 264
Towing
atrailerDriving an d parking

Useful information
............................266
Important safety notes ....................266
Displays and operation ....................267
Menus and submenus ......................270
Display messages ............................. 286
Warning and indicator lamps in the
instrument cluster ............................320 265On-board computer and displays

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Read the information on qualified
specialist workshops: (Y page 28).Important safety notes
G
WARNING
If you operate information systems and
communication equipment integrated in the
vehicle while driving, you will be distracted
from traffic conditions. You could also lose
control of the vehicle. There is a risk of an
accident.
Only operate the equipment when the traffic
situatio npermits .Ifyou are not sure that this
is possible, park the vehicle paying attention
to traffic conditions and operate the
equipment when the vehicle is stationary. G
WARNING
If the instrument cluster has failed or
malfunctioned, you may not recognize
function restrictions in systems relevant to
safety. The operating safety of your vehicle
may be impaired. There is a risk of an
accident.
Drive on carefully. Have the vehicle checked
at a qualified specialist workshop
immediately.
You must observe the legal requirements for
the country in which you are currently driving
when operating the on-board computer.
The on-board computer only shows messages
or warnings from certain systems in the multifunction display
.You should therefore
make sure your vehicle is operating safely at
all times. Otherwise, a vehicle that is not
operating safely may cause an accident.
For an overview, see the instrument panel
illustration (Y page 33).266
Important safety notesOn-board computer and displays

Displays and operation
Instrument cluster
Instrument cluster: miles
0002
Speedometer with segments (Y page 268)
0003 Fuel gauge
0021 Tachometer (Y page 268)
0020 Coolant temperature ( Ypage 267)
001E Multifunction display (Y page 269)
001F Instrumen tcluster lighting (Y page 267) Instrument cluster lighting
The lighting in the instrumen tcluster, in the
displays and the controls in the vehicle
interior can be adjusted using the brightness
control knob.
The brightness control knob is located on the
bottom left of the instrument cluster
(Y page 33).
X Turn the brightness control knob clockwise
or counter-clockwise.
If the light switch is set to 0006,0016or
000D, the brightness is dependent upon
the brightness of the ambien tlight.
i The light sensor in the instrumen tcluster
automatically controls the brightness of
the multifunction display. In daylight, the displays in the instrument
cluster are not illuminated. Coolant temperature display
G
WARNING
Driving when your engine is overheated can
cause some fluids which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening
the engine hood. Stay away fro mthe engine
if you see or hear steam coming from it.
Stop the vehicle in a safe location away from
other traffic. Turn off the engine, get out of the Displays and operation
267On-board computer and displays
Z

vehicle and do not stand near the vehicle until
the engine has cooled down.
! Adisplay message is shown if the coolant
temperature is too high.
If the coolant temperature is over
248 ‡(120 †), do not continue driving. The
engine will otherwise be damaged.
The coolan ttemperature gauge is in the
instrument cluster on the right-hand side
(Y page 33).
Under normal operating conditions and with
the specified coolant level, the coolant
temperature may rise to 248 ‡ (120 †). Tachometer
! Do not drive in the overrevving range, as
this could damage the engine.
The red band in the tachometer indicates the
engine's overrevving range.
The fuel supply is interrupted to protec tthe
engine when the red band is reached. Outside temperature display
You should pay special attention to road
conditions when temperatures are around
freezing point.
The outside temperature display is in the
multifunction display (Y page 269).
Changes in the outside temperature are
displayed after a short delay. Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
R Cruise control activated (Y page 195):
The segments light up from the stored
speed to the maximum speed.
R DISTRONIC PLUS activated (Y page 198):One or two segments in the set speed
range light up.
R DISTRONIC PLUS detectsav ehicle in front:
The segments between the speed of the
vehicle in fron tand the stored speed light
up. Operating the on-board computer
Overview 0002
Multifunctio ndisplay
0003 Switches on the Voice Control System;
see the separate operating instructions
0021 Right control panel
0020 Left control panel
001E Back button
X To activat ethe on-board computer: turn
the SmartKey to position 1in the ignition
lock.
You can control the multifunction display and
the settings in the on-board computer using
the buttons on the multifunction steering
wheel. 268
Displays and operationOn-board computer and displays