2014 MERCEDES-BENZ GL-Class towing

Ball coupling recess
Holes in the ball coupling and ball coupling recess
X Insert the ball coupling horizontally into ball
coupling recess ;in the direction of the
arrow until the holes in ball coupling =are
in line with the holes in ball coupling
recess ?. Bolt
X
Slide bolt Ainto the hole in the ball
coupling recess and the ball coupling to the
stop. Bolt and spring cotter
X
Secure the bolt using spring cotter B. 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 266
Towing a trailerDriving and 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 5 mph (8km/h) is reached.
R High-speed level is not available.
These restrictions apply to all accessories
powered through a connection to 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 Canadian provinces
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 A separate brake system for certain types
of trailer.
R A safety 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 a trailer
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 In order to accumulate driving experience
and accustom yourself to the new handling
characteristics, practice the following at a
location where there is no traffic:
-Cornering
- Stopping
- Backing up
R Before driving, check:
-the trailer tow hitch
- the safety switch for braked trailers
- the safety chains
- electrical connections
- the lights
- the wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check
whether the brakes function correctly. Towing a trailer
267Driving and parking Z

R
Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion.
R If you couple up a trailer, regularly check
that the cargo is securely fastened 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 repeatedly
shifts between gears on uphill or downhill
gradients, shift to a lower gear using the
left-hand steering wheel paddle shifter.
A lower 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 a trailer
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 overrun brake
is engaged. G
WARNING
Vehicles with level control:
The vehicle is lowered as soon as you
disconnect the trailer cable. This could result
in your limbs or those of other people that are
between the 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 disconnect the 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. 268
Towing a trailerDriving and parking

Permissible trailer loads and drawbar
loads
Weight specifications Maximum permissible 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.
You will find installing dimensions and loads
under "Technical data" (Y page 456).
Permissible noseweight
You will find installing dimensions and loads
under "Technical data" (Y page 456).
Loading a trailer R
When loading the trailer, make sure that
neither the 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 drawbar load 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 a trailer
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 your vehicle. Checking the vehicle and trailer weight R
To check that 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 drawbar load. 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.
X Stow the ball coupling so that it cannot be
thrown around.
Observe the loading guidelines
(Y page 340) and the safety notes regarding
stowage spaces (Y page 341).
Information on cleaning and care of the trailer
tow hitch can be found at (Y page 381). 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 a trailer
269Driving and parking Z

Trailer power supply
! You can connect accessories with a
maximum power consumption of 240 Wto
the permanent power supply.
You must not charge a trailer battery using
the power supply.
The trailer socket of your vehicle is equipped
at the factory with a permanent power 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.
A qualified specialist workshop can provide
more information about installing the trailer
electrics. 270
Towing a trailerDriving an
d parking

Display messages Possible causes/consequences and
M
MSolutions Á
Drive More Slowly Drive More Slowly You cannot change the vehicle level. Possible causes are:
R
you are driving too fast for the selected vehicle level.
R you are towing a trailer.
R the trailer-coupling socket is being used, e.g. for a bicycle rack.
X Drive more slowly and then select the desired vehicle level
again.
R
Vehicles with the ON&OFFROAD package (Y page 212)
R Vehicles with the AIRMATIC package (Y page 218)
X Observe the notes on towing a trailer (Y page 264).Á
Compressor Is Compressor Is
Cooling Cooling You have selected a higher vehicle level. The compressor first
needs to cool down because of frequent level changes.
X
Drive in a manner appropriate for the current vehicle level.
X Make sure that there is sufficient ground clearance.
X Allow the compressor to cool down.
When the compressor has cooled down, the display message
disappears. The vehicle then continues rising to the selected
level. Á
Malfunction Malfunction AIRMATIC is malfunctioning.
X
Drive as appropriate for the current vehicle level, but do not
exceed 50 mph (80 km/h).
X Make sure that there is sufficient ground clearance.
X Have the vehicle checked at a qualified specialist workshop. Á
Max. Speed 12 mph Max. Speed 12 mph You are exceeding the speed permissible for the selected off-road
level.
In addition, the vehicle level display appears between the vehicle
icon and the display message, and a warning tone sounds.
G WARNING
The vehicle could tip and rollover.
There is a risk of an accident.
X Adjust your driving style to the altered handling characteristics.
X Only make slight steering movements and avoid fast steering
movements.
X Do not exceed 12 mph (20 km/h) until the vehicle has reached
off-road level 2. 310
Display messagesOn-board computer and displays

Display messages Possible causes/consequences and
M
MSolutions Blind Spot Assist
Blind Spot Assist
Currently Currently
Unavailable See Unavailable See
Operator's Manual Operator's Manual
or
Active Blind Active Blind
Spot Assist
Spot Assist
Currently Currently
Unavailable See Unavailable See
Operator's Manual Operator's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily
inoperative. Possible causes are:
R
the sensors are dirty.
R function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio
stations or other sources of electromagnetic radiation.
The yellow 9indicator lamps also light up in the exterior
mirrors.
When the causes stated above no longer apply, the display
message disappears.
Blind Spot Assist or Active Blind Spot 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 rolling away ( Ypage 188).
X Clean the sensors (Y page 380).
X Restart the engine. Blind Spot Assist or Active Blind Spot Assist is deactivated while
towing a trailer.
You have established the electrical connection between the trailer
and your vehicle.
X
Press aon the steering wheel to confirm the display
message. Blind Spot Assist Blind Spot Assist
Inoperative Inoperative
or
Active Blind Spot
Active Blind Spot
Assist Inoperative Assist Inoperative Blind Spot Assist or Active Blind Spot Assist is defective.
The yellow
9indicator lamps also light up in the exterior
mirrors.
X Visit a qualified specialist workshop. Park Assist Park Assist
Canceled Canceled The driver's door is open and the driver's seat belt has not been
fastened.
X
Repeat the parking process with the seat belt fastened and the
driver's door closed. You have inadvertently touched the multifunction steering wheel
while steering intervention was active.
X
While steering intervention is active, make sure that the
multifunction steering wheel is not touched unintentionally. 314
Display
messagesOn-board computer and displays

Stowage space
Important safety notes G
WARNING
If objects in the passenger compartment are
stowed incorrectly, they can slide or be
thrown around and hit vehicle occupants.
There is a risk of injury, particularly in the
event of sudden braking or a sudden change
in direction.
R Always stow objects so that they cannot be
thrown around in such situations.
R Always make sure that objects do not
protrude from stowage spaces, parcel nets
or stowage nets.
R Close the lockable stowage spaces while
driving.
R Stow and secure objects that are heavy,
hard, pointy, sharp-edged, fragile or too
large in the cargo compartment.
Observe the loading guidelines (Y page 340).
Glove box X
To open: pull handle :and open glove box
flap ;.
X To close: fold glove box flap ;upwards
until it engages.
i The glove box can be cooled and
ventilated (Y page 163). 1
Glove box unlocked
2 Glove box locked
The glove box can be locked and unlocked
using the mechanical key. Partition
:for stowing flat objects is located
in the upper section of the glove box. It can
be removed to increase the stowage space in
the glove box.
X To remove: pull partition :forwards and
out
X To install: insert partition :and push it
back until it engages. Stowage areas
341Stowage and features Z