2015 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 0044in the direction of the
arrow until the holes in ball coupling 0087are
in line with the holes in ball coupling
recess 0085. Bolt
X Slide bolt 0083into the hole in the ball cou-
pling recess and the ball coupling to the
stop. Bolt and spring cotter
X Secure the bolt using spring cotter 0084. 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 moun-
ted, 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 cou-
pling 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 guaran-
teed.
Have the entire trailer tow hitch checked at aqualified specialist workshop. Coupling up a trailer
! Do not connect the trailer's brake system
(if featured) to the hydraulic brake system Towing a trailer
267Driving and parking Z

of the towing vehicle, as the latter is equip-
ped 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 cou-
pling up a trailer, please observe the fol-
lowing:
R Unless highway level has been set man-
ually, the vehicle is automatically low-
ered to highway level. This is the case if a
speed of 5 mph (8 km/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 cou-
pling, 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 vehi- cle, the safety switch applies the trailer's
brakes. Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed
restrictions. Make sure that your car/trailer
combination complies with the local regula-
tions: R in your place of residence
R in the location to which you are driving
The police and local authorities can provide
reliable information.
Observe the following when towing a trailer:
R To gain driving experience and to become
accustomed to the new handling charac-
teristics, you should practice the following
in a traffic-free location:
- cornering
- stopping
- backing up
R Before driving, check:
- trailer tow hitch
- safety switch for braked trailers
- safety chains
- electrical connections
- lights
- 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 268
Towing a trailerDriving and parking

using the brake controller and check
whether the brakes function correctly.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is
in motion.
R When you couple up a trailer, check at reg-
ular intervals that the load is firmly secured.If the trailer is equipped with trailer lights
and brakes, check the trailer to ensure that
these are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when driv- ing 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, do not brake suddenly, but
instead depress the brake pedal moder-
ately at first so that the trailer can activate its 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 dra-
matically while the air-conditioning system
is switched on, switch off the air-condition-
ing system.
Coolant heat can also be dissipated by
opening the windows and switching the ventilation blower and the interior temper-
ature to the highest level.
R When overtaking, pay particular attention
to the extended length of your vehicle/
trailer combination.
Due to the length of the vehicle/trailer
combination, you require additional road
space in relation to the vehicle you are
overtaking before you can change back to
the original 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 discon-
nect the trailer cable. This could result in your limbs or those of other people that are
between the vehicle body and tires or under-
neath 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 rebound- ing 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. Towing a trailer
269Driving and parking Z

X
Detach the trailer cable and decouple the
trailer.
X Switch off the engine. Permissible trailer loads and drawbar
loads
Weight specifications Maximum permissible gross vehicle
weight rating
The gross trailer weight is calculated by add-
ing 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 458).
Permissible noseweight
You will find installing dimensions and loads
under "Technical data" (Y page 458).
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 val-
ues 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 val-
ues.
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 per-
missible gross weight.
i The weight of additional accessories, pas-
sengers, and cargo reduces the permissi-
ble 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 max-
imum permissible values, have the vehicle/
trailer combination (including the driver,
passengers, and cargo with a fully laden
trailer) weighed on a calibrated weigh-
bridge.
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 cou-
pling 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 342)
and the safety notes regarding stowage
spaces (Y page 343).
Information on cleaning and care of the trailer tow hitch can be found at (Y page 382). 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: 270
Towing a trailerDriving an
d parking

R
brake sharply
R change direction suddenly
R are involved in an accident Trailer power supply
! You can connect accessories with a max-
imum power consumption of 240 W to 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. Towing a trailer
271Driving and parking Z

Driving systems
Display messages
Possible causes/consequences and
0050
0050Solutions 00AD
Attention Assist: Attention Assist:
Take a Break! Take a Break! Based on certain criteria, ATTENTION ASSIST has detected fatigue
or a lack of concentration on the part of the driver. A warning tone also sounds.
X If necessary, take a break.
During long journeys, take regular breaks in good time so you get enough rest. 00AD
Attention Assist Attention Assist
Inoperative Inoperative ATTENTION ASSIST is inoperative.
X Visit a qualified specialist workshop. 00C4
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 214)
R Vehicles with the AIRMATIC package (Y page 221)
X Observe the notes on towing a trailer (Y page 265).00C4
Compressor Compressor
Is
IsCool‐
Cool‐
ing
ing 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. 00C4
ABC Malfunction ABC 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. 312
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
0050
0050Solutions Blind Spot Assist
Blind Spot Assist
Currently Unavail‐ Currently Unavail‐
able See Opera‐ able See Opera‐
tor's Manual tor's Manual
or
Active Blind Spot
Active Blind Spot
Assist Currently Assist Currently
Unavailable See Unavailable See
Operator's Manual Operator's Manual Blind Spot Assist or Active Blind Spot Assist is temporarily inop-
erative. 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 sta-
tions or other sources of electromagnetic radiation.
The yellow 0063indicator lamps also light up in the exterior mir-
rors.
When the causes stated above no longer apply, the display mes-
sage 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 (Y page 190).
X Clean the sensors (Y page 381).
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 0076on the steering wheel to confirm the display mes-
sage. 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
0063indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Park Assist Can‐ Park Assist Can‐
celed celed 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 multi-
function steering wheel is not touched unintentionally. 316
Display
messagesOn-board computer and displays

R
Use the cargo tie-down rings and the parcel
nets to transport loads and luggage.
R Use cargo tie-down rings and fastening
materials appropriate for the weight and
size of the load.
R Hook in the cargo net when loading.
R Secure the load with sufficiently strong and
wear-resistant tie-downs. Pad sharp edges
for protection. 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 pro-
trude 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 342).
Glove box X
To open: pull handle 0043and open glove box
flap 0044.
X To close: fold glove box flap 0044upwards
until it engages.
i The glove box can be cooled and ventila-
ted (Y page 163). 0047
Glove box unlocked
0048 Glove box locked
The glove box can be locked and unlocked
using the mechanical key. Partition
0043for 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 0043forwards and
out
X To install: insert partition 0043and push it
back until it engages. Stowage areas
343Stowage and features Z