2016 MERCEDES-BENZ GLS SUV towing

E
Level control
F Compass with angle scale
Activating the driving dynamics display X
Switch on COMAND Online. You can find fur-
ther information in the separate COMAND
Online operating instructions.
X Press button :.
The driving dynamics display appears in the
COMAND display. Towing a trailer
Important safety notes
G
WARNING
Vehicles with level control:
The vehicle level may be changed uninten-
tionally, e.g. by other persons. If this happens while you are coupling or decoupling a trailer,
you could become trapped. In addition, other
people could become trapped if their limbs
are between the vehicle body and the wheels or underneath the vehicle. There is a risk of
injury.
When coupling or decoupling a trailer, make
sure that no one:
R opens or closes the doors or the tailgate
R initiates a level change or turns the
DYNAMIC SELECT Controller
R locks or unlocks the vehicle G
WARNING
You could lose control of the vehicle/trailer
combination if it begins to swerve. The vehi- cle/trailer combination could even overturn.
There is a risk 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 the maximum permissible load for a carrier system is exceeded, the carrier could come
loose from the vehicle and endanger other
road users. There is a risk of an accident and injury.
Never exceed the maximum permissible load
when using a carrier.
Exceeding the maximum permissible nose-
weight of the trailer drawbar on the ball coupling
may cause damage to the following:
R your vehicle
R the trailer
R the ball coupling
R trailer tow hitch
The vehicle/trailer combination could become
unstable.
If the noseweight used is lower than the mini-
mum permissible noseweight, the vehicle/
trailer combination could also become unstable. To avoid hazardous situations:
R make sure to check the noseweight before
each journey
R use a drawbar noseweight as close as possi-
ble to the maximum noseweight
R do not exceed the maximum permissible
noseweight
R do not use a noseweight lower than the min-
imum noseweight
When reversing the 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.
Make sure that the following values are not
exceeded:
R the permissible trailer drawbar noseweight
R the permissible trailer load Towing a trailer
233Driving and parking Z

R
the permissible rear axle load of the towing
vehicle
R the maximum permissible gross vehicle
weight of both the towing vehicle and the
trailer
The applicable permissible values, which must
not be exceeded, can be found:
R in your vehicle documents
R on the identification plates of the trailer tow
hitch and the trailer
R on the vehicle identification plate
If the values differ, the lowest value applies.
You will find the values approved by the manu-
facturer on the vehicle identification plates and
those for the towing vehicle under "Technical
data" (Y page 390).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison to
when driving without a trailer.
The vehicle/trailer combination:
R is heavier
R is restricted in its acceleration and gradient-
climbing capability
R has an increased braking distance
R is affected more by strong crosswinds
R demands more sensitive steering
R has a larger turning circle
This can impair the vehicle's handling charac-
teristics. Adapt your driving style accordingly.
Maintain a safe distance. Drive carefully.
When towing a trailer, always adjust your speed to the current road and weather conditions. Do
not exceed the maximum permissible speed for
your vehicle/trailer combination. Notes on towing a trailer
General notes !
If you have a trailer tow hitch retrofitted,
changes to the engine cooling system may be necessary, depending on the vehicle type.
If you have a trailer tow hitch retrofitted,
observe the anchorage points on the chassis.
Check the tyre pressures when towing a trailer.
You will find the values in the tyre pressure table in the vehicle fuel filler flap (Y page 364).Please note that when towing a trailer, the fol-
lowing driving systems have limited availability
or are not available at all.
R Parking Assist PARKTRONIC (Y page 201)
R Blind Spot Assist (Y page 219)
R Active Lane Keeping Assist (Y page 224)
R Parking Pilot (Y page 204)
On vehicles without level control, the height of
the ball coupling will alter according to the load
placed on the vehicle. If necessary, use a trailer
with a height-adjustable drawbar.
You will find permissible trailer loads under
"Technical data" (Y page 390).
Driving tips Observe the information on ESP
®
trailer stabili-
sation (Y page 74) and on pulling away with a
trailer (Y page 151).
Select the Comfortdrive program using the
DYNAMIC SELECT controller (Y page 155).
The maximum permissible speed for vehicle/
trailer combinations depends on the type of
trailer. Before beginning the journey, check the
trailer's documents to see what the maximum
permissible speed is for your trailer. Observe the legally prescribed maximum speed in the rele-
vant country.
For certain Mercedes-Benz vehicles, the maxi-
mum permissible rear axle load is increased
when towing a trailer. See the "Technical Data"
section to find out whether this applies to your
vehicle (Y page 390). If you utilise any of the
added maximum rear axle load when towing a
trailer, the vehicle/trailer combination may not
exceed a maximum speed of 100 km/h for rea-
sons concerning the operating permit. This also
applies in countries in which the permissible
maximum speed for vehicle/trailer combina-
tions is above 100 km/h.
When towing a trailer, your vehicle's handling
characteristics will be different to when driving
without a trailer and the vehicle will consume
more fuel.
Use the left-hand gearshift paddle to shift to a
lower gear on long and steep downhill gradients.
This also applies if you have activated cruise
control, the speed limiter or Distance Pilot
DISTRONIC.
This will use the braking effect of the engine, so
less braking will be required to maintain the
vehicle speed. This relieves the load on the 234
Towing a trailerDriving an
d parking

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 under any circumstances.
X Do not countersteer.
X Brake, if necessary.
R Maintain a greater distance to the vehicle in
front than when driving without a trailer.
R Avoid braking abruptly. If possible, brake gen-
tly at first to allow the trailer to run on. Then,
increase the braking force rapidly.
R The values given for gradient-climbing capa-
bilities from a standstill refer to sea level.
When driving in mountainous areas, note that
the power output of the engine, and conse-
quently the vehicle's gradient-climbing capa-
bility from a standstill, decrease with increas- ing altitude. Swivelling the ball coupling out/in
Using the switch in the driver's door G
WARNING
If the ball coupling is not engaged, the trailer
may come loose. There is a risk of an accident. Make sure that the ball coupling is securely
engaged and locked in position.
! Do not attempt to speed the up the swing-
out procedure by applying additional pressure
with your foot. The system could otherwise be
mechanically damaged.
In order to tow a trailer with your vehicle, you
must swing out the ball coupling using the
switch in the driver's door or in the tailgate.
The trailer socket is integrated into the ball cou- pling and swivels out with it.
Release the ball coupling only when the swivel
range is unobstructed. Swivelling out:
X Make sure that the vehicle is stationary.
X Shift the transmission to position P.
X Switch the ignition on.
X Pull switch :briefly.
After a short time, the ball coupling swivels
out from under the rear bumper. It can take up to seven seconds before the ball coupling
visibly swivels out.
X Remove the protective cap from the ball cou-
pling and store it in a safe place.
Until the ball coupling vertically engages in a
securely locked position:
R indicator lamp ;flashes
R the multifunction display shows the display
message Trailer coupling extend‐ Trailer coupling extend‐
ing...
ing... .
The ball coupling swivels back into the out-of-
use position when:
R you drive off before the Trailer
Trailercoupling
coupling
extending...
extending... display message has disap-
peared from the multifunction display
R the ball coupling encounters an obstacle in
the swivel range
Folding in:
X Make sure that the vehicle is stationary and
the trailer cables are disconnected.
X Place the protective cap on the ball coupling.
X Shift the transmission to position P.
X Switch the ignition on.
X Pull switch :briefly.
After a short time, the ball coupling swivels in under the rear bumper. It can take up to seven
seconds before the ball coupling visibly swiv- els in. Towing a trailer
235Driving and parking Z

Until the ball coupling engages in a securely
locked position under the bumper:
R indicator lamp ;flashes
R the multifunction display shows the display
message Trailer coupling extend‐
Trailer coupling extend‐
ing...
ing...
The ball coupling swivels back into the out-of-
use position when:
R you drive off before the Trailer
Trailer coupling
coupling
extending...
extending... display message has disap-
peared from the multifunction display
R the ball coupling encounters an obstacle in
the swivel range
Using the switch in the tailgate Swivelling out:
X Make sure that the vehicle is stationary.
X Open the tailgate.
X Pull switch :briefly.
After a short time, the ball coupling swivels
out from under the rear bumper. It can take up to seven seconds before the ball coupling
visibly swivels out.
X Remove the protective cap from the ball cou-
pling and store it in a safe place.
Until the ball coupling vertically engages in a
securely locked position:
R indicator lamp ;flashes
R the multifunction display shows the display
message Trailer coupling extend‐
Trailer coupling extend‐
ing... ing... The ball coupling swivels back into the out-of-
use position when:
R you drive off before the Trailer
Trailercoupling
coupling
extending...
extending... display message has disap-
peared from the multifunction display
R the ball coupling encounters an obstacle in
the swivel range
Folding in:
X Make sure that the vehicle is stationary and
the trailer cables are disconnected.
X Place the protective cap on the ball coupling.
X Open the tailgate.
X Pull switch :briefly.
After a short time, the ball coupling swivels in under the rear bumper. It can take up to sevenseconds before the ball coupling visibly swiv-
els in.
Until the ball coupling engages in a securely
locked position under the bumper:
R indicator lamp ;flashes
R the multifunction display shows the display
message Trailer coupling extend‐ Trailer coupling extend‐
ing...
ing...
The ball coupling swivels back into the out-of-
use position when:
R you drive off before the Trailer
Trailercoupling
coupling
extending...
extending... display message has disap-
peared from the multifunction display
R the ball coupling encounters an obstacle in
the swivel range Coupling up a trailer
Important safety notes G
WARNING
Vehicles with level control:
If you disconnect the trailer cable, the vehicle is lowered. This can cause you or others to
become trapped between the vehicle body
and tyres, or underneath the vehicle. This
poses a risk of injury.
Make sure that no-one is in the immediate
vicinity of the wheel arch or underneath the
vehicle when disconnecting the trailer cable. 236
Towing a trailerDriving and parking

Vehicles with the AIRMATIC package
!
Before beginning the journey, make sure
that the trailer support wheel is completely
raised. Otherwise, the trailer or the vehicle
could be damaged by the lowered trailer sup- port wheel during the journey.
X Shift the transmission to position P.
X Apply the electric parking brake.
X Start the engine.
X Vehicles with the Off-Road Engineering
package:
set the vehicle level to normal level
(Y page 192).
X Vehicles without the Off-Road Engineer-
ing package: select theComfortdrive pro-
gram using the DYNAMIC SELECT controller
(Y page 197).
X Switch off the engine.
X Close the doors and tailgate.
X Position the trailer horizontally behind the
vehicle.
X Couple up the trailer.
X Establish the electrical connection between
the vehicle and the trailer.
X Check that the trailer lighting system is work-
ing.
X Push the combination switch upwards and
downwards and check whether the corre-
sponding turn signal indicator on the trailer is
flashing.
A connected trailer is only detected when the
electrical connection is established correctly
and when the lighting system is working prop-
erly. The function of other systems also depends on this, for example:
R ESP ®
R Parking Assist PARKTRONIC
R Parking Pilot
R Active Blind Spot Assist
R Active Lane Keeping Assist
i Vehicles with the AIRMATIC package:
if
you couple up a trailer, the vehicle initially
remains at the selected level of the drive pro- gram set. Observe the following when cou-
pling up a trailer:
R If the normal level was not selected previ-
ously, the vehicle automatically adopts the normal level starting from a speed of 30 km/h. Even at higher speeds, it does not
drop below the normal level.
R Vehicle levels below the normal level are
not available.
R The raised level is available up to a speed of
30 km/h.
R This also applies when using accessories
that are plugged into the socket of the
trailer tow hitch (e.g. a bicycle rack).
R Before driving with a trailer, please observe
the information on the trailer support
wheel. Uncoupling a trailer
Important safety notes G
WARNING
If you uncouple a trailer with an engaged over- run brake, you could trap your hand between
the vehicle and the trailer drawbar. This poses a risk of injury.
Do not uncouple a trailer with an engaged
overrun brake. G
WARNING
Vehicles with level control:
If you disconnect the trailer cable, the vehicle is lowered. This can cause you or others to
become trapped between the vehicle body
and tyres, or underneath the vehicle. This
poses a risk of injury.
Make sure that no-one is in the immediate
vicinity of the wheel arch or underneath the
vehicle when disconnecting 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.
! Remove the adapter cable before folding in
the ball coupling. You could otherwise dam-
age the rear bumper and the adapter cable.
Vehicles with the AIRMATIC package X
Shift the transmission to position P.
X Apply the electric parking brake. Towing a trailer
237Driving and parking Z

X
Start the engine.
X Close the doors and tailgate.
X Secure the trailer against rolling away.
X Remove the trailer cable and decouple the
trailer.
X Switch off the engine. Trailer power supply
! You can connect accessories with a power
rating of up to 180 W to the permanent power
supply and with a power rating of up to 180 W to the power supply that is switched on via the ignition lock.
The trailer battery may not be charged from
the power supply.
When it leaves the factory, your vehicle's trailer
socket is equipped with a permanent power
supply and a power supply that is switched on
via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin 10.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
You can find more information about fitting the
trailer electrics at a qualified specialist work-
shop.
X To switch the connected power supply on
or off: turn the key to position 2or0respec-
tively (Y page 148). Failure check for LEDs
If LED lamps are fitted in the trailer, a malfunc-
tion message may appear in the multifunction
display even if there is no fault. The reason for
the error message may be that the current has
fallen below the minimum of 50 mA. To ensure reliable indication of the failure, each
LED chain in the trailer lighting must be guaran-
teed a minimum current of 50 mA. Trailer with 7-pin connector
General notes Trailer with 7-pin connector:
you can connect
to the 13-pin socket on the ball coupling using
an adapter or, if necessary, an adapter cable.
Both can be obtained at a qualified specialist
workshop.
Fitting the adapter !
Make sure that there is sufficient cable play
so that the cable cannot become detached
when cornering.
! Remove the adapter cable before folding in
the ball coupling. You could otherwise dam-
age the rear bumper and the adapter cable. X
Open the socket cover.
X Insert the plug connector with lug :into
groove =on the socket.
X Turn bayonet connection ;clockwise 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. 238
Towing a trailerDriving and parking

Problems with trailer towing
Problem
Possible causes/consequences and
M
MSolutions The displaced ball cou-
pling does not reach the
securely locked position. R
The indicator lamp in the button flashes.
R The Check trailer hitch lock Check trailer hitch lock message appears in the multi-
function display.
X Initiate a new swivelling procedure.
If the ball coupling does not reach the safely engaged position as a
result:
X Start the engine
or
X Pull and hold the button during the whole swivelling procedure.
If the unlocked ball coupling does not reach the safely engaged posi- tion even after several attempts:
X Make sure that there is sufficient ground clearance before continu-
ing the journey.
X Consult a qualified specialist workshop.
As long as the Check trailer hitch lock
Check trailer hitch lock display message is
shown in the multifunction display, no trailer should be attached. Unlocking using the
button in the tailgate:
The ball coupling does
not swivel, even though:
R
the vehicle is station-
ary
R no trailer cable is con-
nected
R the button was briefly
pulled The on-board voltage is too low.
X Start the engine.
If the ball coupling still does not unlock:
X Consult a qualified specialist workshop. Towing a trailer
239Driving and parking Z

Problem
Possible causes/consequences and
M
MSolutions Unlocking using the
button in the driver's
door:
The ball coupling does
not swivel, even though:
R the vehicle is station-
ary
R no trailer cable is con-
nected The on-board voltage is too low.
X Engage park position P.
X Switch on the power supply.
or X Start the engine.
If the ball coupling still does not unlock: X Consult a qualified specialist workshop. The ball coupling does
not swivel. The indicator
lamp in the button is
flashing permanently.
The
Check trailer Check trailer
hitch lock
hitch lock message
appears in the multifunc- tion display. There is a malfunction in the release electronics.
X When the ball coupling is retracted: pull and hold the button in
the tailgate until the ball coupling engages into a securely engaged
and locked in a vertical position and then engages again under the
bumper.
X When the ball coupling is extended: pull and hold the button in
the tailgate until the ball coupling engages underneath the bumper.
If the ball coupling still does not unlock:
X Consult a qualified specialist workshop. 240
Towing a trailerDriving and parking