towing MERCEDES-BENZ GLS 2017 Owner's Manual

driving characteristics and the trailer can
come loose. There is a risk of an accident.
You should only ever install a ball coupling
that has the permissible dimensions and that
is designed to meet your trailer-towing
requirements. Do not modify the ball coupling
or the trailer tow hitch.
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 387).
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
When the vehicle/trailer combination begins
to lurch, you could lose control of it. The vehi-
cle/trailer combination could even rollover.
There is a risk of an accident.
On no account should you attempt to
straighten up the vehicle/trailer combination
by increasing the speed. Reduce vehicle
speed and do not countersteer. Apply the
brake as necessary.
Please observe the manufacturer's operating
instructions for the trailer coupling if a detach-
able trailer coupling is used.
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 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 the vehicle documents R
on the identification plates for the trailer tow
hitch and the trailer R
on the vehicle identification plate
If the values differ, the lowest value applies.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with 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 could impair the handling characteristics.
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 cooling system and drive train
may be necessary, depending on the vehicle
type.
If you have a trailer tow hitch retrofitted,
observe the anchorage points on the chassis
frame. R
Do not exceed the legally prescribed maxi-
mum speed for vehicle/trailer combinations
in the relevant country.
This lowers the risk of an accident. R
Only install an approved trailer coupling on
your vehicle.
Further information on availability and on
installation is available from any authorized
Mercedes-Benz Center. R
The bumpers of your vehicle are not suitable
for installing detachable trailer couplings.222
Towing a trailer
Driving and parking

R
Do not install hired trailer couplings or other
detachable trailer couplings on the bumpers
of your vehicle. R
If you no longer need the ball coupling,
remove it from the ball coupling recess. This
will reduce the risk of damage to the ball cou-
pling.
When towing a trailer, set the tire pressure on
the rear axle of the towing vehicle for the max-
imum load. You will find the values in the tire
pressure table in the fuel filler flap of the vehicle
( 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 190)R
Blind Spot Assist ( Y
page 207)R
Active Lane Keeping Assist ( Y
page 213)
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 installing dimensions and loads
under "Technical data" ( Y
page 387).
Driving tips Observe the information on ESP ®
trailer stabili-
zation ( Y
page 68) and on pulling away with a
trailer ( Y
page 141).
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. Observe the legally pre-
scribed maximum speed in the relevant country.
For certain Mercedes-Benz vehicles, the maxi-
mum permissible rear axle load is increased
when towing a trailer. See "Technical data" to
find out whether this applies to your vehicle
( Y
page 387). If you utilize any of the added
maximum rear axle load when towing a trailer,
the vehicle/trailer combination may not exceed
a maximum speed of 60 mph (100 km/h) for
reasons concerning the operating permit. This
also applies in countries in which the permissi-
ble maximum speed for vehicle/trailer combi-
nations is above 60 mph (100 km/h).
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a trailer. Use the left-hand steering wheel paddle shifter
to shift into a lowe r g ear in good time on long
a
nd steep downhill gradients.
This also applies if you have activated cruise
control or Distance Pilot DISTRONIC.
This will use the braking effect of the engine, so
that less braking will be required to maintain the
speed. This relieves the load on the brake sys-
tem 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 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, decreases with increasing altitude.
Installing the ball coupling
G WARNING
If the ball coupling is not correctly installed
and secured, it can come loose during the
journey and endanger other road users. There
is a risk of an 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.Towing a trailer 223
Driving an d parking Z

Towing a trailer There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed restric-
tions. Make sure that your car/trailer combina-
tion complies with the local regulations: R
in your place of residence R
in the location to which you are driving
The police and local authorities can provide reli-
able information.
Observe the following when towing a trailer: R
To gain driving experience and to become
accustomed to the new handling characteris-
tics, 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
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 regular
intervals that the load is firmly secured. If the
tra i ler 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 driving
without one. Avoid sudden steering move-
ments. 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 moderately 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 gra-
dients, 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 instal-
led, the trailer brakes. R
If the coolant temperature increases dramat-
i cally while the air-conditioning system is
switched on, switch off the air-conditioning
system.
Coolant heat can also be dissipated by open-
ing the windows and switching the ventilation
blower and the interior temperature 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 com-
bination, 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-226
Towing a trailer
Driving an d parking

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 rebounding of the overrun
brake. X
Shift the transmission to position P .X
Apply the vehicle's electric parking brake. X
Start the engine. X
Close the doors and tailgate. X
Apply the trailer's parking brake. X
Detach the trailer cable and decouple the
trailer. X
Switch off the engine.
Permissible trailer loads and drawbar
loads
Weight specifications
Maximum allowable gross mass The gross vehicle weight of the trailer is calcu-
lated 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 387).
Permissible noseweight
You will find installing dimensions and loads
under "Technical data" ( Y
page 387).
Loading a trailer R
When loading the trailer, make sure that nei-
ther the permissible gross weight of the trailer
nor the gross vehicle weight are exceeded.
The permissible gross vehicle weight is indi-
cated on the identification plate located 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 atten-
tion 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 indi-
cated on the identification plate located 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 permissible
trailer load and drawbar load for your vehicle.
Checking the vehicle and trailer weight R
To check that the weights of the towing vehi-
cle and the trailer comply with the maximum
permissible values, have the vehicle/trailer
combination (including the driver, passen-
gers, 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 the trailer drawbar noseweight.
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 294)
and the safety notes regarding stowage spaces
( Y
page 294).
Information on cleaning and care of the trailer
tow hitch ( Y
page 329).
Trailer power supply
! Accessories with a maximum power con-
sumption of 180 W can be connected to the
permanent power supply.Towing a trailer 227
Driving an d parking Z

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.228
Towing a trailer
Driving and parking

Display messages
Possible causes/consequences and P Solutions
Blind Spo t Assist
Currently Unavaila‐
ble See Operator' s
Manual or A ctive
Blind Spo t Assist
Currently Unavaila‐
ble See Operator' s
Manual Blind Spot Assis t or Active Blind Spot Assis t is temporarily inoperative.
Possibl e causes are: R
th e radar sensor system is outside th e operating temperature rangeR
th e radar sensor system is temporarily inoperative, e.g. due to elec -
tromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiation
The yellow c indicator lamp s also ligh t up in th e exterio r mirrors.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Blind Spot Assis t or Active Blind Spot Assis t is operational again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 159).X
Restart th e engine.
Blind Spo t Assist
Not Available Whe n
Towing a Traile r
See Operator' s Man ‐
ual or A ct. Blind
Spo t Asst. Not
Available Whe n Tow ‐
ing a Traile r See
Operator' s Manual Blind Spot Assis t or Active Blind Spot Assis t is deactivated while tow-
ing a trailer .
You hav e established th e electrical connection between th e trailer and
your vehicle. X
Press v on th e steering whee l to confirm th e display message .
Blind Spo t Assist
inoperative or A ctive
Blind Spo t Assist
inoperative Blind Spot Assis t or Active Blind Spot Assis t is malfunctioning .
The yellow c indicator lamp s also ligh t up in th e exterio r mirrors.X
Visit a qualified specialist workshop .
Parkin g Pilot Can ‐
celed The driver's door is open .X
Repeat th e parking gap measuremen t and parking process wit h th e
driver's door closed .
You hav e inadvertentl y touched th e multifunction steering whee l while
steering intervention was active .X
Whil e steering intervention is active , mak e sur e that th e multifunc-
tion steering whee l is no t touched unintentionally.
The vehicl e has started to skid and ES P ®
has intervened.X
Use Parking Pilo t again later ( Y
page 193).
Parkin g Pilot Inop‐
erativ e PARKTRONI C Parking Assis t is malfunctioning or faulty.X
Follow th e instruction s and helpful hints in th e "Problem s wit h
PARKTRONI C Parking Assist" section ( Y
page 193).
If th e multifunction display still shows th e display message :X
Visit a qualified specialist workshop .Display messages 26 5
On-board computer and displays Z

R
Always stow objects in such a way that they
cannot be tossed about in these or similar
situations. R
Always make sure that objects do not pro-
trude out of the stowage spaces, luggage
nets or stowage nets. R
Ensure that closable stowage spaces are
shut before beginning your journey. R
Always stow and secure heavy, hard, poin-
ted, sharp-edged, fragile or large objects in
the cargo compartment.
Observe the loading guidelines ( Y
page 294).
Glove box
X
To open: pull handle C and open glove box
flap D .X
To close: fold glove box flap D upwards until
it engages.
i The glove box can be cooled and ventilated
( Y
page 135).
G
Glove box unlocked
H
Glove box locked
The glove box can be locked and unlocked using
the mechanical key. Partition C 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 out partition CX
To install: insert partition C and push it back
until it engages.
Stowage compartment under the arm-
rest
Vehicles without touchpad X
To open: pull handle C up.
The armrest folds out.Stowage areas 295
Sto wag e an d features Z

lished between the Customer Assistance Center
and the vehicle occupants. R
If the vehicle occupants respond, the
Mercedes-Benz Customer Assistance Center
attempts to get more information on the
emergency. R
If there is no response from the vehicle occu-
pants, an ambulance is immediately sent to
the vehicle.
If no voice connection can be established to the
Mercedes-Benz Customer Assistance Center,
the system has been unable to initiate an emer-
gency call.
This can occur, for example, if the relevant
mobile phone network is not available. The indi-
cator lamp in the SOS button flashes continu-
ously.
The Call Failed message appears in the mul-
tifunction display and must be confirmed.
In this case, summon assistance by other
means.
Making an emergency call
X
To initiate an emergency call manually:
press cover C briefly to open.X
Press and hold the SOS button for at least one
second D .
The indicator lamp in SOS button D flashes
until the emergency call is concluded. X
Wait for a voice connection to the Mercedes-
Benz Customer Assistance Center. X
After the emergency call, close cover C .
If the mobile phone network is unavailable,
mbrace will not be able to make the emergency
call. If you leave the vehicle immediately after
pressing SOS button D , you do not know if
mbrace has successfully made the emergency
call. In this case, always summon assistance by
other means. Breakdown assistance button X
To call Roadside Assistance: press Road-
side Assistance button C .
This initiates a call to the Mercedes-Benz Cus-
tomer Assistance Center.
The indicator lamp in Roadside Assistance
button C flashes while the call is active. The
Connecting Call message appears in the
multifunction display. The audio output is
muted.
If a connection can be made, the Call Con‐
nected message appears in the multifunction
display.
If a mobile phone network and GPS reception
are available, the system transfers data to the
Mercedes-Benz Customer Assistance Center,
for example: R
current location of the vehicle R
vehicle identification number
The multimedia system display indicates that a
call is active. During the call, you can change to
the navigation menu by pressing the NAVI but-
ton on the multimedia system, for example.
Voice output is not available in this case.
A voice connection is established between the
Mercedes-Benz Customer Assistance Center
and the vehicle occupants.
From the remote malfunction diagnosis, the
Mercedes-Benz Customer Assistance Center
can ascertain the nature of the problem
( Y
page 313).
The Mercedes-Benz Customer Assistance Cen-
ter either sends a qualified Mercedes-Benz tech-
nician or makes arrangements for your vehicle
to be transported to the nearest authorized
Mercedes-Benz Center.
You may be charged for services such as repair
work and/or towing.310
Features
Stowage and features

obtained at a qualified specialist workshop, e.g.
an authorized Mercedes-Benz Center.
Driving abroad An extensive Mercedes-Benz Service network is
also available in other countries. You can obtain
further information from any authorized
Mercedes-Benz Center.
Care
General notes
H Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man-
ner.
! For cleaning your vehicle, do not use any of
the following: R
dry, rough or hard cloths R
abrasive cleaning agents R
solvents R
cleaning agents containing solvents
Do not scrub.
Do not touch the surfaces or protective films
with hard objects, e.g. a ring or ice scraper.
You could otherwise scratch or damage the
surfaces and protective film.
! Do not park your vehicle for a long period of
time directly after cleaning, particularly after
cleaning the wheel rim with wheel cleaner.
Wheel cleaner can lead to the increased cor-
rosion of the brake discs and pads. Therefore,
drive for a few minutes after cleaning. By
heating up the brakes, the brake discs and
pads dry. The vehicle can then be parked for a
long period of time.
Regular care of your vehicle is a condition for
retaining the quality in the long term.
Use care products and cleaning agents recom-
mended and approved by Mercedes-Benz. Washing the vehicle and cleaning the
paintwork
Automatic car wash
G WARNING
Braking efficiency is reduced after washing
the vehicle. There is a risk of an accident.
After the vehicle has been washed, brake
carefully while paying attention to the traffic
conditions until full braking power is restored.
! Before driving into an automatic car wash,
make sure that it is suitable for the dimen-
sions of the vehicle. In particular, make sure
that: R
there is enough ground clearance between
the vehicle underbody and the guide rails of
the automatic car wash. R
the clearance width of the automatic car
wash is sufficient, particularly the width of
the guide rails. R
you enter the automatic car wash straight
and in the center of the guide rails in order
to avoid damaging the tires or wheel rims.
Fold in the exterior mirrors before the vehicle
is washed. The exterior mirrors could other-
wise be damaged.
! When DISTRONIC PLUS or the HOLD func-
tion is activated, the vehicle brakes automat-
ically in certain situations.
To avoid damage to the vehicle, deactivate
DISTRONIC PLUS and the HOLD function in
the following or similar situations: R
when towing the vehicle R
in the car wash
! Never clean your vehicle in a Touchless
Automatic Car Wash as these use special
cleaning agents. These cleaning agents can
damage the paintwork or plastic parts.
! Make sure that: R
the side windows and the sliding sunroof
are fully closed. R
the ventilation/heating is switched off (the
OFF button has been pressed). R
the windshield wiper switch is in position 0 .
Otherwise, the vehicle might be damaged.324
Care
Maintenance and care

! In car washes with a towing mechanism,
make sure that the automatic transmission is
in transmission position N , otherwise the
vehicle could be damaged. R
Vehicles with a SmartKey:
Do not remove the SmartKey from the igni-
tion lock. Do not open the driver's door or
front-passenger door when the engine is
switched off. Otherwise, the automatic
transmission selects park position P auto-
matically and locks the wheels. You can
prevent this by shifting the automatic trans-
mission to N beforehand.R
Vehicles with KEYLESS-GO:
Do not open the driver's door or front-
passenger door when the engine is
switched off. Otherwise, the automatic
transmission selects park position P auto-
matically and locks the wheels.
Observe the following to make sure that the
automatic transmission stays in position N :X
Make sure the vehicle is stationary and the
ignition is switched off. X
Turn the SmartKey to position 2 in the ignition
lock ( Y
page 138).
Use the SmartKey instead of the Start/Stop
button on vehicles with KEYLESS-GO. X
Depress and hold the brake pedal. X
Shift the automatic transmission to position
N . X
Release the brake pedal. X
Release the electric parking brake. X
Switch off the ignition and leave the SmartKey
in the ignition lock.
You can wash the vehicle in an automatic car
wash from the very start.
If the vehicle is very dirty, pre-wash it before
cleaning it in an automatic car wash.
After using an automatic car wash, wipe off wax
from the windshield and the wiper blades. This
will prevent smears and reduce wiping noises
caused by residue on the windshield.
Washing by hand
In some countries, washing by hand is only
allowed at specially equipped washing bays.
Observe the legal requirements in all countries
concerned. X
Do not use hot water and do not wash the
vehicle in direct sunlight. X
Use a soft sponge to clean. X
Use a mild cleaning agent, such as a car
shampoo approved by Mercedes-Benz. X
Thoroughly hose down the vehicle with a gen-
tle jet of water. X
Do not point the water jet directly towards the
air inlets. X
Use plenty of water and rinse out the sponge
frequently. X
Rinse the vehicle with clean water and dry
thoroughly with a chamois. X
Do not let the cleaning agent dry on the paint-
work.
When using the vehicle in winter, remove all
traces of road salt deposits carefully and as
soon as possible.
Power washers
G WARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause invisible exterior damage
to the tires or chassis components. Compo-
nents damaged in this way may fail unexpect-
edly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced imme-
diately.
! Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about the
correct distance is available from the equip-
ment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
Do not aim directly at any of the following: R
Tires R
Door gaps, roof gaps, joints, etc. R
Electrical components R
Battery R
Connectors R
Lamps R
Seals R
Trim R
Ventilation slots Care 325
Maintenance and care Z