towing MERCEDES-BENZ GLS 2018 Owner's Manual

m
Level controln
Compass with angle scale
Activating the driving dynamics display X
Switch on COMAND (see the Digital Opera-
tor's Manual). X
Press button C .
The driving dynamics display appears in the
COMAND display.
Towing a trailer
Important safety notes
G WARNING
Installing an unsuitable ball coupling may
result in overloading of the trailer tow hitch
and the rear axle. This applies especially if the
ball coupling in question is longer or angled
differently. This could seriously impair the
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 395).
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 distance224
Towing a trailer
Driving and parking

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.
More information on availability and installa-
tion can be obtained at any qualified special-
ist workshop. R
The bumpers of your vehicle are not suitable
for installing detachable trailer couplings. 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 372).
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 192)R
Blind Spot Assist ( Y
page 209)R
Active Lane Keeping Assist ( Y
page 215) 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 395).
Driving tips Also observe the notes on pulling away with a
trailer ( Y
page 143).
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 permissible 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 "Technical data" to
find out whether this applies to your vehicle
( Y
page 395). 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 maximum
permissible speed for car/trailer combinations
is greater than 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 lower gear in good time on long
and 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.Towing a trailer 225
Driving and parking Z

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 fas-
tened 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
Safety switch for braked trailers. Check the
specific legal requirements applicable to your
state.
If the trailer becomes detached from the tow-
ing vehicle, the safety feature triggers the
trailer brakes.
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
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 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-
ically while the air-condition ing 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.228
Towing a trailer
Driving and parking

Decoupling a trailer
G WARNING
If you uncoupl e a trailer wit h th e overrun
brake engaged, you could trap your han d
between th e vehicle and th e trailer drawbar .
There is a ris k of injury.
Do no t uncoupl e a trailer if th e overrun brake
is engaged.
G WARNING
Vehicles wit h level control:
The vehicle is lowered as soo n as you discon-
nect th e trailer cable. Thi s could result in your
limbs or those of other people that are
between th e vehicle bod y and tires or under-
neat h th e vehicle bein g trapped. There is a
ris k of injury.
Mak e sur e that nobod y is in th e immediate
vicinit y of th e whee l housings or under th e
vehicle when you disconnec t th e trailer cable.
! Do no t disconnec t a trailer wit h an engage d
overrun brake . Otherwise , your vehicle could
be damaged by th e reboundin g of th e overrun
brake .X
Shift th e transmissio n to position P .X
Apply th e vehicle' s electric parking brake .X
Start th e engine.X
Clos e th e doors and tailgate.X
Apply th e trailer's parking brake .X
Detach th e trailer cable and decoupl e th e
trailer .X
Switc h of f th e engine.
Permissible trailer loads an d drawbar
loads
Weight specifications
Maximum allowable gross mass
The gross vehicle weight of th e trailer is calcu-
lated by addin g th e weight of th e trailer to th e
weight of th e load and equipmen t on th e trailer .
You will fin d installin g dimensions and load s
under "Technical data" ( Y
page 395). Permissible noseweigh tYou will fin d installin g dimensions and load s
under "Technical data" ( Y
page 395).
Loading a trailer R
Whe n loadin g th e trailer , mak e sur e that nei-
ther th e permissible gross weight of th e trailer
no r th e gross vehicle weight are exceeded.
The permissible gross vehicle weight is indi-
cated on th e identification plat e located on
th e B-pilla r on th e driver's sid e of th e vehicle.
You can fin d th e maximum permissible values
on th e typ e plates of your vehicle and th e
trailer . Whe n calculatin g how muc h weight
th e vehicle and trailer may carry, pay atten-
tion to th e respective lowest values. R
The trailer drawbar load on th e ball couplin g
mus t be adde d to th e rea r axl e load to avoid
exceedin g th e permissible gross axl e weight .
The permissible gross vehicle weight is indi-
cated on th e identification plat e located on
th e B-pilla r on th e driver's sid e of th e vehicle.
i Mercedes-Ben z recommends a trailer load
wher e th e trailer drawbar noseweigh t
accounts fo r 8 % to 15 % of th e trailer's per -
missible gross weight .
i The weight of additional accessories , pas-
sengers, and cargo reduce s th e permissible
trailer load and drawbar load fo r your vehicle.
Checking th e vehicle an d trailer weigh tR
To chec k that th e weight s of th e towin g vehi-
cl e and th e trailer compl y wit h th e maximum
permissible values, hav e th e vehicle/trailer
combination (includin g th e driver , passen -
gers, and cargo wit h a full y lade n trailer )
weighed on a calibrated weighbridge .R
Chec k th e gross axl e weight ratin g of th e fron t
and rea r axles, th e gross weight of th e trailer
and th e trailer drawbar noseweight.
Removin g th e ball coupling X
Remov e th e sprin g cotter.X
Remov e th e bolt from th e ball couplin g
recess . X
Remov e th e ball couplin g from th e ball cou-
plin g recess .Towing a trailer 229
Driving and parking Z

Display messages
Possible causes/consequences and P Solutions
Blind Spo t Assist
Currently Unavaila‐
ble See Operator' s
Manual or Active
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
The radar sensor system is outside th e operating temperature
range. R
The radar sensor system is temporarily inoperative, e.g. due to
electromagneti 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 161).X
Restart th e engine.
Blind Spo t Assist
Not Available Whe n
Towing a Traile r
See Operator' s Man ‐
ual or Active Blind
Spo t Assist 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
Active 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 195).Display messages 26 9
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 300).
Glove box
X
To open: pull handle C and open glove box
flap D .X
To close: fold glove box flap D up until it
engages.
i The glove box can be cooled and ventilated
( Y
page 136).
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 C .X
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 301
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. R
If the relevant mobile phone network is not
available, no emergency call can be initiated.
The indicator lamp in the SOS button flashes
continuously.
No voice connection can be established to the
Mercedes-Benz Customer Assistance Center.
The Call Failed message appears on 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: press Roadside Assistance but-
ton 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 established, the Call
Connected message appears in the multifunc-
tion 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 319).
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 Mercedes-Benz
Service Center.
You may be charged for services such as repair
work and/or towing.316
Features
Stowage and features

To avoid damage to the vehicle, deactivate
Distance Pilot DISTRONIC 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
that the blower of the ventilation/heating
system is switched off (OFF button has
been pressed). R
the windshield wiper switch is at position
Z .
The vehicle may otherwise be damaged.
! In car washes with a towing mechanism,
make sure that the automatic transmission is
in transmission position \\ ; 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 ] auto-
matically and locks the wheels. You can
prevent this by shifting the automatic trans-
mission to \\ 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 ] auto-
matically and locks the wheels.
Observe the following to make sure that the
automatic transmission stays in position \\ :X
Make sure the vehicle is stationary and the
ignition is switched off. X
Turn the SmartKey to position in the ignition
lock H ( Y
page 140).
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
\\ . 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 t he 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. Care 331
Maintenance and care Z

Vehicle tool kit
General notes The vehicle tool kit can be found in the stowage
well under the cargo compartment floor.
Apart from certain country-specific variations,
the vehicles are not equipped with a tire-change
tool kit. Some tools for changing a wheel are
specific to the vehicle. For more information on
which tools are required to perform a wheel
change on your vehicle, consult a qualified spe-
cialist workshop.
Necessary tire-changing tools can include, for
example: R
jack R
wheel chock R
lug wrench R
ratchet wrench R
alignment bolt
Vehicles with a TIREFIT kit
C
Lug wrenchD
Towing eye

i Jumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop.
Towing and tow-starting
Important safety notes
G WARNING
Functions relevant to safety are restricted or
no longer available if: R
the engine is not running. R
the brake system or the power steering is
malfunctioning. R
there is a malfunction in the voltage supply
or the vehicle's electrical system.
If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that the steering moves freely.
G WARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible
gross weight of your vehicle, the: R
the towing eye could detach itself R
the vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per-
missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate ( Y
page 385).
! When Active Brake Assist, Distance Pilot
DISTRONIC or the HOLD function is activated,
the vehicle brakes automatically in certain
situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations: R
when towing the vehicle R
in the car wash ! Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop.
! Only secure the tow rope or tow bar at the
towing eyes, or the trailer tow hitch, if availa-
ble. You could otherwise damage the vehicle.
! Observe the following points when towing
with a tow rope: R
Secure the tow rope on the same side on
both vehicles. R
Make sure that the tow rope is not longer
than legally permitted. Mark the tow rope in
the middle, e.g. with a white c loth
(1
1.8 x 11.8 in). This will make other road
users aware that a vehicle is being towed. R
Only secure the tow cable to the towing
eyes or, if available, to the trailer tow hitch. R
Observe the brake lamps of the towing
vehicle while driving. Always maintain a dis-
tance a distance so that the tow rope does
not sag. R
Do not use steel cables or chains to tow
your vehicle. You could otherwise damage
the vehicle.
! Do not use the trailer tow hitch for recovery
or towing. Do not use the towing eye for
recovery. this could damage the vehicle. If in
doubt, have the vehicle recovered using a
crane.
! When towing, pull away slowly and
smoothly. Pull the towed vehicle as straight as
possible and not at an acute angle. Excessive
tractive power could damage the vehicles.
When towing, it is preferable to use a rigid tow-
ing bar as opposed to a tow rope. A rigid towing
bar helps to keep the tractive power low.
! When towing away vehicles with KEYLESS-
GO, use the key instead of the Start/Stop
button. The automatic transmission may oth-
erwise shift to position ] when you open the
driver's or front-passenger door, which could
damage the transmission.
! Do not tow with sling-type equipment. This
could damage the vehicle.Towing and tow-starting 349
Breakdown assistance Z