tow MERCEDES-BENZ GLS 2017 Service Manual

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 and secured
correctly the trailer may come loose. There is
a risk of an accident.
Install and secure the ball coupling as descri-
bed in the ball coupling installation instruc-
tions. Make sure that the ball coupling is
installed and secured correctly before every
journey.
X
Pull protective cap C in the direction of the
arrow, out of the ball coupling recess. X
Stow protective cap C so that it cannot be
thrown around.
Observe the loading guidelines ( Y
page 294)
and the safety notes regarding stowage
spaces ( Y
page 294). X
Insert the ball coupling horizontally into ball
coupling recess D in the direction of the
arrow until the holes in ball coupling

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
The yellow $ warning lamp and th e red I (US A only) or $
(Canada only) indicator lamp ligh t up.
The electric parking brak e is malfunctioning .
To release: X
Switc h off th e ignition and tur n it bac k on .X
Releas e th e electric parking brak e manually.
or X
Releas e th e electric parking brak e automatically ( Y
page 160).
If th e electric parking brak e still canno t be released:X
Do no t drive on .X
Consult a qualified specialist workshop .
The red I (US A only) or $ (Canada only) indicator lamp flashes
and th e yellow $ warning lamp lights up.
The electric parking brak e is malfunctioning .
To release: X
Switc h off th e ignition and tur n it bac k on .X
Releas e th e electric parking brak e manually.
To apply : X
Switc h off th e ignition and tur n it bac k on .X
Apply th e electric parking brak e manually.
If th e red I (US A only) or $ (Canada only) indicator lamp con-
tinue s to flash: X
Do no t drive on .X
Secur e th e vehicl e against rollin g away ( Y
page 367).X
Shift th e transmission to position P .X
Turn th e fron t wheels toward s th e curb.X
Consult a qualified specialist workshop .248
Display messages
On-board computer and displays

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

tem and for the PBAP and MAP Bluetooth ®
profiles. The prompt to confirm may take up
to two minutes to be displayed (see the man-
ufacturer's operating instructions).
Switching between mobile phones If you have authorized more than one mobile
phone, you can switch between the individual
phones.
Multimedia system: X
Select Connect Device .X
Select a mobile phone from the device list.
Media mode
General notes If you wish to play external media sources, the
default display must already be turned on. Fur-
ther information on media mode (see the Digital
Operator's Manual).
The following external media sources can be
used: R
Apple ®
devices (e.g. iPhone ®
)R
USB devices (e.g. USB stick, MP3 player)
( Y
page 292)R
CD R
DVD (COMAND) R
SD cards R
via devices connected by Bluetooth ®
i Information on single CD/DVD drive or DVD
changer (see the Digital Operator's Manual).
Using the device list Multimedia system: X
Select Media { Devices .
The available media sources will be shown.
The ; dot indicates the current setting.X
Select the media source.
Playable files are played. Inserting/removing an SD card Important safety notes
G WARNING
SD cards are small parts. They can be swal-
lowed and cause choking. This poses an
increased risk of injury or even fatal injury.
Keep the SD card out of the reach of children.
If a SD card is swallowed, seek medical atten-
tion immediately.
! If you are no longer using the SD card, you
should remove it and store it outside the vehi-
cle. High temperatures can damage the card.
Inserting an SD card The SD card slot is on the control panel. X
Insert the SD card into the SD card slot until
the SD card engages. The side with the con-
tacts must face downwards.
Removing an SD card X
Press the SD card.
The SD card is ejected. X
Remove the SD card.
Connecting USB devices
There are two USB ports in the stowage space
under the armrest. X
Connect the USB device to the USB port. X
Select the media source ( Y
page 292).292
Operating system
Multimedia system

Stowage areas
Loading guidelines
G WARNING
If objects, luggage or loads are not secured or
not secured sufficiently, they could slip, tip
over or be flung around and thereby hit vehicle
occupants. There is a risk of injury, particu-
larly in the event of sudden braking or a sud-
den change in direction.
Always store objects so that they cannot be
flung around. Secure objects, luggage or
loads against slipping or tipping before the
journey.
G WARNING
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. If the tailgate
is open when the engine is running, particu-
larly if the vehicle is moving, exhaust fumes
could enter the passenger compartment.
There is a risk of poisoning.
Turn off the engine before opening the tail-
gate. Never drive with the tailgate open.
G WARNING
The exhaust tail pipe and tail pipe trim can
become very hot. If you come into contact
with these parts of the vehicle, you could burn
yourself. There is a risk of injury.
Always be particularly careful around the
exhaust tail pipe and the tail pipe trim. Allow
these components to cool down before touch-
ing them.
The gross vehicle weight (GVW) is the vehicle
weight including fuel, vehicle tool kit, spare
wheel, installed accessories, vehicle occupants
and luggage/cargo.
Do not exceed the load limit or permitted gross
vehicle weight rating (GVWR) for your vehicle.
The gross load limit and the GVWR are specified
on the vehicle identification plate on the B-pillar
of the driver's door ( Y
page 356).
The load must also be distributed so that the
weight on each axle never exceeds the gross
axle weight rating (GAWR) for the front and rear
axles. The specifications for GVWR and GAWR are on the vehicle identification plate on the B-
pillar of the driver's door ( Y
page 356).
Observe the notes on loading the vehicle
( Y
page 356).
The handling characteristics of a laden vehicle
are dependent on the distribution of the load
within the vehicle. For this reason, you should
observe the following notes when transporting a
load: R
Never exceed the maximum permissible
gross vehicle mass or the gross axle weight
rating for the vehicle (including occupants). R
The cargo compartment is the preferred place
to carry objects. R
Position heavy loads as far forwards as pos-
sible and as low down in the cargo compart-
ment as possible. R
The load must not protrude above the upper
edge of the seat backrests. R
Always place the load against the rear or front
seat backrests. Make sure that the seat
backrests are securely locked into place. R
Always place the load behind unoccupied
seats if possible. R
Use the cargo tie-down rings and the parcel
nets to transport loads and luggage. R
Use cargo tie-down rings and fastening mate-
rials appropriate for the weight and size of the
load. R
Secure the load with sufficiently strong and
wear-resistant tie-downs. Pad sharp edges for
protection.
Stowage spaces
Important safety notes
G WARNING
If you transport objects in the vehicle interior
and these are not adequately secured, they
could slip or be flung around and thereby
strike vehicle occupants. In addition, cup
holders, open stowage spaces and mobile
phone brackets may not always be able to
hold the objects placed in them in the event of
an accident. There is a risk of injury, particu-
larly in the event of sharp braking or sudden
changes of direction.294
Stowage areas
Stowage and features

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

Vehicles with touchpad and COMAND X
To open: press button C at the front.
Armrest D folds out.
Depending on the vehicle equipment, a multi-
media connector unit with 2 USB ports (Media
Interface), e.g. for use with an iPod ®
, iPhone ®
or
MP3 player is installed in the stowage compart-
ment.
i There is a removable stowage tray in the
storage compartment, in which objects such
as an iPod ®
can be stored.
Eyeglasses compartment
X
To open: press marking C .
The eyeglasses compartment opens down. X
To close: press marking C again and the
eyeglasses compartment moves up and
engages.
Make sure that the eyeglasses compartment is
always closed while the vehicle is in motion.
Stowage compartment in the front cen-
ter console X
To open: slide cover C forwards.
Stowage compartment D appears.X
To close: pull cover C back as far as it will go.
Stowage compartment in the rear cen-
ter console X
To open: briefly press the stowage compart-
ment marking.
The stowage compartment opens.
i Depending on the vehicle's equipment,
there may be open stowage spaces above and
below the stowage compartment.
Stowage net
G WARNING
Vehicles with the Occupant Classification
System (OCS):
If the gross weight of the objects in the stow-
age net on the back of the front-passenger
seat is greater than 4.4 lb (2 kg), OCS cannot
correctly assess the occupant's weight cate-
gory. The front-passenger front air bag could
deploy without cause, or may fail to deploy in
the event of an accident. This poses an
increased risk of injury or even fatal injury.
Always observe the permissible gross weight
of 4.4 lb (2 kg). Stow and secure heavy
objects in the cargo compartment.296
Stowage areas
Stowage and features