2017 MERCEDES-BENZ GLS Owners Manual

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

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

X
Secure the bolt using spring cotter

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

Important safety notes
G WARNIN G
If you operate information systems and com-
munication equipmen t integrate d in th e vehi-
cle while driving , you will be distracte d from
traffic conditions. You could also lose control
of th e vehicle. Ther e is a ris k of an accident.
Only operate th e equipmen t when th e traffic
situation permits. If you are no t sur e that this
is possible , park th e vehicl e payin g attention
to traffic condition s and operate th e equip-
men t when th e vehicl e is stationary.
You must observ e th e legal requirements for th e
country in whic h you are currentl y driving when
operating th e on-board computer.
G WARNIN G
If th e instrumen t cluste r has faile d or mal-
functioned, you may no t recognize function
restriction s in systems relevan t to safety. The
operating safet y of your vehicl e may be
impaired . Ther e is a ris k of an accident.
Drive on carefully. Hav e th e vehicl e checke d
at a qualified specialist workshop immedi-
ately.
If th e operating safet y of your vehicl e is
impaired , pull ove r as soo n as it is saf e to do so.
Contac t a qualified specialist workshop.
The on-board computer only shows message s or
warning s from certain systems in th e multifunc-
tion display. You should therefor e mak e sur e
your vehicl e is operating safely at all times .
Fo r an overview, see th e instrumen t panel illus-
tration ( Y
page 34).
Displays and operation
Instrument cluster lighting
The lighting in th e instrumen t cluster, in th e dis-
plays and th e control s in th e vehicl e interior can
be adjusted usin g th e brightness control knob.
The brightness control knob is locate d on th e
botto m lef t of th e instrumen t cluste r
( Y
page 34). X
Turn th e brightness control knob clockwise or
counter-clockwise.
If you tur n th e ligh t switch to X , ` or
X , th e brightness is dependen t upon th e
brightness of th e ambien t light.
i The ligh t sensor in th e instrumen t cluste r
automatically control s th e brightness of th e
multifunction display.
In daylight, th e displays in th e instrumen t
cluste r are no t illuminated.
Speedometer with segments The segments in th e speedometer indicat e
whic h spee d range is available. R
Cruis e control activated ( Y
page 172):
The segments ligh t up from th e store d spee d
to th e maximum speed. R
Distanc e Pilot DISTRONI C is activated
( Y
page 174):
On e or two segments in th e set spee d range
ligh t up. R
Distanc e Pilot DISTRONI C detects a vehicl e in
fron t moving mor e slowly than th e store d
speed:
The segments between th e spee d of th e vehi-
cle in fron t and th e store d spee d ligh t up.
Tachometer
! Do no t driv e in th e overrevving range, as this
could damag e th e engine.
The red ban d in th e tachometer indicates th e
engine's overrevving range.
The fuel suppl y is interrupted to protect th e
engin e when th e red ban d is reached.
Outside temperature display You should pay special attention to road condi-
tion s when temperatures are aroun d freezing
point.
Bea r in min d that th e outside temperature dis-
play indicates th e temperature measured and
does no t record th e road temperature.
The outside temperature display is in th e multi-
function display ( Y
page 231).Displays and operation 229
On-board computer and displays Z

There is a short delay before a change in outside
temperature appears in the multifunction dis-
play.
Coolant temperature gauge
G WARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
! A display message is shown if the coolant
temperature is too high.
If the coolant temperature is over 248 ‡
(120 †), do not continue driving. The engine
will otherwise be damaged.
The coolant temperature gage is in the instru-
ment cluster on the right-hand side ( Y
page 34).
Under normal operating conditions and with the
specified coolant level, the coolant temperature
may rise to 248 ‡ (120 †). Operating the on-board computer
Overview
C
Multifunction display D
Right control panel