2018 MERCEDES-BENZ GLS SUV towing

with the curb or other road boundaries. Be par-
ticularly aware of other road users, e.g. cyclists,
that are directly next to your vehicle.
Obstacles such as traffic pylons on the lane or
projecting out into the lane are not detected.
An inappropriate steering intervention, e.g. afterintentionally driving over a lane marking, can be
corrected at any time if you steer slightly in theopposite direction.
Distance Pilot DISTRONIC with Steering Pilot
cannot continuously keep your vehicle in lane. In
some cases, the steering intervention is not suf-
ficient to bring the vehicle back to the lane. In
such cases, you must steer the vehicle yourself
to ensure that it does not leave the lane.
The support provided by the system can be
impaired if:
Rthere is poor visibility, e.g. due to insufficient
illumination of the road, or due to snow, rain,
fog or heavy spray
Rthere is glare, e.g. from oncoming traffic, the
sun or reflections (e.g. when the road surface
is wet)
Rthe windshield is dirty, fogged up, damaged or
covered, for instance by a sticker, in the vicin-
ity of the camera
Rthere are no or several unclear lane markings
for one lane, e.g. roadworks
Rthe lane markings are worn away, dark or cov-
ered up, e.g. by dirt or snow
Rthe distance to the vehicle in front is too short
and thus the lane markings cannot be detec-
ted
Rthe lane markings change quickly, e.g. lanes
branch off, cr oss one another or merge
Rthe road is narrow and winding
Rthere are strong shadows cast on the road
The system is switched to passive and no longer
assists you by performing steering interventions if:
Ryou actively change lane
Ryou switch on the turn signal
Rtake your hands off the steering wheel or do
not steer for a prolonged period of time
iAfter you have finished changing lanes,
Steering Pilot is automatically active once
more. Steering Pilot cannot provide assistance:
Ron very sharp corners
Rwhen towing a trailer
Rwhen a loss of tire pressure or a defective tire
has been detected and displayed
Observe the important safety notes on Distance Pilot DISTRONIC (
Ypage 176).
The steering interventions are carried out with a
limited steering moment. The system requires
the driver to keep his hands on the steering
wheel and to steer himself.
If you do not steer yourself or if you take your
hands off the steering wheel for a prolonged
period of time, the system will first alert you with
a visual warning. A steering wheel symbol
appears in the multifunction display. If you have
still not started to steer and have not taken hold
of the steering wheel after five seconds at the
latest, a warning tone also sounds to remind you
to take control of the vehicle. Steering Pilot is
then switched to passive. Distance Pilot
DISTRONIC remains active.
Activating Steering Pilot
XActivate Distance Pilot DISTRONIC with
Steering Pilot using the on-board computer
(
Ypage 241).
The Steering Pilot Onmessage appears
on the multifunction display. Steering Pilot is
activated.
Information in the multifunction display
If Steering Pilot is activated but not ready for a
steering intervention, steering wheel symbol :
appears in gray. If the system provides you with support by means of steering interventions,
symbol :is shown in green.
Deactivating Steering Pilot
XDeactivate Distance Pilot DISTRONIC with
Steering Pilot using the on-board computer
(
Ypage 241).
The Steering Pilot Offmessage appears
on the multifunction display. Steering pilot is
deactivated.
Driving systems183
Driving and parking
Z

HOLD function
General notes
The HOLD function can assist the driver in the
following situations:
Rwhen pulling away, especially on steep slopes
Rwhen maneuvering on steep slopes
Rwhen waiting in traffic
The vehicle is kept stationary without the driver having to depress the brake pedal.
The braking effect is canceled and the HOLD
function deactivated when you depress the
accelerator pedal to pull away.
iDo not use the HOLD function when driving
off-road, on steep uphill or downhill gradients
or on slippery or loose surfaces. The HOLD
function cannot hold the vehicle on such sur-
faces.
Important safety notes
GWARNING
If the vehicle is only braked using the HOLD
function, the vehicle may roll away in the fol-
lowing situations when you leave the vehicle:
Rif there is a malfunction in the system or in the voltage supply
Rif the HOLD function is deactivated by
depressing the accelerator pedal or brake
pedal, e.g. by a vehicle occupant
Rif the electrical system in the engine com-
partment, the battery or the fuses are tam-
pered with or the battery is disconnected
There is a risk of an accident.
Always deactivate the HOLD function and
secure the vehicle against rolling away before
you leave it.
!When Distance Pilot DISTRONIC or the
HOLD function is activated, the vehicle
brakes automatically in certain situations.
To avoid damage to the vehicle, deactivate
Distance Pilot DISTRONIC and the HOLD
function in the following or similar situations:
Rwhen towing the vehicle
Rin the car wash
Deactivate the HOLD function (
Ypage 187).
Activation conditions
You can activate the HOLD function if:
Rthe vehicle is stationary
Rthe engine is running or if it has been auto-
matically switched off by the ECO start/stop
function
Rthe driver's door is closed or your seat belt is
fastened
Rthe electric parking brake is released
Rthe transmission is in position h,kori
RDistance Pilot DISTRONIC is deactivated
Activating the HOLD function
XMake sure that the activation conditions are
met.
XDepress the brake pedal.
XQuickly depress the brake pedal further
until :appears in the multifunction display.
The HOLD function is activated. You can
release the brake pedal.
iIf depressing the brake pedal the first time
does not activate the HOLD function, wait
briefly and then try again.
Deactivating the HOLD function
The HOLD function is deactivated automatically
if:
Ryou depress the accelerator and the trans-
mission is in position hork
Ryou shift the transmission to position j
Ryou depress the brake pedal again with a cer-
tain amount of pressure until:disappears
from the multifunction display
Ryou secure the vehicle using the electric park- ing brake
Ryou activate Distance Pilot DISTRONIC
iAfter a time, the electric parking brake
secures the vehicle and relieves the service
brake.
Driving systems187
Driving and parking
Z

:Warning lamp
If Blind Spot Assist is activated, warning lamp :
in the exterior mirrors lights up yellow at speeds
of up to 20 mph (30 km/ h). At speeds above
20 mph (30 km/h), the warning lamp goes out
and Blind Spot Assist is operational.
If a vehicle is detected within the blind spot
monitoring range at speeds above 20 mph
(30 km/h), warning lamp :on the correspond-
ing side lights up red. This warning is always
emitted when a vehicle enters the blind spot
monitoring range from behind or from the side.
When you overtake a vehicle, the warning only
occurs if the difference in speed is less than
7 mph (12 km/h).
If you select the reverse gear, Blind Spot Assist
is not operational.
The brightness of the warning lamps is auto-
matically adapted to the brightness of the sur-
roundings.
Collision warning
If a vehicle is detected in the monitoring range of
Blind Spot Assist and you switch on the corre-
sponding turn signal, a double warning tone
sounds. Red warning lamp :flashes. If the turn
signal remains on, detected vehicles are indica-
ted by the flashing of red warning lamp :.
There are no further warning tones.
Switching on Blind Spot Assist
XMake sure that Blind Spot Assist is activated
in the on-board computer (Ypage 242).
XTurn the SmartKey to position 2in the igni-
tion lock.
Warning lamps :in the e
xterior mirrors light
up red for approximately 1.5 seconds and
then turn yellow.
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connection.
This can be accomplished by checking the trailer
lighting. In this event, Blind Spot Assist is deac-
tivated. The warning lamp lights up yellow in the
exterior mirrors and the Blind Spot Assist
Not Available When Towing a TrailerSee Operator's Manualmessage appears in
the multifunction display.
iYou can deactivate the warning lamps in the
exterior mirrors.
To do so, switch off Blind Spot Assist when:
Rthe SmartKey is in position 2in the igni-
tion lock
Rthe engine is not running
Lane Keeping Assist
General notes
:Lane Keeping Assist camera
Lane Keeping Assist monitors the area in front of
your vehicle with camera :, which is mounted
at the top of the windshield. Lane Keeping Assist
detects lane markings on the road and can warn
you before you leave your lane unintentionally.
This function is available in the range between
40 mph and 120 mph (60 km/h and 200 km/h).
A warning may be given if a front wheel passes
over a lane marking. It will warn you by means of
intermittent vibration in the steering wheel for
up to 1.5 seconds.
Important safety notes
GWARNING
Lane Keeping Assist cannot always clearly
detect lane markings.
Driving systems211
Driving and parking
Z

Course-correcting brake application
If Active Blind Spot Assist detects a risk of a lat-
eral collision in the monitoring range, a course-
correcting brake application is carried out. This
is meant to assist you in avoiding a collision.
GWARNING
A course-correcting brake application cannot always prevent a collision. There is a risk of an
accident.
Always steer, brake or accelerate yourself,
especially if Active Blind Spot Assist warns
you or makes a course-correcting brake appli-
cation. Always maintain a safe distance at the
sides.
If a course-correcting brake application occurs,
red warning lamp :flashes in the exterior mir-
ror and a double warning tone sounds. In addi-
tion, a display underlining the danger of a side
collision appears in the multifunction display.
In very rare cases, the system may make an
inappropriate brake application. A course-cor-
recting brake application may be interrupted at
any time by countersteering slightly or acceler-
ating.
The course-correcting brake application is avail-
able in the speed range between 20 mph
(30 km/h) and 120 mph (200km/ h).
Either no braking application, or a course-cor-
recting brake application adapted to the driving situation occurs if:
Rthere are vehicles or obstacles, e.g. crash
barriers, located on both sides of your vehicle.
Ra vehicle approaches you too closely at the
side.
Ryou have adopted a sporty driving style with
high cornering speeds.
Ryou clearly brake or accelerate.
Ra driving safety system intervenes, e.g. ESP®
or PRE-SAFE®Brake.
RESP®is switched off.
Rthe offroad program is activated (vehicles
without the Offroad Engineering package).
Rthe Offroad or Offroad Plus drive program is
activated (vehicles with the Off-Road Engi-
neering package).
Rthe LOW RANGE offroad gear is activated
(vehicles with the Offroad Engineering pack-
age).
Ra loss of tire pressure or a defective tire is
detected.
Switching on Active Blind Spot Assist
XMake sure that Active Blind Spot Assist
(Ypage 242) is activated in the on-board
computer.
XTurn the SmartKey to position 2in the igni-
tion lock.
Warning lamps :in the exterior mirrors light
up red for approximately 1.5 seconds and
then turn yellow.
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connection.
This can be accomplished by checking the trailer
lighting. Active Blind Spot Assist is then deacti-
vated. The indicator lamp lights up yellow in the
exterior mirrors and the Active Blind Spot
Asst. Not Available When Towing aTrailer See Operator's Manualmessage
appears in the multifunction display.
Active Lane Keeping Assist
General notes
Active Lane Keeping Assist monitors the area in
front of your vehicle by means of multifunction
camera :at the top of the windshield. Various
different areas to the front, rear and side of your
vehicle are also monitored with the aid of the
radar sensor system. Active Lane Keeping
Assist detects lane markings on the road and
can warn you before you leave your lane unin-
tentionally. If you do not react to the warning, a
Driving system s215
Driving an d parking
Z

WhenAdaptiveis selected, no warning vibra-
tion occurs if:
Ryou switch on the turn signals. In this event,
the warnings are suppressed for a certain
period of time
Ra driving safety system intervenes, e.g.
ABS, BAS or ESP®
Ryou accelerate hard, e.g. kickdown
Ryou brake hard
Ryou steer actively, e.g. swerve to avoid an
obstacle or change lanes quickly
Ryou cut the corner on a sharp bend
Towing a trailer
When you attach a trailer, make sure you have
correctly established the electrical connection.
This can be accomplished by checking the trailer
lighting. Lane-correcting brake application does
not take place when towing a trailer. Active Lane
Keeping Assist is not activated and the lines in
the assistance graphic are gray.
Off-road driving systems
4MATIC (permanent four-wheel drive)
4MATIC ensures that all four wheels are perma-
nently driven. Together with ESP®and 4ETS, it
improves the traction of your vehicle whenever
a drive wheel spins due to insufficient grip.
If you fail to adapt your driving style, 4MATIC can
neither reduce the risk of accident nor override the laws of physics. 4MATIC cannot take
account of road, weather and traffic conditions.
4MATIC is only an aid. You are responsible for
the distance to the vehicle in front, for vehicle
speed, for braking in good time and for staying in
your lane.
!Never tow the vehicle with one axle raised.
This may damage the transfer case. Damage
of this sort is not covered by the Mercedes-
Benz Limited Warranty. All wheels must
remain either on the ground or be fully raised.
Observe the instructions for towing the vehi-
cle with all wheels in full contact with the
ground.
!A function or performance test should only
be carried out on a two-axle dynamometer.
Before you operate the vehicle on such a
dynamometer, please consult a qualified workshop. You could otherwise damage the
drive train or the brake system.
iIn wintry driving conditions, the maximum
effect of 4MATIC can only be achieved if you
use winter tires (M+S tires), with snow chains
if necessary.
Further information about "Driving off-road"
(
Ypage 170).
DSR (Downhill Speed Regulation)
General notes
DSR is an aid to assist you when driving down-
hill. It keeps the speed of travel at the speed
selected on the on-board computer. The steeper
the downhill gradient, the greater the DSR brak-
ing effect on the vehicle. When driving on flat
stretches of road or on an uphill gradient, the
DSR braking effect is minimal or nonexistent.
DSR controls the vehicle’s speed when it is acti- vated and the transmission is in position D,Ror
N . You can drive at a higher or a lower speed
than that set on the on-board computer at any
time by accelerating or braking.
Important safety notes
GWARNING
If the speed driven and the set speed deviate and you activate DSR on a slippery road sur-
face, the wheels may lose traction. There is an
increased danger of skidding and accidents.
Before switching DSR on, please take into
consideration the road surface and the differ- ence between driving speed and the set
speed.
If you fail to adapt your driving style, DSR can
neither reduce the risk of accident nor override the laws of physics. DSR cannot take account of
road, weather and traffic conditions. DSR is only
an aid. You are responsible for the distance to
the vehicle in front, for vehicle speed, for brak-
ing in good time and for staying in your lane.
You are always responsible for keeping control
of the vehicle and for assessing whether the
downhill gradient can be managed. DSR may not always be able to keep to the set speed, depend-
ing on road surface and tire conditions. Select a
set speed suitable for the prevailing conditions
and when necessary, apply the brakes manually.
218Driving systems
Driving and parking

ELevel control
FCompass with angle scale
Activating the driving dynamics display
XSwitch on COMAND (see the Digital Opera-
tor's Manual).
XPress button:.
The driving dynamics display appears in the
COMAND display.
Towing a trailer
Important safety notes
GWARNING
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" (
Ypage 395).
GWARNING
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 asdescribed. Before every journey, ensure that
the ball coupling is secured with the bolt and
the corresponding spring cotter.
GWARNING
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:
Rthe permissible trailer drawbar noseweight
Rthe permissible trailer load
Rthe permissible rear axle load of the towing
vehicle
Rthe 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:
Rin the vehicle documents
Ron the identification plates for the trailer tow
hitch and the trailer
Ron 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:
Ris heavier
Ris restricted in its acceleration and gradient-
climbing capability
Rhas an increased braking distance
224Towing a trailer
Driving and parking

Ris affected more by strong crosswinds
Rdemands more sensitive steering
Rhas 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.
RDo not exceed the legally prescribed maxi-
mum speed for vehicle/trailer combinations
in the relevant country.
This lowers the risk of an accident.
ROnly install an approved trailer coupling on
your vehicle.
More information on availability and installa-
tion can be obtained at any qualified special-
ist workshop.
RThe bumpers of your vehicle are not suitable
for installing detachable trailer couplings.
RDo not install hired trailer couplings or other
detachable trailer couplings on the bumpers
of your vehicle.
RIf 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 (
Ypage 372).
Please note that when towing a trailer, the fol-
lowing driving systems have limited availability
or are not available at all:
RParking Assist PARKTRONIC (Ypage 192)
RBlind Spot Assist (Ypage 209)
RActive Lane Keeping Assist (Ypage 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" (
Ypage 395).
Driving tips
Also observe the notes on pulling away with a
trailer (Ypage 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
(
Ypage 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:
XDo not accelerate.
XDo not counter-steer.
XBrake if necessary.
Towing a trailer225
Driving and parking
Z

RMaintain a greater distance from the vehicle
in front than when driving without a trailer.
RAvoid braking abruptly. If possible, brake gen-tly at first to allow the trailer to run on. Then,
increase the braking force rapidly.
RThe 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
GWARNING
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.
GWARNING
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.
GWARNING
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.
XPull protective cap :in the direction of the
arrow, out of the ball coupling recess.
XStow protective cap :so that it cannot be
thrown around.
Observe the loading guidelines (
Ypage 300)
and the safety notes regarding stowage
spaces (
Ypage 300).
XInsert the ball coupling horizontally into ball
coupling recess ;in the direction of the
arrow until the holes in ball coupling =are in
line with the holes in ball coupling recess ?.
226Towing a trailer
Driving and parking