2019 MERCEDES-BENZ GLS SUV ECU

The electric parking brake secures the vehicle
automatically if the HOLD function is activated
when the vehicle is stationary and:
R a system malfunction occurs
R the power supply is insufficient
On steep uphill or downhill gradients or if there
is a malfunction, the transmission may also be
automatically shifted to position 005D.AIRMATIC package
General notes AIRMATIC is an air suspension system with var-
iable damping for improved driving comfort.
Level control ensures the best possible suspen- sion and constant ground clearance, even with a laden vehicle. When you drive fast, the vehicle islowered automatically to improve driving safety
and to reduce fuel consumption. There is also
the option to manually adjust the vehicle level.
AIRMATIC consists of:
R level settings
R level control and
R ADS or ADS PLUS (Adaptive Damping Sys-
tem)
All vehicles (except Mercedes-AMG vehi-
cles): your vehicle may also be equipped with
the ACTIVE CURVE SYSTEM (Y page 186).
Mercedes-AMG vehicles: your vehicle is equip-
ped with the ACTIVE CURVE SYSTEM
(Y page 186).
Observe the notes on driving with a trailer
(Y page 222).
The vehicle level can be set using the DYNAMIC
SELECT controller (Y page 147) or the level but-
ton (Y page 187). The setting always corre-
sponds to the last selected function.
Important safety notes G
WARNING
When the vehicle is being lowered, people
could become trapped if their limbs are
between the vehicle body and the wheels or
underneath the vehicle. There is a risk of
injury. Make sure no one is underneath the vehicle or
in the immediate vicinity of the wheel arches
when the vehicle is being lowered.
If you unlock the vehicle or open a door, the
vehicle begins to compensate for load discrep-
ancies while still parked. However, for signifi-
cant level changes, such as after the vehicle has
been stationary for a long period, the engine
must be on. For safety reasons, the vehicle is
only lowered when the doors are closed. Low-
ering is interrupted if a door is opened, and it
continues once the door has been closed.
ADS and ADS PLUS (Adaptive Damping
System) General notes
The Adaptive Damping System automatically
controls the calibration of the dampers. The
damping characteristics adapt to the current
operating and driving situation.
The damping is tuned individually to each wheel
and depends on:
R your driving style, e.g. sporty
R the road surface conditions
R the drive program selected
R the vehicle level setting
Selecting Comfort mode In the
Comfort drive program, the driving char-
acteristics of your vehicle are more comforta-
ble. Therefore, select this mode if you favor a
more comfortable driving style. Also select the
Comfort drive program when driving fast on
straight roads, e.g. on straight stretches of high-
way. Driving systems
185Driving and parking Z

R
that are parallel to the direction of travel and
at least 39.5 in (1.0 m)longer than your vehi-
cle
R that are at right angles to the direction of
travel and at least 39.5 in (1.0 m) wider than
your vehicle
i Note that Active Parking Assist cannot
measure the size of a parking space if it is at
right angles to the direction of travel. You will
need to judge whether your vehicle will fit into the parking space.
When driving at speeds below 19 mph
(30 km/h), you will see parking symbol 0044as a
status indicator in the instrument cluster. When
a parking space has been detected, an arrow
towards the right or the left also appears. By
default, Active Parking Assist only displays park- ing spaces on the front-passenger side. Parking spaces on the driver's side are displayed as
soon as the turn signal on the driver's side is
activated. When parking on the driver's side,
this must remain activated until you confirm the
use of Active Parking Assist by pressing the
0076 button on the multifunction steering
wheel. The system automatically determines
whether the parking space is parallel or at right
angles to the direction of travel.
A parking space is displayed while you are driv- ing past it, and until you are approximately 50 ft
(15 m) away from it.
Parking G
WARNING
If you leave the driver's seat when the vehicle is being braked only by the Active Parking
Assist, it could roll away in the following sit-
uations:
R if there is a malfunction in the system or in
the voltage supply
R if the electrical system in the engine com-
partment, the battery or the fuses have
been tampered with
R if the battery is disconnected
R if the vehicle is accelerated, e.g. by a vehi-
cle occupant
There is a risk of an accident.
Before leaving the vehicle, always secure it
against rolling away. i
If Parking Assist PARKTRONIC detects
obstacles, Active Parking Assist will brake
automatically whilst the vehicle is parking.
You are responsible for braking in good time.
X Stop the vehicle when the parking space sym-
bol shows the desired parking space in the
instrument cluster.
X Shift the transmission to position 005E.
The Start
Start Parking Parking Assist?
Assist?Yes:
Yes:OK
OKNo:
No:
0038 message will appear on the multifunc-
tion display.
X To cancel the procedure: press the0038
button on the multifunction steering wheel or pull away.
or
X To park using Active Parking Assist: press
the 0076 button on the multifunction steering
wheel.
The Parking
Parking Assist AssistActive
ActiveAccelerate
Accelerate
and Brake Observe Surroundings
and Brake Observe Surroundings mes-
sage will appear on the multifunction display.
X Let go of the multifunction steering wheel.
X Back up the vehicle, being ready to brake at all
times. When backing up, drive at a speed
below approximately 6 mph (10 km/h). Oth-
erwise, Active Parking Assist will be canceled.
Active Parking Assist brakes the vehicle to a
standstill when the vehicle approaches the
rear border of the parking space.
Maneuvering may be required in tight parking
spaces.
The Parking Assist Active Select D Parking Assist Active Select D
Observe Surroundings
Observe Surroundings message will appear
on the multifunction display.
X Shift the transmission to position 005Bwhile
the vehicle is stationary.
Active Parking Assist immediately steers in
the other direction.
The Parking Parking Assist
AssistActive
ActiveAccelerate
Accelerate
and Brake Observe Surroundings
and Brake Observe Surroundings mes-
sage will appear on the multifunction display.
i You will achieve the best results by waiting
for the steering procedure to complete before
pulling away.
X Drive forwards and be ready to brake at all
times.
Active Parking Assist brakes the vehicle to a
standstill.
The Parking Assist Active Select R Parking Assist Active Select R
Observe Surroundings
Observe Surroundings message will appear
on the multifunction display. 194
Driving systemsDriving and parking

006D
Level control
006E Compass with angle scale
Activating the driving dynamics display X
Switch on COMAND (see the Digital Opera-
tor's Manual).
X Press button 0043.
The driving dynamics display appears in the
COMAND display. Towing a trailer
Important safety notes
G
WARNING
Installing an unsuitable ball coupling may
overload the trailer tow hitch and the rear
axle. This is particularly likely in the case of
longer or differently angled ball couplings.
Consequently, the driving characteristics may
be significantly impaired and the trailer may
detach. This presents the risk of an accident
or even fatal injuries!
Install only a ball coupling that adheres to the permissible dimensions and is designed for
your intended purpose for towing a trailer. Do
not make any changes to 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 392). 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 Towing a trailer
221Driving and parking Z

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.
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 0043in the direction of the
arrow, out of the ball coupling recess.
X Stow protective cap 0043so that it cannot be
thrown around.
Observe the loading guidelines (Y page 295)
and the safety notes regarding stowage
spaces (Y page 295). X
Insert the ball coupling horizontally into ball
coupling recess 0044in the direction of the
arrow until the holes in ball coupling 0087are in
line with the holes in ball coupling recess 0085. Towing a trailer
223Driving and parking Z

X
Slide bolt 0083into the hole in the ball coupling
recess and the ball coupling to the stop. X
Secure the bolt using spring cotter 0084.X
Check the ball coupling, bolt and spring cotter
for correct installation.
If the ball coupling cannot be correctly mounted,
remove the ball coupling. Under these circum-
stances, the ball coupling must not be used for
trailer towing.
Have the entire trailer tow hitch checked at a
qualified specialist workshop. Coupling up a trailer
! Do not connect the trailer's brake system (if
featured) to the hydraulic brake system of the towing vehicle, as the latter is equipped with
an anti-lock brake system. Doing so will result
in a loss of function of the brake systems of
both the vehicle and the trailer.
X Shift the transmission to position 005D.
X Apply the vehicle's electric parking brake.
X Start the engine.
X Vehicles with AIRMATIC Package: select
normal level and the Comfortdrive program.
X Switch off the engine.
X Close the doors and tailgate.
X Couple up the trailer.
X Establish the electrical connection between
the vehicle and the trailer.
X Check that the trailer lighting system is work-
ing.
X Push the combination switch upwards/down-
wards and check whether the corresponding
turn signal on the trailer flashes.
A trailer that is connected is recognized only
when the electrical connection is established
correctly and when the lighting system is work-
ing properly. The function of other systems also depends on this, for example:
R ESP ®
R Parking Assist PARKTRONIC
R Active Parking Assist
R Parking Package with rear view camera
R Active Blind Spot Assist
R Active Lane Keeping Assist
i Vehicles with the AIRMATIC Package: if you
couple up a trailer, the vehicle always remains
at normal level. When coupling up a trailer,
please observe the following:
R If the normal level has not been set man-
ually, the vehicle is automatically lowered
to normal level. This is the case if a speed of
5 mph (8 km/h) is reached.
R The Sport drive program is not available.
These restrictions apply to all accessories
powered through a connection to the trailer
power socket of your vehicle, e.g. a bicycle
carrier.
Observe the maximum permissible trailer
dimensions (width and length). 224
Towing a trailerDriving and parking

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-woundunder 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 sothat 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-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. Towing a trailer
225Driving and parking Z

Use only bicycle racks approved by
Mercedes-Benz.
Bicycle racks cause your vehicle's driving char-
acteristics to change. The vehicle: R is heavier
R is restricted in its acceleration and gradient-
climbing capability
R has an increased braking distance This could impair the handling characteristics.
Adapt your driving style accordingly. Maintain a
safe distance and drive carefully.
When using bicycle racks, set the tire pressure
on the rear axle of the vehicle for the maximum
load. Further information on tire pressure can be
found on the tire pressure table (Y page 355).Loading instructions
The greater the distance between the load's center of gravity and the ball head, the higher the load exerted on the trailer tow hitch.
Therefore, observe the following notes:
R Attach heavy bicycles as close as possible to the vehicle.
R Always distribute the load on the bicycle rack as symmetrically as possible to the vehicle longi-
tudinal axis.
Before loading the bicycle rack, Mercedes-Benz advises you to remove all add-on parts from the
bicycles, e.g. bicycle baskets, child seats or batteries. This will allow you to improve the aerody-
namic resistance and the bicycle rack's center of gravity.
Always secure bicycles against slipping and check that they are firmly seated at regular intervals.
Do not use tarpaulins or other covers. This could impair the driving characteristics and rear visibility. The aerodynamic resistance would also rise, and so would the load exerted on the trailer tow hitchas a result. Load distribution on the bicycle rack
0043 Distance in height between the center of gravity and the ball coupling
0044 Distance to the rear between the center of gravity and the ball coupling
0087 The center of gravity is located on the central axis of the vehicle 228
Bicycle rackDriving and parking

Display messages
Possible causes/consequences and
0050
0050Solutions The yellow
0024warning lamp and the red 0049(USA only) or 0024
(Canada only) indicator lamp light up.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
or X Release the electric parking brake automatically (Y page 159).
If the electric parking brake still cannot be released:
X Do not drive on.
X Consult a qualified specialist workshop. The red
0049(USA only) or 0024(Canada only) indicator lamp flashes
and the yellow 0024warning lamp lights up.
The electric parking brake is malfunctioning.
To release:
X Switch off the ignition and turn it back on.
X Release the electric parking brake manually.
To apply: X Switch off the ignition and turn it back on.
X Apply the electric parking brake manually.
If the red 0049(USA only) or 0024(Canada only) indicator lamp con-
tinues to flash:
X Do not drive on.
X Secure the vehicle against rolling away (Y page 374).
X Shift the transmission to position 005D.
X Turn the front wheels towards the curb.
X Consult a qualified specialist workshop. Display
messages
249On-board computer and displays Z