ECU MERCEDES-BENZ GLS 2018 Owner's Guide

When the HOLD function is activated, the trans-
mission is automatically shifted to position ]
if: R
the driver's door is open and the driver's seat
belt is unfastened R
the engine is switched off, unless it is auto-
matically switched off by the ECO start/stop
function
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 ] .
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 is
lowered 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 189).
Mercedes-AMG vehicles: your vehicle is equip-
ped with the ACTIVE CURVE SYSTEM
( Y
page 189).
Observe the notes on driving with a trailer
( Y
page 225).
The vehicle level can be set using the DYNAMIC
SELECT controller ( Y
page 147) or the level but-
ton ( Y
page 190). 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 mode188
Driving systems
Driving and parking

i Note that Parking Pilot PARKTRONIC cannot
measure the depth of parking spaces if they
are 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 D as a
status indicator in the instrument cluster. When
a parking space has been detected, an arrow
towards the right or the left also appears. Park-
ing Pilot only displays parking spaces on the
front-passenger side as standard. 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 Parking Pilot by pressing the v button
on the multifunction steering wheel. The system
automatically determines whether the parking
space is parallel or at right angles to the direc-
tion 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 vehicle when it is only being
braked by Active Parking Assist it could roll
away if: R
there is a malfunction in the system or in
the voltage supply. R
the electrical system in the engine com-
partment, the battery or the fuses have
been tampered with. R
the battery is disconnected. R
the accelerator pedal has been depressed,
e.g. by a vehicle 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, Parking Pilot brakes automatically
whilst the vehicle is being parked. 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 R .
The Start Parking Pilot? Yes: OK No:
8 message appears in the multifunction
display. X
To cancel the procedure: press the 8
button on the multifunction steering wheel or
pull away.
or X
To park using Parking Pilot: press the v
button on the multifunction steering wheel.
The Parking Pilot Active Accelerate
and Brake Observe Surroundings mes-
sage appears in 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, Parking Pilot is canceled immediately.
Parking Pilot 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 Pilot Active Select D
Observe Surroundings message appears in
the multifunction display. X
Shift the transmission to position D while the
vehicle is stationary.
Parking Pilot immediately steers in the other
direction.
The Parking Pilot Active Accelerate
and Brake Observe Surroundings mes-
sage appears in 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.
Parking Pilot brakes the vehicle to a standstill.
The Parking Pilot Active Select R
Observe Surroundings message appears in
the multifunction display.
As soon as the parking procedure is complete,
the Parking Pilot Finished message
appears and a warning tone sounds. The vehicle
is now parked. The vehicle is kept stationary
without the driver having to depress the brakeDriving systems 197
Driving and parking Z

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
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 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 300)
and the safety notes regarding stowage
spaces ( Y
page 300).
X
Insert the ball coupling horizontally into ball
coupling recess D in the direction of the
arrow until the holes in ball coupling

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

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 357).
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 hitch
as a result.
Load distribution on the bicycle rack
C
Distance in height between the center of gravity and the ball coupling
D
Distance to the rear between the center of gravity and the ball coupling

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 162).
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 375).X
Shift th e transmission to position ] .X
Turn th e fron t wheels toward s th e curb.X
Consult a qualified specialist workshop .252
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp lights up and th e red I (US A only)
or $ (Canada only) indicator lamp flashes .
It is no t possibl e to apply th e electric parking brak e manually.X
Shift th e transmission to position ] .X
Visit a qualified specialist workshop .
' (US A only)
M (Canada only)
Check Brake Fluid
Level There is no t enough brak e flui d in th e brak e flui d reservoir . In addition ,
th e ' (US A only) or M (Canada only) warning lamp lights up in
th e instrumen t cluste r and a warning tone sounds.
G WARNIN G
The braking effec t may be impaired.
There is a ris k of an accident.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. Do no t continu e drivin g
under any circumstances. X
Secur e th e vehicl e against rollin g away ( Y
page 161).X
Consult a qualified specialist workshop .X
Do no t add brak e fluid . This does no t correc t th e malfunction .
& Check Brake Pad Wea r The brak e pads/linings hav e reached their wear limit.
US A only: th e ' red brak e system warning lamp is lit while th e
engin e is running. X
Visit a qualified specialist workshop .
S Inoperative On e or mor e main features of th e mbrace system are malfunctioning .X
Visit a qualified specialist workshop .
Active Brake Assist
Functions Currently
Limite d See Opera‐
tor's Manual Active Brake Assis t wit h cross-traffic function is temporarily inopera-
tive.
Possibl e causes are: 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 .R
The system is outside th e operating temperature range.R
The on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Active Brake Assis t wit h cross-traffic function or PRE ‑ S AF E ®
PLU S is
functional 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.254
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
Active Brake Assist
Functions Currently
Limite d See Opera‐
tor's Manual Active Brake Assis t is unavailable due to a malfunction . Adaptive
Brake Assis t may also hav e failed.X
Visit a qualified specialist workshop immediately.
PRE-SAFE Inopera‐
tiv e See Operator' s
Manual Importan t function s of PRE-SAF E ®
hav e failed. Al l other occupant
safet y systems , e.g. air bags , remain available.X
Visit a qualified specialist workshop immediately.
Active Brake Assist
Functions Currently
Limite d See Opera‐
tor's Manual Active Brake Assis t or PRE ‑ SAFE ®
PLU S is temporarily inoperative.
Possibl e causes are: R
Function is impaire d due to heav y rain or snow.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 .R
Mercedes-AMG vehicles: ES P ®
is deactivated.R
The system is outside th e operating temperature range.R
The on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Active Brake Assis t or PRE ‑ SAFE ®
PLU S is operative 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.X
Mercedes-AMG vehicles: switch ES P ®
on again ( Y
page 71).
Active Brake Assist
Functions Limite d
See Operator' s Man ‐
ual Active Brake Assis t wit h cross-traffic function or PRE ‑ S AF E ®
PLU S is
no t available due to a malfunction .X
Visit a qualified specialist workshop immediately. Display messages 25 5
On-board computer and displays Z

Display messages
Possible causes/consequences and P Solutions
Radar Sensor s Dirty
See Operator' s Man ‐
ual The radar sensor system is malfunctioning .
Possibl e causes are: R
dir t on sensor sR
heav y rain or snow R
when drivin g on inter-urban roads without traffic or infrastructure,
e.g. in desert-like area s
At least on e drivin g system or drivin g safet y system is malfunctioning
or is temporarily unavailable :R
PRE-SAF E ®
PLU SR
Active Brake Assis tR
Active Lan e Keepin g Assis tR
Active Blind Spot Assis tR
Distanc e Pilo t DISTRONI C
If th e radar sensor system in fron t is dirty, Active Blind Spot Assis t will
no t perfor m a course-correcting brak e application .
A warning tone also sounds.
Once th e caus e of th e problem is no longer present, th e drivin g and
drive safet y systems will be available again . The display message dis-
appears.
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
Switc h off th e engine.X
Clean all sensor s ( Y
page 334).X
Restart th e engine.
The display message disappears.
u SRS Malfunction Ser ‐
vic e Required The restrain t system is malfunctioning .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.
Fo r further information about th e restrain t system, see ( Y
page 44) .
u Front Lef t Malfunc‐
tio n Servic e
Required or Front
Lef t Malfunction
Servic e Required The restrain t system has malfunctioned at th e fron t on th e lef t or right .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.256
Display messages
On-board computer and displays