2019 MERCEDES-BENZ GLS SUV Owner's Manual

Problems with the rear window defroster
Problem
Possible causes/consequences and
0050
0050Solutions The rear window
defroster has deactiva-
ted prematurely or can-
not be activated. The battery has not been sufficiently charged.
X Switch off any consumers that are not required, e.g. reading lamps,
interior lighting or the seat heating.
When the battery is sufficiently charged, the rear window defroster can be activated again. Switching air-recirculation mode
on/off
General notes You can deactivate the flow of fresh air if
unpleasant odors are entering the vehicle from
outside. The air already inside the vehicle will
then be recirculated.
If you switch on air-recirculation mode, the win-
dows can fog up more quickly, in particular at
low temperatures. Only use air-recirculation
mode briefly to prevent the windows from fog-
ging up.
Activating/deactivating X
Turn the SmartKey to position 0048in the igni-
tion lock (Y page 140).
X To activate: press the0089button.
The indicator lamp in the 0089button lights
up.
i In the event of high pollution levels (3-zone
automatic climate control only) or at high out-
side temperatures, air-recirculation mode is
automatically activated. When air-recircula-
tion mode is activated automatically, the indi-
cator lamp in the 0089button is not lit.
Outside air is added after about 30 minutes.
X To deactivate: press the0089button.
The indicator lamp in the 0089button goes
out.
i Air-recirculation mode deactivates auto-
matically:
R after approximately five minutes at outside
temperatures below approximately 41 ‡
(5 †)
R after approximately five minutes if cooling
with air dehumidification is deactivated
R after approximately 30 minutes at outside
temperatures above approximately 41 ‡ (5 †) if the "Cooling with air dehumidifi-
cation" function is activated Switching the residual heat on or off
General notes The residual heat function is only available on
vehicles for Canada.
It is possible to make use of the residual heat of
the engine to continue heating the stationary
vehicle for up to 30 minutes after the engine has been switched off. The heating time depends on
the set interior temperature.
Activating/deactivating X
To activate: press the004Bor0056 button.
The indicator lamp in the 004Bor0056 button
lights up.
i The blower will run at a low speed regardless
of the airflow setting.
i If you activate the residual heat function at
high temperatures, only the ventilation will be
activated. The blower runs at medium speed.
X To deactivate: press the004Bor0056 but-
ton.
The indicator lamp in the 004Bor0056 button
goes out.
Residual heat is deactivated automatically:
R after approximately 30 minutes
R when the ignition is switched on
R if the battery voltage drops Ionization
Ionization is used to purify the air in the vehicle interior and attain an improved interior climate. Operating the climate control systems
135Climate control

The ionization of the interior air is odorless and
cannot be perceived directly in the vehicle inte- rior.
You can switch ionization on and off via the mul-
timedia system (see the Digital Operator's Man-
ual).
Ionization can only be operated when the auto-
matic climate control is switched on. The side air vent on the driver's side must be open. Setting the air vents
Important safety notes
G
WARNING
Very hot or very cold air can flow from the air vents. This could result in burns or frostbite in the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air out-
lets. If necessary, redirect the airflow to
another area of the vehicle interior.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
R keep the air inlet grille on the hood and in the
engine compartment on the front-passenger
side free of blockages, such as ice, snow or
leaves.
R never cover the air vents or air intake grilles in
the vehicle interior.
i For virtually draft-free ventilation, adjust the
sliders of the air vents to the center position. Setting the center air vents
0043
Center air vent, left
0044 Center air vent, right
0087 Center vent thumbwheel, right
0085 Center vent thumbwheel, left
X To open or close: turn thumbwheels0087
and 0085to the left or right. Setting the side air vents
Example
0043
Side window defroster vent
0044 Side air vent, left
0087 Thumbwheel for side air vent
X To open or close: turn thumbwheel0087up or
down. Setting the glove box air vent
! Close the air vent when heating the vehicle.
At high outside temperatures, open the air
vent and activate the "cooling with air dehu-
midification" function. Otherwise, tempera-
ture-sensitive items stored in the glove box
could be damaged. 136
Setting the air ventsClimate control

0043
Air vent control
0044 Air vent
When the climate control system is activated,
the glove box can be ventilated, for instance to
cool its contents. The level of airflow depends on the airflow and air distribution settings.
X To open or close: turn thumbwheel0043to the
right or left. Setting the rear air vents
Setting the center vents in the rear com-
partment Example: center vents with rear control panel
0043
Rear-compartment air vent thumbwheel
0044 Rear-compartment air vent, right
0087 Rear control panel
0085 Rear-compartment air vent, left
X To open or close: turn thumbwheel0043up or
down. Setting the B-pillar air vent Second row of seats
0043
B-pillar air vent
0044 Thumbwheel for B-pillar air vent
X To open or close: turn thumbwheel0044to the
left or right. B-pillar air vent in the headliner
0043
B-pillar air vent
0044 Thumbwheel for B-pillar air vent
X To open or close: turn thumbwheel0044up or
down. Setting the air vents
137Climate control Z

Third row of seats
B-pillar air vent in the headliner
0043
B-pillar air vent
0044 Thumbwheel for B-pillar air vent
X To open or close: turn thumbwheel0044up or
down. 138
Setting the air ventsClimate control

Notes on breaking-in a new vehicle
Important safety notes
The sensor system of some driving and driving
safety systems adjusts automatically while a
certain distance is being driven after the vehicle has been delivered or after repairs. Full system
effectiveness is not reached until the end of this
teach-in procedure.
New and replaced brake pads and discs only
reach their optimum braking effect after several hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal. The first 1000 miles (1500 km)
The more you look after the engine when it is
new, the more satisfied you will be with its per-
formance in the future. R You should therefore drive at varying vehicle
and engine speeds for the first 1000 miles
(1500 km).
R Avoid heavy loads, e.g. driving at full throttle,
during this period.
R Change gear in good time, before the tach-
ometer needle is 00C3of the way to the red area
of the tachometer.
R Do not manually shift to a lower gear to brake
the vehicle.
R Try to avoid depressing the accelerator pedal
beyond the point of resistance (kickdown).
Additional breaking-in notes for Mercedes-AMG
vehicles:
R Do not drive faster than 85 mph (140 km/h)
for the first 1,000 miles (1,500 km).
R Only allow the engine to reach a maximum
engine speed of 4,500 rpm briefly.
R Change gear in good time.
R Ideally, for the first 1,000 miles (1,500 km),
drive in the Comfortdrive program.
After 1000 mile s(1500 km), you can increase
the engine speed gradually and accelerate the
vehicle to full speed.
You should also observe these notes on break-
ing in if the engine or parts of the drive train on your vehicle have been replaced.
Always observe the maximum permissible
speed. Driving
Important safety notes
G
WARNING
Objects in the driver's footwell can restrict the pedal travel or obstruct a depressed pedal.
The operating and road safety of the vehicle is
jeopardized. There is a risk of an accident.
Make sure that all objects in the vehicle are
stowed correctly, and that they cannot enter
the driver's footwell. Install the floormats
securely and as specified in order to ensure
sufficient clearance for the pedals. Do not use loose floormats and do not place floormats on
top of one another. G
WARNING
Unsuitable footwear can hinder correct usage of the pedals, e.g.:
R shoes with thick soles
R shoes with high heels
R slippers
There is a risk of an accident.
Wear suitable footwear to ensure correct
usage of the pedals. G
WARNING
If you switch off the ignition while driving,
safety-relevant functions are only available
with limitations, or not at all. This could affect, for example, the power steering and the brake
boosting effect. You will require considerably
more effort to steer and brake. There is a risk of an accident.
Do not switch off the ignition while driving. G
WARNING
If the parking brake has not been fully
released when driving, the parking brake can:
R overheat and cause a fire
R lose its hold function.
There is a risk of fire and an accident. Release
the parking brake fully before driving off. Driving
139Driving and pa rking Z

!
Do not warm up the engine while stationary.
Pull away immediately. Avoid high engine
speeds and full throttle until the engine has
reached its operating temperature.
In vehicles with automatic transmission,
engage positions P and R only when the vehi-
cle is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery roads.
You could otherwise damage the drive train.
! Mercedes-AMG vehicles:
at low engine oil
temperatures below 68 ‡ (+20 †), the max-
imum engine speed is restricted in order to
protect the engine. To protect the engine and
maintain smooth engine operation, avoid driv-
ing at full throttle when the engine is cold. Key positions
SmartKey 005A
To remove the SmartKey
0047 Power supply for some consumers, such as
the windshield wipers
0048 Ignition (power supply for all consumers)
and drive position
0049 To start the engine
i The SmartKey can be turned in the ignition
lock even if it is not the correct SmartKey for
the vehicle. The ignition is not switched on.
The engine cannot be started.
KEYLESS-GO General notes
Vehicles with KEYLESS-GO are equipped with a
SmartKey featuring an integrated KEYLESS-GO
function and a detachable Start/Stop button. A check which periodically establishes a radio
connection between the vehicle and the Smart-
Key determines whether a valid SmartKey is in
the vehicle. This occurs, for example, when
starting the engine.
When you insert the Start/Stop button into the ignition lock, the system needs approximately
two seconds recognition time. You can then usethe Start/Stop button.
Pressing the Start/Stop button several times in
succession corresponds to the different Smart-
Key positions in the ignition lock. This is only the
case if you are not depressing the brake pedal.
If you depress the brake pedal and press the
Start/Stop button, the engine starts immedi-
ately.
To start the vehicle without actively using the
SmartKey:
R the Start/Stop button must be inserted in the
ignition lock
R the SmartKey must be in the vehicle
R the vehicle must not be locked with the
SmartKey or KEYLESS-GO (Y page 78).
Do not keep the SmartKey:
R with electronic devices, e.g. a mobile phone
or another SmartKey
R with metallic objects, e.g. coins or metal foil
R inside metallic objects, e.g. a metal case
This can impair the functionality of the KEY-
LESS-GO key.
Do not keep the KEYLESS-GO key in the tem-
perature-controlled cup holder (Y page 304).
Otherwise, the KEYLESS-GO key will not be rec-
ognized.
If you lock the vehicle with the SmartKey remote
control or with KEYLESS-GO, after a short time:
R you will not be able to switch on the ignition
with the Start/Stop button
R you will not be able to start the engine with the
Start/Stop button until the vehicle is
unlocked again
If you lock the vehicle centrally using the button
on the front door (Y page 83), you can continue
to start the engine with the Start/Stop button.
The engine can be switched off while the vehicle
is in motion by pressing and holding the Start/
Stop button for three seconds. This function
operates independently of the ECO start/stop
automatic engine switch-off function. 140
DrivingDriving and parking

Key positions with KEYLESS-GO
0043
Start/Stop button
0044 Ignition lock
As soon as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. Further information on situations where an
indicator lamp either fails to go out after starting the engine or lights up while driving
(Y page 276).
If Start/Stop button 0043has not yet been
pressed, this corresponds to the SmartKey
being removed from the ignition.
X To switch on the power supply: press
Start/Stop button 0043once.
The power supply is switched on. You can now activate the windshield wipers, for example.
The power supply is switched off again if:
R the driver's door is opened and
R you press Start/Stop 0043button twice when in
this position
X To switch on the ignition: press Start/Stop
button 0043twice.
The ignition is switched on.
If you press Start/Stop button 0043once when
in this position, the ignition is deactivated
again.
Removing the Start/Stop button
You can remove the Start/Stop button from the
ignition lock and start the vehicle as normal
using the SmartKey.
It is possible to switch between KEYLESS-GO
mode and key operation only when the trans-
mission is in position 005D.
X Remove Start/Stop button 0043from ignition
lock 0044. You do not have to remove the Start/Stop but-
ton from the ignition lock when you leave the
vehicle. You should, however, always take the
SmartKey with you when leaving the vehicle. As
long as the SmartKey is in the vehicle:
R the vehicle can be started using the Start/
Stop button
R the electrically powered equipment can be
operated Starting the engine
Important safety notes G
WARNING
If children are left unsupervised in the vehicle, they could:
R open the doors, thus endangering other
people or road users.
R get out and disrupt traffic.
R operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they:
R release the parking brake.
R shifting the automatic transmission out of
park position P
R Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children. G
DANGER
Combustion engines emit poisonous exhaust
gases such as carbon monoxide. Inhaling
these exhaust gases is hazardous to health
and can result in poisoning. There is a risk of
fatal injury. Therefore, never leave the engine running an enclosed space without adequate
ventilation. Driving
141Driving and pa rking Z

G
WARNING
Flammable materials introduced through
environmental influence or by animals can
ignite if in contact with the exhaust system or parts of the engine that heat up. There is a risk
of fire.
Carry out regular checks to make sure that
there are no flammable foreign materials in
the engine compartment or in the exhaust
system.
General notes Vehicles with a gasoline engine:
the catalytic
converter is preheated for up to 30 seconds
after a cold start. The sound of the engine may
change during this time.
Automatic transmission X
Shift the transmission to position 005D
(Y page 148).
The transmission position indicator on the
multifunction display shows 005D
(Y page 149).
i You can start the engine in transmission
position 005Dand 005C.
Starting procedure with the SmartKey X
Turn the SmartKey to position 0049in the igni-
tion lock (Y page 140) and release it as soon
as the engine is running.
Using KEYLESS-GO to start the engine The Start/Stop button can be used to start the
vehicle without inserting the SmartKey into the
ignition lock. The Start/Stop button must be
inserted in the ignition lock and the SmartKey
must be in the vehicle. This mode for starting the engine operates independently of the ECO
start/stop automatic engine start function.
X Depress the brake pedal and keep it
depressed.
X Press the Start/Stop button once
(Y page 140).
The engine starts. Starting procedure via smartphone Observe the important safety notes on starting
the engine (Y
page 141).
You can also start your engine via your smart-
phone from outside the vehicle. In this case, the previously selected climate control setting is
activated. In this way you can cool or heat the
interior of the vehicle before starting the jour-
ney.
Only start the engine via your smartphone if it is
safe to start and run the engine where your vehi-
cle is parked.
Observe the legal stipulations in the area where your vehicle is parked. Engine start via smart-
phone may be limited to certain countries or
regions.
You can execute a maximum of two consecutive
starting attempts via your smartphone. If you
insert the SmartKey into the ignition lock, you
can carry out two more starting attempts.
Once you have started the engine, you can
switch the engine off via your smartphone at any
time.
You can only start the engine via your smart-
phone if:
R the SmartKey is in the ignition lock
R park position 005Dis selected
R the accelerator pedal is not depressed
R the anti-theft alarm system is not activated
R the panic alarm is not activated
R the hazard warning lamps are switched off
R the hood is closed
R the doors are closed and locked
R the windows and sliding sunroof are closed
Also make sure that:
R the fuel tank is sufficiently filled
R the starter battery has been sufficiently
charged G
WARNING
Limbs could be crushed or trapped if the
engine is started unintentionally during ser-
vice or maintenance work. There is a risk of
injury.
Always secure the engine against uninten-
tional starting before carrying out mainte-
nance or repair work. 142
DrivingDriving and parking