2018 MERCEDES-BENZ GLS key battery

Problem
Possible causes/consequences and P Solutions
There is interference from a powerful source of radio waves. X
Unlock ( Y
page 84) or lock ( Y
page 84) the vehicle using the
mechanical key.
KEYLESS-GO is malfunctioning. X
Lock/unlock the vehicle using the remote control function of the
SmartKey. X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.
If the vehicle can also not be locked/unlocked using the remote con-
trol function: X
Unlock ( Y
page 84) or lock ( Y
page 84) the vehicle using the
mechanical key. X
Have the vehicle and SmartKey checked at a qualified specialist
workshop.
The engine cannot be
started using the Smart-
Key. The on-board voltage is too low. X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work: X
Check the starter battery and charge it if necessary ( Y
page 346).
or X
Jump-start the vehicle ( Y
page 346).
or X
Consult a qualified specialist workshop.
The engine cannot be
started using the Start/
Stop button. The Smart-
Key is in the vehicle. The vehicle is locked. X
Unlock the vehicle and try to start the vehicle again.
The SmartKey battery is discharged or nearly discharged. X
Check the SmartKey battery ( Y
page 80) and replace it if necessary
( Y
page 80).
If this does not work: X
Start your vehicle with the SmartKey in the ignition lock.
There is interference from a powerful source of radio waves. X
Start your vehicle with the SmartKey in the ignition lock.
You have lost a Smart-
Key. X
Have the SmartKey deactivated at a qualified specialist workshop. X
Report the loss immediately to the vehicle insurers. X
If necessary, have the locks changed as well.
You have lost the
mechanical key. X
Report the loss immediately to the vehicle insurers. X
If necessary, have the locks changed as well.82
SmartKey
Opening and closing

set correctly. If this is not the case, repeat the
steps above.
Problems with the side windows
G WARNING
If you close a side window again immediately after it has been blocked or reset, the side window
closes with increased or maximum force. The reversing feature is then not active. Parts of the
body could be trapped in the closing area in the process. This poses an increased risk of injury or
even fatal injury.
Make sure that no parts of the body are in the closing area. To stop the closing process, release
the switch or push the switch again to reopen the side window.
Problem
Possible causes/consequences and P Solutions
A side window cannot be
closed because it is
blocked by objects, e.g.
leaves in the window
guide. X
Remove the objects. X
Close the side window.
A side window cannot be
closed and you cannot
see the cause. If a side window is obstructed during closing and reopens again
slightly: X
Immediately after the window blocks, pull the corresponding switch
again until the side window has closed.
The side window is closed with increased force.
If a side window is obstructed again during closing and reopens again
slightly: X
Immediately after the window blocks, pull the corresponding switch
again until the side window has closed.
The side window is closed without the automatic reversing feature.
The side windows cannot
be opened or closed with
convenience opening. The SmartKey battery is discharged or nearly discharged. X
Check the SmartKey battery ( Y
page 80) and replace it if necessary
( Y
page 80).
If a side window will still not open or close due to a malfunction, consult a qualified specialist
workshop.
Sliding sunroof
Important safety notes
Your vehicle may be equipped with a sliding
sunroof or a panorama roof with power tilt/slid-
ing panel. In the following section, the term
"sliding sunroof" refers to both sliding sunroof
variants. G WARNING
While opening and closing the sliding sunroof,
body parts in close proximity could become
trapped. There is a risk of injury.
Make sure that no body parts are in close
proximity during the opening and closing pro-
cedures.92
Sliding sunroof
Opening and closing

Rear seat s
The three red indicator lamp s in th e butto n indicat e th e heating level you hav e selected.
The system automatically switches down from level 3 to level 2 after approximately eigh t minutes.
The system automatically switches down from level 2 to level 1 after approximately te n minutes.
The system automatically switches off approximately 35 minute s after it is set to level 1 .X
Turn th e SmartKey to position G or H in th e ignition loc k ( Y
page 140).X
To switch on: press butto n C repeatedly until th e desired heating level is set .X
To switch off : press butto n C repeatedly until all th e indicator lamp s go out .
i If th e battery voltag e is to o low, th e seat heating may switch off .
Activating/deactivating seat ventilation
The three blue indicator lamp s in th e buttons indicat e th e blowe r setting you hav e selected.X
Turn th e SmartKey to position G or H in th e ignition loc k ( Y
page 140).X
To switch on: press butto n C repeatedly until th e desired blowe r setting is set .X
To switch off : press butto n C repeatedly until all th e indicator lamp s go out .
i If th e battery voltag e is to o low, th e seat ventilation may switch off .
i You can open th e side windows and th e sliding sunroo f usin g th e "Convenience opening " feature
( Y
page 90) . The seat ventilation of th e driver' s seat automatically switches to th e highest level.Seats 107
Seats, steering wheel and mirrors Z

Problems with the seat heating or seat ventilation Problem
Possible causes/consequences and P Solutions
The seat heating or seat
ventilation has switched
off prematurely or can-
not be switched on. The on-board voltage is too low because too many electrical consum-
ers are switched on. X
Switch off electrical consumers that you do not need, such as the
rear window defroster or interior lighting.
Once the battery is sufficiently charged, the seat heating or seat
ventilation will switch back on automatically.
Steering wheel
Important safety notes
G WARNING
You could lose control of your vehicle if you do
the following while driving: R
adjust the driver's seat, head restraint,
steering wheel or mirrors R
fasten the seat belt
There is a risk of an accident.
Adjust the driver's seat, head restraint, steer-
ing wheel and mirror and fasten your seat belt
before starting the engine.
G WARNING
Children could injure themselves if they
adjust the steering wheel. There is a risk of
injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children unsupervised in the vehicle.
The electrically adjustable steering wheel can
still be adjusted when there is no SmartKey in
the ignition lock.
Adjusting the steering wheel man-
ually
G WARNING
If the steering wheel is unlocked while the
vehicle is in motion, it could change position
unexpectedly. This could cause you to lose control of the vehicle. There is a risk of an
accident.
Before starting off, make sure the steering
wheel is locked. Never unlock the steering
wheel while the vehicle is in motion.
C
Release lever D
Adjusts the steering wheel height

The daytime running lamps improve the visibility
of your vehicle during the day. To do this, the
daytime running lamps function must be
switched on using the on-board computer
( Y
page 243).
If the engine is running and you turn the light
switch to ` or X , the manual settings
take precedence over the daytime running
lamps.
Low-beam headlamps Even if the light sensor does not detect that it is
dark, the parking lamps and low-beam head-
lamps switch on when the ignition is switched on
and the light switch is set to the X position.
This is a particularly useful function in the event
of rain and fog. X
To switch on the low-beam headlamps:
turn the SmartKey to position H in the igni-
tion lock or start the engine. X
Turn the light switch to X .
The green X indicator lamp in the instru-
ment cluster lights up.
Rear fog lamp The rear fog lamp improves visibility of your
vehicle for the traffic behind in the event of thick
fog. Please take note of the country-specific
regulations for the use of rear fog lamps. X
To switch on the rear fog lamp: turn the
SmartKey to position H in the ignition lock or
start the engine. X
Turn the light switch to X or q .X
Press the ^ button.
The yellow ^ indicator lamp in the instru-
ment cluster lights up. X
To switch off the rear fog lamp: press the
^ button.
The yellow ^ indicator lamp in the instru-
ment cluster goes out.
Parking lamps
! If the battery charge is very low, the parking
lamps or standing lamps are automatically
switched off to enable the next engine start.
Always park your vehicle safely and in a well lit
area, in accordance with the relevant legal
stipulations. Avoid using the ` parking
lamps over a period of several hours. If pos-
sible, switch on the right-hand d or left-
hand c standing lamps. X
To switch on: turn the light switch to ` .
The green ` indicator lamp in the instru-
ment cluster lights up.
Standing lamps Switching on the standing lamps ensures the
corresponding side of t he vehicle is illuminated.X
To switch on the standing lamps: the
SmartKey should not be in the ignition lock or
in key position

Problems with the rear window defroster Problem
Possible causes/consequences and P Solutions
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 H in the igni-
tion lock ( Y
page 140).X
To activate: press the

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 ]
( Y
page 148).
The transmission position indicator on the
multifunction display shows ]
( Y
page 149).
i You can start the engine in transmission
position ] and \\ .
Starting procedure with the SmartKey X
To start a diesel engine: turn the SmartKey
to position H in the ignition lock
( Y
page 140).
The \( preglow indicator lamp in the instru-
ment cluster lights up. X
Turn the SmartKey to position I in the igni-
tion lock ( Y
page 140) and release it as soon
as the engine is running.
i Vehicles with a diesel engine: you can
start the engine without preglow if the engine
is warm.
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).
Vehicles with a gasoline engine: the engine
starts.
Vehicles with a diesel engine: preglow is
activated and 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 ] is selectedR
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 is sufficiently charged142
Driving
Driving and parking

X
Lift insert C up and out.X
To re-install the insert: place insert C into
the holder and press down on the right until it
engages.
Cigarette lighter
G WARNING
You can burn yourself if you touch the hot
heating element or the socket of the cigarette
lighter.
In addition, flammable materials can ignite if: R
the hot cigarette lighter falls R
a child holds the hot cigarette lighter to
objects, for example
There is a risk of fire and injury.
Always hold the cigarette lighter by the knob.
Always make sure that the cigarette lighter is
out of reach of children. Never leave children
unsupervised in the vehicle.
! The cigarette lighter in the center console in
the front compartment is not intended for
operating the tire inflation compressor.
Your attention must always be focused on the
traffic conditions. Only use the cigarette lighter
when road and traffic conditions permit. X
Turn the SmartKey to position H in the igni-
tion lock ( Y
page 140).X
To open: slide cover C to its foremost posi-
tion. X
Press in cigarette lighter D .
Cigarette lighter D will pop out automatically
when the heating element is red-hot. X
To close: pull cover C back as far as it will go. 12 V sockets
General notes X
Turn the SmartKey to position G in the igni-
tion lock ( Y
page 140).
With the exception of the socket in the front
center console, all sockets can be used for
accessories with a maximum current draw of
240 W (20 A). The socket in the front center
console can be used for accessories with a max-
imum current draw of 180 W( 15 A). Accessories
include such items as chargers for mobile
phones.
If you use the sockets for long periods when the
engine is switched off, the battery may dis-
charge.
i An emergency cut-out ensures that the on-
board voltage does not drop too low. If the on-
board voltage is too low, the power to the
sockets is automatically cut. This ensures
that there is sufficient power to start the
engine.
Socket in the front center console
! The socket is not suitable for operating the
tire inflation compressor. X
To open: slide the cover to its foremost posi-
tion. X
Lift up the cover of the socket. X
To close: pull the cover back as far as it will
go.
Socket in the rear compartment center
console Vehicles with the Rear Seat Entertainment Sys-
tem have two sockets in the center console in
the rear compartment. X
Lift up the cover of the socket.312
Features
Stowage and features