2018 MERCEDES-BENZ GLS SUV key battery

Problems with the rear window defroster
ProblemPossible causes/consequences andMSolutions
The rear window
defroster has deactiva-
ted prematurely or can-
not be activated.The battery has not been sufficiently charged.
XSwitch 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
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 140).
XTo activate: press thedbutton.
The indicator lamp in the dbutton lights
up.
iIn 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 dbutton is not lit.
Outside air is added after about 30 minutes.
XTo deactivate: press thedbutton.
The indicator lamp in the dbutton goes
out.
iAir-recirculation mode deactivates auto-
matically:
Rafter approximately five minutes at outside
temperatures below approximately 41 ‡
(5 †)
Rafter approximately five minutes if cooling
with air dehumidification is deactivated
Rafter 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
XTo activate: press theÌorÁ button.
The indicator lamp in the ÌorÁ button
lights up.
iThe blower will run at a low speed regardless
of the airflow setting.
iIf you activate the residual heat function at
high temperatures, only the ventilation will be
activated. The blower runs at medium speed.
XTo deactivate: press theÌorÁ but-
ton.
The indicator lamp in the ÌorÁ button
goes out.
Residual heat is deactivated automatically:
Rafter approximately 30 minutes
Rwhen the ignition is switched on
Rif 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 systems135
Climate control

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
XShift the transmission to position j
(Ypage 148).
The transmission position indicator on the
multifunction display shows j
(
Ypage 149).
iYou can start the engine in transmission
position jand i.
Starting procedure with the SmartKey
XTo start a diesel engine: turn the SmartKey
to position 2in the ignition lock
(
Ypage 140).
The % preglow indicator lamp in the instru-
ment cluster lights up.
XTurn the SmartKey to position 3in the igni-
tion lock (Ypage 140) and release it as soon
as the engine is running.
iVehicles 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.
XDepress the brake pedal and keep it
depressed.
XPress the Start/Stop button once
(Ypage 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 (Ypage 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:
Rthe SmartKey is in the ignition lock
Rpark position jis selected
Rthe accelerator pedal is not depressed
Rthe anti-theft alarm system is not activated
Rthe panic alarm is not activated
Rthe hazard warning lamps are switched off
Rthe hood is closed
Rthe doors are closed and locked
Rthe windows and sliding sunroof are closed
Also make sure that:
Rthe fuel tank is sufficiently filled
Rthe starter battery is sufficiently charged
142Driving
Driving and parking

leave the vehicle when it is held by hill start
assist.
Hill start assist is not active if:
Ryou are pulling away on a level road or on a
downhill gradient.
Rthe transmission is in position N.
Rthe electric parking brake is applied.
RESP®is malfunctioning.
ECO start/stop function
Introduction
The ECO start/stop function switches the
engine off automatically if the vehicle is stopped
under certain conditions.
The engine starts automatically when the driver
wants to pull away again. The ECO start/stop
function thereby helps you to reduce the fuel
consumption and emissions of your vehicle.
Important safety notes
GWARNING
If the engine is switched off automatically and
you exit the vehicle, the engine is restarted
automatically. The vehicle may begin moving.
There is a risk of accident and injury.
If you wish to exit the vehicle, always turn off
the ignition and secure the vehicle against
rolling away.
General notes
:ECO start/stop display
The ECO start/stop function is activated when-
ever you start the engine using the SmartKey or the Start/Stop button.
If the engine has been switched off automati-
cally by the ECO start/stop function, the èECO symbol is shown in the multifunction dis-
play.
Mercedes-AMG vehicles: the ECO start/stop
function is only available in drive programs
Comfort andSlippery.
Automatic engine switch-off
If the vehicle is braked to a standstill in Dor N,
the ECO start/stop function switches off the
engine automatically.
The ECO start/stop function is operational
when:
Rthe indicator lamp in the ECO button is lit
green
Rthe Sport Plus orSport drive program is not
selected (Mercedes-AMG vehicles)
Rno Off-road program has been selected
Rthe outside temperature and the atmospheric
air pressure is within the range that is suitable
for the system
Rthe engine is at normal operating temperature
Rthe set temperature for the vehicle interior
has been reached
Rthe battery is sufficiently charged
Rthe system detects that the windshield is not
fogged up when the air-conditioning system is switched on
Rthe hood is closed
Rthe driver's door is closed and the driver's
seat belt is fastened
All of the vehicle's systems remain active when
the engine is stopped automatically.
The HOLD function can also be activated if the
engine has been switched off automatically. It is
then not necessary to continue applying the
brakes during the automatic stop phase. When
you depress the accelerator pedal, the engine
starts automatically and the braking effect of
the HOLD function is deactivated.
All vehicles (except Mercedes-AMG vehi-
cles): automatic engine switch-off can take
place a maximum of four times in a row (initial
stop, then three subsequent stops).
Mercedes-AMG vehicles: the number of con-
secutive automatic engine switch-offs is unlimi-
ted.
144Driving
Driving and parking

If indicator lamp;is off, the ECO start/stop
function has been deactivated manually or as
the result of a malfunction.
Problems with the engine
ProblemPossible causes/consequences and MSolutions
The engine does not
start. The starter motor
can be heard.RThere is a malfunction in the engine electronics.
RThere is a malfunction in the fuel supply.
Before attempting to start the engine again:
XTurn the SmartKey in the ignition lock back to position u.
or
XPress the Start/Stop button repeatedly until all indicator lamps in
the instrument cluster go out.
XTry to start the engine again (Ypage 141). Avoid excessively long
and frequent attempts to start the engine as these will drain the
battery.
If the engine does not start after several attempts:
XConsult a qualified specialist workshop.
The engine does not
start. You cannot hear
the starter motor.The on-board voltage is too low because the battery is too weak or
discharged.
XJump-start the vehicle (Ypage 346).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
XAllow the starter motor to cool down for approximately two minutes.
XTry to start the engine again.
If the engine still does not start:
XConsult a qualified specialist workshop.
Vehicles with a gasoline
engine:
The engine is not running
smoothly and is misfir-
ing.There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
XOnly depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it.
XHave the cause rectified immediately at a qualified specialist work-
shop.
The coolant temperature
gage shows a value
above 248 ‡ (120 †).The coolant level is too low. The coolant is too hot and the engine is no
longer being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant to
cool down.
XCheck the coolant level (Ypage 328). Observe the warning notes
as you do so and add coolant if necessary.
146Driving
Driving and parking

Problems with fuel and the fuel tank
ProblemPossible causes/consequences andMSolutions
Fuel is leaking from the
vehicle.GWARNING
The fuel line or the fuel tank is faulty.
Risk of explosion or fire.
XApply the electric parking brake.
XSwitch off the engine.
XRemove the SmartKey from the ignition lock.
or, on vehicles with KEYLESS‑GO:
XOpen the driver's door.
The vehicle electronics are now in key position u. This is the same
as the SmartKey having been removed.
XDo not restart the engine under any circumstances.
XConsult a qualified specialist workshop.
The engine does not
start.The fuel tank of a vehicle with a diesel engine has been run completely
dry.
XRefuel the vehicle with at least 5.3 US qt (5 liters) of diesel.
XTurn the ignition on for approximately ten seconds (Ypage 140).
XStart the engine continuously for up to ten seconds until it runs
smoothly.
If the engine does not start:
XTurn the ignition on again for approximately ten seconds
(Ypage 140).
XStart the engine again continuously for up to ten seconds until it
runs smoothly.
If the engine does not start after three attempts:
XConsult a qualified specialist workshop.
The fuel filler flap cannot
be opened.The fuel filler flap is not unlocked.
XUnlock the vehicle (Ypage 77).
The SmartKey battery is discharged or nearly discharged.
XUnlock the vehicle using the mechanical key (Ypage 79).
The fuel filler flap is unlocked, but the opening mechanism is jammed.
XConsult a qualified specialist workshop.
DEF (BlueTEC vehicles only)
General notes
To function properly, BlueTEC exhaust gas after-
treatment must be operated with the reducing
agent DEF. Adding DEF is one of the tasks per-
formed during maintenance. When the supply of DEF is almost used up, the
Check Additive See Operator's Manual
message is shown in the multifunction display.
If you drive the vehicle faster than 10 mph
(16 km/h), the
Check Additive See Opera‐
tor's Manualmessage goes out after approx-
imately one minute.
158Refueling
Driving and parking

Display messagesPossible causes/consequences andMSolutions
¥
Check Washer Fluid
The washer fluidlevel in th ewasher flui dreservoir has dropped belo w
th eminimum .
XAddwasher flui d (Ypage 329).
Wiper Malfunction‐ingThe windshield wiper sare malfunctioning .
XVisitaqualified specialist workshop .
Hazard WarningFlashers Malfunc‐tioning
The hazard warning lamp sare faulty.
XVisit aqualified specialist workshop .
SmartKey
Display messagesPossible causes/consequences and MSolutions
Â
KeyDoesNotBelongto Vehicl e
You haveput th ewrong SmartKey in th eignition lock.
XUse th ecorrec tSmartKey.
Â
Tak eYou rKey fro mIgnition
The SmartKey is in th eignition lock.
A warning tone also sounds.
XRemove th eSmartKey.
Â
Obtain aNew Key
The SmartKey needs to be replaced.
XVisit aqualified specialist workshop .
Â
ReplaceKey Batter y
The SmartKey battery is discharged.
XChange thebattery (Ypage 80) .
Â
Don't Forget You rKey
The SmartKey is notin th eignition lock. You hav eopened th edriver's
door wit hth eengin eswitched off .
A warning tone also sounds.
This display message is displayed for amaximum of 60 seconds and is
simply areminder.
XTak eth eSmartKey wit hyou when you leav eth evehicle.
Â
Key Not Detected(whit edisplay message )
The SmartKey is currentl yundetected.
XChange th elocation of th eSmartKey in th evehicle.
If th eSmartKey still canno tbe detected:
XOperat eth evehicl ewit hth eSmartKey in th eignition lock.
278Display messages
On-board computer and displays

XLift insert:up and out.
XTo re-install the insert: place insert:into
the holder and press down on the right until it
engages.
Cigarette lighter
GWARNING
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:
Rthe hot cigarette lighter falls
Ra 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.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 140).
XTo open: slide cover :to its foremost posi-
tion.
XPress in cigarette lighter ;.
Cigarette lighter ;will pop out automatically
when the heating element is red-hot.
XTo close: pull cover :back as far as it will go.
12 V sockets
General notes
XTurn the SmartKey to position 1in the igni-
tion lock (Ypage 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.
iAn 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.
XTo open: slide the cover to its foremost posi-
tion.
XLift up the cover of the socket.
XTo 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.
XLift up the cover of the socket.
312Features
Stowage and features

the household rubbish. They
must be collected separatelyand recycled to protect the
environment.
Dispose of batteries in an
environmentally friendly
manner. Take discharged
batteries to a qualified spe-
cialist workshop or a special
collection point for used bat-
teries.
!Have the battery regularly checked at a
qualified specialist workshop.
For more information, please contact a quali-
fied specialist workshop.
!Always have work on batteries carried out at
a qualified specialist workshop.
Should it, in exceptional circumstances, be
absolutely necessary to disconnect the 12-
volt battery yourself, please observe the fol-
lowing:
RSecure the vehicle to prevent it from rolling
away.
RSwitch off the ignition.
RDisconnect the negative terminal first and
then the positive terminal.
The transmission is locked in position j
after disconnecting the battery.
After the work has been done, install the bat-
tery and replace the cover of the positive ter-
minal clamp firmly.
Comply with safety precautions and take pro-
tective measures when handling batteries.
Risk of explosion.
Fire, open flames and smoking are
prohibited when handling the bat-
tery. Avoid creating sparks.
Battery acid is caustic. Avoid contact
with skin, eyes or clothing.
Wear suitable protective clothing,
especially gloves, apron and face-
guard. Rinse any acid spills immediately
with clear water. Contact a physician
if necessary.
Wear eye protection.
Keep children away.
Observe this Operator's Manual.
For safety reasons, Mercedes-Benz recom-
mends that you only use batteries which have
been tested and approved for your vehicle by
Mercedes-Benz. These batteries provide
increased impact protection to prevent vehicle
occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum
possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle.
In this case, have the battery disconnected at a
qualified specialist workshop. However, you can also charge the battery with a charger recom-
mended by Mercedes-Benz. Contact a qualified
specialist workshop for further information.
Have the battery condition of charge checked
more frequently if you use the vehicle mainly for
short trips or if you leave it standing idle for a
lengthy period. Consult a qualified specialist
workshop if you wish to leave your vehicle
parked for a long period of time.
Remove the SmartKey if you park the vehicle
and do not require any electrica l co
nsumers.
The vehicle will then use very little energy, thus conserving battery power.
If the power supply has been interrupted, e.g. if
you reconnect the battery, you will have to:
Rset the clock; see the Digital Operator's Man-
ual
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally.
Rreset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once (
Ypage 111)
Battery (vehicle)345
Breakdown assistance
Z