2019 MERCEDES-BENZ GLS SUV Owner's Manual

Replacing the 12 V battery
Observe the notes on the 12 V battery.
Mercedes-Benz recommends that you have the
12 V battery replaced at a qualified specialist
workshop, e.g. at an authorized Mercedes-Benz
Center.
If you want to replace the battery yourself,
observe the following notes:
R Always replace a defective battery with a bat-
tery which meets the specific requirements of
the vehicle.
The vehicle is equipped with an AGM (Absorb-
ent Glass Mat) technology battery. Full vehi-
cle functionality is only guaranteed with an AGM battery. For safety reasons, Mercedes-
Benz recommends that you only use batteries
which have been tested and approved for your
vehicle by Mercedes-Benz.
R Use detachable parts such as breather hoses,
angled connecting pieces or terminal covers
from the battery which is to be replaced.
R Make sure that the vent hose is always con-
nected to the original opening on the battery
side.
Install any existing or supplied stop plugs.
Otherwise, gases or battery acid could
escape.
R Make sure that the detachable parts are con-
nected again in the same way. Jump-starting
For the jump-starting procedure, use only the jump-starting connection point in the engine com-
partment, consisting of a positive terminal and a ground point. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with skin, eyes or clothing. Do not inhale any battery gases. Do not lean over the
battery. Keep children away from batteries. Wash away battery acid immediately with plenty of
clean water and seek medical attention. G
WARNING
During charging and jump-starting, explosive gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, open flames, creating sparks and smoking. Ensure there is sufficient ven-
tilation while charging and jump-starting. Do not lean over a battery. G
WARNING
During the charging process, a battery produces hydrogen gas. If a short circuit occurs or sparks
are created, the hydrogen gas can ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a connected battery does not come into contact with
vehicle parts.
R Never place metal objects or tools on a battery.
R It is important that you observe the described order of the battery terminals when connecting
and disconnecting a battery.
R When jump-starting, make sure that the battery poles with identical polarity are connected.
R It is particularly important to observe the described order when connecting and disconnecting
the jumper cables.
R Never connect or disconnect the battery terminals while the engine is running. Jump-starting
343Breakdown assistance Z

G
WARNING
A discharged battery can freeze at temperatures below freezing point. When jump-starting the
vehicle or charging the battery, gases can escape from the battery. There is a risk of an explosion.
Allow the frozen battery to thaw out before charging it or jump-starting.
! Vehicles with a gasoline engine:
avoid repeated and lengthy starting attempts. Otherwise, the
catalytic converter could be damaged by non-combusted fuel.
If the indicator/warning lamps do not light up at low temperatures, it is very likely that the dis-
charged battery has frozen. In this case you may neither jump-start the vehicle nor charge the
battery. The service life of a thawed-out battery may be shorter. The starting characteristics can be
impaired, particularly at low temperatures. Have the thawed-out battery checked at a qualified
specialist workshop.
Do not start the vehicle using a rapid charging device. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a donor battery using jumper cables.
Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a donor battery or a jump-starting device.
R Vehicles with a gasoline engine: only jump-start the vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Only jump-start from batteries with a 12 V voltage rating.
R Only use jumper cables which have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the battery slightly.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jumper cables are not damaged.
R Bare parts of the terminal clamp do not come into contact with other metal parts while the jumper
cables are connected to the battery.
R The jumper cables cannot come into contact with parts that can move when the engine is running,
such as the V-belt pulley or the fan.
X Secure the vehicle by applying the electric parking brake.
X Shift the transmission to position 005D.
X Make sure that the ignition is switched off. All indicator lamps in the instrument cluster must be
off. When using the SmartKey, turn the SmartKey to position 0092in the ignition lock and remove it
(Y page 140).
X Switch off all electrical consumers, e.g. rear window defroster, lighting, etc.
X Open the hood.
i Right-hand-drive vehicle:
the jump-starting connection points may be located on the other
side of the vehicle. 344
Jump-startingBreakdown assistance

Position number
0084identifies the charged battery of the other vehicle or an equivalent jump-starting
device.
X Slide cover 0043of positive terminal 0044in the direction of the arrow.
X Connect positive terminal 0044on your vehicle to positive terminal 0087of donor battery 0084using the
jumper cable, always begin with positive terminal 0044on your own vehicle first.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal 0085of donor battery 0084to ground point 0083of your vehicle using the
jumper cable, beginning with donor battery 0084first.
X Start the engine.
X Before disconnecting the jumper cables, let the engine run for several minutes.
X First, remove the jumper cables from ground point 0083and negative terminal 0085, then from pos-
itive terminal 0044and positive terminal 0087. Begin each time at the contacts on your own vehicle
first.
X Close cover 0043of positive terminal 0044after removing the jumper cables.
X Have the battery checked at a qualified specialist workshop.
Jump-starting is not considered to be a normal operating condition.
i Jumper cables and further information regarding jump-starting can be obtained at any qualified
specialist workshop. Jump-starting
345Breakdown assistance Z

Towing and tow-starting
Important safety notes
G
WARNING
Functions relevant to safety are restricted or
no longer available if:
R the engine is not running.
R the brake system or the power steering is
malfunctioning.
R there is a malfunction in the voltage supply
or the vehicle's electrical system.
If your vehicle is being towed, much more
force may be necessary to steer or brake.
There is a risk of an accident.
In such cases, use a tow bar. Before towing,
make sure that the steering moves freely. G
WARNING
When towing or tow-starting another vehicle
and its weight is greater than the permissible gross weight of your vehicle, the:
R the towing eye could detach itself
R the vehicle/trailer combination could roll-
over.
There is a risk of an accident.
When towing or tow-starting another vehicle,
its weight should not be greater than the per- missible gross weight of your vehicle.
Details on the permissible gross vehicle weight
of your vehicle can be found on the vehicle iden-
tification plate (Y page 383).
! When Active Brake Assist, Active Distance
Assist DISTRONIC or the HOLD function is
activated, the vehicle brakes automatically in
certain situations.
To avoid damage to the vehicle, deactivate
these systems in the following or similar sit-
uations:
R when towing the vehicle
R in the car wash
! Make sure that the electric parking brake is
released. If the electric parking brake is faulty,
visit a qualified specialist workshop. !
Only secure the tow rope or tow bar at the
towing eyes, or the trailer tow hitch, if availa-
ble. You could otherwise damage the vehicle.
! Observe the following points when towing
with a tow rope:
R Secure the tow rope on the same side on
both vehicles.
R Make sure that the tow rope is not longer
than legally permitted. Mark the tow rope in
the middle, e.g. with a white cloth
(11.8 x 11.8 in). This will make other road
users aware that a vehicle is being towed.
R Only secure the tow cable to the towing
eyes or, if available, to the trailer tow hitch.
R Observe the brake lamps of the towing
vehicle while driving. Always maintain a dis-
tance a distance so that the tow rope does not sag.
R Do not use steel cables or chains to tow
your vehicle. You could otherwise damage
the vehicle.
! Do not use the trailer tow hitch for recovery
or towing. Do not use the towing eye for
recovery. this could damage the vehicle. If in
doubt, have the vehicle recovered using a
crane.
! When towing, pull away slowly and
smoothly. Pull the towed vehicle as straight as possible and not at an acute angle. Excessive
tractive power could damage the vehicles.
When towing, it is preferable to use a rigid tow-
ing bar as opposed to a tow rope. A rigid towing bar helps to keep the tractive power low.
! When towing away vehicles with KEYLESS-
GO, use the key instead of the Start/Stop
button. The automatic transmission may oth-
erwise shift to position 005Dwhen you open the
driver's or front-passenger door, which could damage the transmission.
! Do not tow with sling-type equipment. This
could damage the vehicle.
! Vehicles with differential locks: make sure
the differential locks are in automatic mode.
When towing, the differential locks must not
be switched on. The transmission may other- wise be damaged.
! You may tow the vehicle for a maximum dis-
tance of 30 miles (50 kilometers). A towing 346
Towing and tow-startingBreakdown assistance

speed of 30 mph (50 km/h) must not be
exceeded.
For towing distances over 30 miles
(50 kilometers), the entire vehicle must be
raised and transported.
It is better to have the vehicle transported than
to have it towed away.
If the vehicle has suffered transmission damage, have it transported on a transporter or trailer.
The automatic transmission must be in position
005C when the vehicle is being towed.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the SmartKey to position 0048in
the ignition lock
R cannot release the electric parking brake
R cannot shift the automatic transmission to
position 005C
Disarm the automatic locking feature before the vehicle is towed (Y page 241). You could other-
wise be locked out when pushing or towing the
vehicle. Permitted towing methods
Mercedes-Benz recommends transporting your
vehicle in the case of a breakdown, rather than
towing it away.
When towing away, use a towing rope or a tow-
ing bar with both axles on the ground. Do not use any tow bar systems. Installing/removing the towing eye
Installing the towing eye The brackets for the screw-in towing eye are
located in the bumpers. They are at the front and
rear behind covers 00430044.
X Remove the towing eye from the vehicle tool
kit (Y page 335).
X To open the cover at the front: press the
mark on cover 0043inwards in the direction of
the arrow.
X To open the cover at the rear: insert a flat,
blunt object into the cutout and lever
cover 0044out of the bumper.
X Take cover 0043or0044 off the opening.
X Screw in the towing eye clockwise as far as it
will go and tighten it.
Removing the towing eye X
Unscrew and remove the towing eye.
X Position cover 0043or0044 in the bumper and
press the cover on until it engages.
X Place the towing eye in the vehicle tool kit. Towing a vehicle with both axles on
the ground
The automatic transmission shifts to position
005D automatically when you open the driver's or
front-passenger door or when you remove the
SmartKey from the ignition lock. Towing and tow-starting
347Breakdown assistance Z

In order to ensure that the automatic transmis-
sion stays in position 005Cwhen towing away the
vehicle, you must observe the following points:
X Make sure that the vehicle is stationary.
X Turn the SmartKey to position 0048in the igni-
tion lock.
X Depress and hold the brake pedal.
X Shift the automatic transmission to position
005C.
X Leave the SmartKey in position 0048in the igni-
tion lock.
X Release the brake pedal.
X Release the electric parking brake.
X Switch on the hazard warning lamps
(Y page 117).
In order to signal a change of direction when
towing the vehicle with the hazard warning
lamps switched on, use the combination switch as usual. In this case, only the indicator lamps
for the direction of travel flash. After resetting
the combination switch, the hazard warning
lamp starts flashing again. Transporting the vehicle
4MATIC vehicles/vehicles with auto-
matic transmission !
When the vehicle is loaded for transport, the
front and rear axles must be stationary and on
the same transportation vehicle. Positioning
over the connection point of the transport
vehicle is not permitted. The drive train may
otherwise be damaged. All vehicles !
You may only secure the vehicle by the
wheels, not by parts of the vehicle such as
axle or steering components. Otherwise, the
vehicle could be damaged.
The towing eye can be used to pull the vehicle
onto a trailer or transporter for transporting pur-
poses.
X Turn the SmartKey to position 0048in the igni-
tion lock.
X Shift the automatic transmission to position
005C.
As soon as the vehicle has been loaded:
X Prevent the vehicle from rolling away by
applying the electric parking brake.
X Shift the automatic transmission to position
005D.
X Turn the SmartKey to position 0092in the igni-
tion lock and remove it.
X Secure the vehicle.
Securing the vehicle !
After loading, the vehicle must be secured at
all four wheels. Otherwise, the vehicle could
be damaged.
A minimum distance of 8 in (20 cm) up and
4 in (10 cm) down must be maintained to the transport platform.
X Secure all four wheels after loading the vehi-
cle.
Vehicles with ADS PLUS (Adaptive
Damping System PLUS) Important safety notes
G
WARNING
The weaker damping forces of the vehicle to
be transported can cause the vehicle/trailer
combination to swing.
As a result, when transporting vehicles with
Adaptive Damping System PLUS, the vehicle/ trailer combination may start to skid. Conse-
quently, you could lose control of the vehicle.
There is a risk of accident and injury. 348
Towing and tow-startingBreakdown assistance

When transporting, make sure that:
R the vehicle is has been loaded onto the
transporter correctly
R the vehicle is secured at all four wheels with
suitable tensioning straps
R you do not exceed the maximum permissi-
ble speed of 35 mph (60 km/h)
Securing the vehicle ! After loading, the vehicle must be secured at
all four wheels. Otherwise, the vehicle could
be damaged.
A minimum distance of 8 in (20 cm) up and
4 in (10 cm) down must be maintained to the
transport platform.
X Secure all four wheels after loading the vehi-
cle. Information on 4MATIC vehicles
! Vehicles with 4MATIC must not be towed
with either the front or the rear axle raised, as
doing so will damage the transmission.
Vehicles with 4MATIC may either be towed away with both axles on the ground or be loaded up
and transported.
If the vehicle's transmission, front, or rear axle is
damaged, have the vehicle transported on a
truck or trailer.
In the event of damage to the electrical sys-
tem: if the battery is defective, the automatic
transmission will be locked in position 005D. To
shift the automatic transmission to position 005C,
you must provide power to the vehicle's on-
board electrical system in the same way as
when jump-starting (Y page 343).
Have the vehicle transported on a transporter or
trailer. Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission must
not be tow-started. You could otherwise dam- age the automatic transmission.
You can find information on "Jump-starting"
under (Y page 343). Fuses
Important safety notes
G
WARNING
If you manipulate or bridge a faulty fuse or if
you replace it with a fuse with a higher amper- age, the electric cables could be overloaded.
This could result in a fire. There is a risk of an
accident and injury.
Always replace faulty fuses with the specified
new fuses having the correct amperage.
! For the fuse boxes in the engine compart-
ment and under the rear bench seat, only use fuses with the suffix "S". Otherwise, compo-
nents or systems could be damaged.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it is
lying correctly on the fuse box. Moisture seep-
ing in or dirt could otherwise impair the oper- ation of the fuses.
The fuses in your vehicle serve to close down
faulty circuits. If a fuse blows, all the compo-
nents on the circuit and their functions stop
operating.
Blown fuses must be replaced with fuses of the
same rating, which you can recognize by the
color and value. The fuse ratings are listed in the fuse allocation chart.
The fuse allocation chart is located in the fuse
box under the rear bench seat (Y page 350).
If a newly inserted fuse also blows, have the
cause traced and rectified at a qualified special- ist workshop, e.g. an authorized Mercedes-Benz
Center. Before changing a fuse
Observe the important safety notes
(Y page 349)
X Switch off the engine.
X Switch off all electrical consumers. Fuses
349Breakdown assistance Z

X
Remove the SmartKey from the ignition lock.
Or, on vehicles with KEYLESS-GO start function
or KEYLESS‑GO:
X Open the driver's door.
The vehicle electronics are now in key posi-
tion 0092. This is the same as the SmartKey
having been removed.
The driver’s door can be closed again.
X Secure the vehicle against rolling away
(Y page 158).
All indicator lamps in the instrument cluster
must be off.
The fuses are located in various fuse boxes:
R Fuse box on the front-passenger side of the
dashboard
R Fuse box in the engine compartment on the
right-hand side of the vehicle, when viewed in
the direction of travel
R Fuse box under the rear bench seat Dashboard fuse box
! Do not use a pointed object such as a screw-
driver to open the cover in the dashboard. You
could damage the dashboard or the cover.
Mercedes-Benz recommends that you have this work performed at a qualified specialist work-
shop, e.g. at an authorized Mercedes-Benz Cen-
ter. X
Open the front-passenger door.
X To open: pull cover 0043outwards in the direc-
tion of the arrow and remove it.
X To close: clip in cover 0043on the front of the
dashboard.
X Fold cover 0043inwards until it engages. Fuse box in the engine compartment
G
WARNING
When the hood is open and the windshield
wipers are set in motion, you can be injured by the wiper linkage. There is a risk of injury.
Always switch off the windshield wipers and
the ignition before opening the hood. X
Open the hood (Y page 321).
X Use a dry cloth to remove any moisture from
the fuse box.
X To open: open clamps 0044.
X Fold up cover 0043in the direction of the arrow
and remove it.
X To close: check whether the seal is seated
correctly in cover 0043.
X Insert cover 0043at the side of the fuse box into
the retainers.
X Fold down cover 0043and close clamps 0044.
X Close the hood. Fuse box under the rear bench seat350
FusesBreakdown assistance