2019 MERCEDES-BENZ GLS SUV park assist

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 charge state checked more
frequently if you use the vehicle mainly for short trips or if you leave it standing idle for a lengthyperiod. 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 electrical consumers.
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:
R set the clock (see the Digital Operator's Man-
ual)
On vehicles with a multimedia system and
navigation system, the clock is set automati-
cally.
R reset the function for automatically folding
the exterior mirrors in/out by folding the mir-
rors out once(Y page 111) Charging the 12 V battery
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
ventilation while charging and jump-starting.
Do not lean over a battery. 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 batter- ies. Wash away battery acid immediately with
plenty of clean water and seek medical atten-tion. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing 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.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
! Only charge the battery using the jump-
starting connection point.
The jump-starting connection point is in the
engine compartment (Y page 343).
X Open the hood.
X Connect the battery charger to the positive
terminal and ground point in the same order
as when connecting the donor battery in the
jump-starting procedure (Y page 343).
Keep away from fire and open flames. Do not
lean over a battery. Never charge the battery if it is still installed in the vehicle, unless you use a
battery charger which has been tested and
approved by Mercedes-Benz. A battery charger
unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. It permits the
charging of the battery in its installed position.
Contact an authorized Mercedes-Benz Center
for further information and availability. Read the battery charger's operating instructions before
charging the battery.
If, at low temperatures, the indicator lamps/
warning lamps in the instrument cluster do not
light up, it is highly likely that the discharged
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. 342
Battery (vehicle)Breakdown assistance

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

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

To avoid hazardous situations:
R never install snow chains to the front
wheels
R always install snow chains in pairs to the
rear wheels.
! Check the snow chains for damage before
mounting them. Damaged or worn snow
chains may snap and damage the following
components:
R wheel
R wheel housing
R wheel suspension
For this reason, you must use only snow
chains that are free of defects. Observe the
manufacturer's mounting instructions.
! You must drive at raised vehicle level (height
1) if snow chains have been installed. The
vehicle may otherwise be damaged.
! Vehicles with ADS (Adaptive Damping
System): do not use the sport mode when
driving with snow chains mounted. The vehi-
cle may otherwise be damaged.
For safety reasons, Mercedes-Benz recom-
mends that you only use snow chains that have been specially approved for your vehicle by
Mercedes-Benz, or are of a corresponding
standard of quality. For more information,
please contact a qualified specialist workshop.
Install the snow chains on all driven wheels for
maximum tractive power and driving stability. If
you own snow chains for two driven wheels only, install the snow chains to the wheels on the rear
axle. The vehicle then remains more stable
under braking.
If you intend to mount snow chains, please bear
the following points in mind:
R Snow chains may not be mounted on all
wheel/tire combinations. Permissible
wheel/tire combinations (Y page 377).
R Only use snow chains when driving on roads
completely covered by snow. Remove the
snow chains as soon as possible when you
come to a road that is not snow-covered.
R Local regulations may restrict the use of snow
chains. Observe the appropriate regulations if
you wish to mount snow chains. R
Do not exceed the maximum permissible
speed of 30 mph (50 km/h).
R When snow chains are installed, never use
Active Parking Assist (Y page 192) or the
Parking Package with rear view camera.
You may wish to deactivate ESP ®
(Y page 71)
when pulling away with snow chains mounted.
You can thereby allow the wheels to spin in a
controlled manner, achieving an increased driv-
ing force (cutting action).
Information about driving with an emergency
spare wheel (Y page 378). Tire pressure
Tire pressure specifications
Important safety notes G
WARNING
Underinflated or overinflated tires pose the
following risks:
R the tires may burst, especially as the load
and vehicle speed increase.
R the tires may wear excessively and/or
unevenly, which may greatly impair tire
traction.
R the driving characteristics, as well as steer-
ing and braking, may be greatly impaired.
There is a risk of an accident.
Follow recommended tire inflation pressures
and check the pressure of all the tires includ-
ing the spare wheel:
R monthly, at least
R if the load changes
R before beginning a long journey
R under different operating conditions, e.g.
off-road driving
If necessary, correct the tire pressure.
Details on tire pressure can be found at the fol-
lowing positions in the vehicle:
R Tire and Loading Information placard on the
B-pillar on the driver's side
R Table for tire pressure on the inside of the fuel
filler flap
The tire pressure monitor does not warn you of: Tire pressure
355Wheels and tires Z

PSI (pounds per square inch)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire width
in percent.
Tire pressure
This is pressure inside the tire applying an out-
ward force to each square inch of the tire's sur-
face. The tire pressure is specified in pounds per
square inch (psi), in kilopascal (kPa) or in bar.
The tire pressure should only be corrected when
the tires are cold.
Cold tire pressure
The tires are cold:
R if the vehicle has been parked with the tires
out of direct sunlight for at least three hours
and
R if the vehicle has not been driven further than
1 mile (1.6 km)
Tread
The part of the tire that comes into contact with
the road.
BeadThe tire bead ensures that the tire sits securely
on the wheel. There are several steel wires in the
bead to prevent the tire from coming loose from the wheel rim.
Sidewall The part of the tire between the tread and the
bead.
Weight of optional extras The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number) This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er's identity code, tire size, tire type code and
the manufacturing date. Load bearing index
The load bearing index (also load index) is a code that contains the maximum load bearing capa-
city of a tire.
Traction
Traction is the result of friction between the tires and the road surface.
TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible
weight that the ball coupling of the trailer tow
hitch can support.
Treadwear indicators Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of 00CDin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in a vehicle at their designated seating positions.
Total load limit Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle. Changing a wheel
Flat tire
The "Breakdown assistance" section
(Y page 335) contains information and notes on
how to deal with a flat tire. Information on driv-
ing with MOExtended tires in the event of a flat
tire can be found under "MOExtended tires (tires with run-flat characteristics" (Y page 336).
Vehicles with an emergency spare wheel: in
the event of a flat tire, mount the emergency
spare wheel according to the description under "Mounting a wheel" (Y page 373). Rotating the wheels
G
WARNING
Rotating the front and rear wheels if the
wheels or tires have different dimensions may severely impair the driving characteristics.
The service brake or wheel suspension com- 372
Changing a wheelWheels and tires