2019 MERCEDES-BENZ GLS SUV brakes

Most U.S. states and all Canadian provinces
require by law:
R Safety chains between the towing vehicle and
the trailer. The chains should be cross-woundunder the trailer drawbar. They must be fas-
tened to the vehicle's trailer coupling, not to
the bumper or the axle.
Leave enough play in the chains to make tight
cornering possible.
R A separate brake system for certain types of
trailer.
R Safety switch for braked trailers. Check the
specific legal requirements applicable to your
state.
If the trailer becomes detached from the tow-
ing vehicle, the safety feature triggers the
trailer brakes. Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed restric-
tions. Make sure that your car/trailer combina- tion complies with the local regulations:
R in your place of residence
R in the location to which you are driving
The police and local authorities can provide reli-
able information.
Observe the following when towing a trailer:
R To gain driving experience and to become
accustomed to the new handling characteris-
tics, you should practice the following in a
traffic-free location:
- cornering
- stopping
- backing up
R Before driving, check:
- trailer tow hitch
- safety switch for braked trailers
- safety chains
- electrical connections
- lights
- wheels
R Adjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
R If the trailer has electronically controlled
brakes, pull away carefully. Brake manually using the brake controller and check whether
the brakes function correctly.
R Secure any objects on the trailer to prevent
the cargo from slipping when the vehicle is in
motion.
R When you couple up a trailer, check at regular
intervals that the load is firmly secured. If the trailer is equipped with trailer lights and
brakes, check the trailer to ensure that these
are working.
R Bear in mind that the handling will be less
stable when towing a trailer than when driving
without one. Avoid sudden steering move-
ments.
R The vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
R If possible, do not brake suddenly, but instead
depress the brake pedal moderately at first sothat the trailer can activate its brakes. Then
increase the pressure on the brake pedal.
R If the automatic transmission repeatedly
shifts between gears on uphill or downhill gra-
dients, shift to a lower gear using the left-hand
steering wheel paddle shifter.
A lower gear and lower speed reduce the risk of engine failure.
R When driving downhill, shift to a lower gear to
utilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if instal- led, the trailer brakes.
R If the coolant temperature increases dramat-
ically while the air-conditioning system is
switched on, switch off the air-conditioning
system.
Coolant heat can also be dissipated by open-
ing the windows and switching the ventilation blower and the interior temperature to the
highest level.
R When overtaking, pay particular attention to
the extended length of your vehicle/trailer
combination.
Due to the length of the vehicle/trailer com-
bination, you require additional road space in
relation to the vehicle you are overtaking
before you can change back to the original
lane. Towing a trailer
225Driving and parking Z

Display messages
Possible causes/consequences and
0050
0050Solutions Tire Pressure Moni‐
Tire Pressure Moni‐
tor Inoperative No tor Inoperative No
Wheel Sensors Wheel Sensors The wheels mounted do not have a suitable tire pressure sensor. The
tire pressure monitor is deactivated.
X Mount wheels with suitable tire pressure sensors.
The tire pressure monitor is activated automatically after driving for a few minutes. Tire
Tire
Press.
Press. Monitor
Monitor
Inoperative
Inoperative The tire pressure monitor is faulty.
X Visit a qualified specialist workshop. Vehicle
Display messages
Possible causes/consequences and
0050
0050Solutions Shift
Shift
to
to'P'
'P' or
or'N'
'N'
to Start Engine
to Start Engine You attempted to start the engine with the transmission in position
005E
or 005B.
X Shift the transmission to position 005Dor005C. Apply Brake to
Apply Brake to
Shift from 'P' Shift from 'P' You attempted to shift the transmission to position
005B,005Eor005C
without depressing the brake pedal.
X Depress the brake pedal. To
To
Deselect
Deselect P
Por
or N,
N,
Depress Brake and
Depress Brake and
Start Engine Start Engine You attempted to shift the transmission out of position
005Dor005C into
another transmission position with the engine switched off.
X Depress the brake pedal.
X Start the engine. Apply Brake to
Apply Brake to
Select R Select R You have attempted to shift from position
005Bto position 005Ewithout
applying the brakes.
X Depress the brake pedal.
X Shift the transmission to position 005E. Driver's Door Open
Driver's Door Open
& Transmission Not & Transmission Not
in P Risk of Vehi‐ in P Risk of Vehi‐
cle Rolling Away cle Rolling Away The driver's door is open or not fully closed and the transmission is in
position 005E,005Cor005B.
A warning tone also sounds.
G WARNING
The vehicle may roll away.
There is a risk of an accident.
X Shift the transmission to position 005D.
X Secure the vehicle against rolling away (Y page 158).
X Close the driver's door completely. Only Shift to 'P' Only Shift to 'P'
when when
Vehicle
Vehicle is
isSta‐
Sta‐
tionary
tionary The vehicle is moving.
X
Stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions.
X Shift the transmission to position 005D. 270
Display
messagesOn-board computer and displays

Driving abroad
An extensive Mercedes-Benz Service network is
also available in other countries. You can obtain further information from any authorized
Mercedes-Benz Center. Care
General notes
H
Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man- ner.
! When cleaning your car, do not use:
R dry, coarse or hard cloths
R abrasive cleaning agents
R solvents
R cleaning agents containing solvents
Do not scrub.
Do not touch the surfaces and films with hard
objects, e.g. rings or ice scrapers. Otherwise,
you may scratch or damage the surfaces and films.
! Do not park your vehicle for a long period of
time directly after cleaning, particularly after
cleaning the wheel rim with wheel cleaner.
Wheel cleaner can lead to the increased cor-
rosion of the brake discs and pads. Therefore,
drive for a few minutes after cleaning. By
heating up the brakes, the brake discs and
pads dry. The vehicle can then be parked for a long period of time.
Regular care of your vehicle is a condition for
retaining the quality in the long term.
Use care products and cleaning agents recom-
mended and approved by Mercedes-Benz. Washing the vehicle and cleaning the
paintwork
Automatic car wash G
WARNING
Braking efficiency is reduced after washing
the vehicle. There is a risk of an accident. After the vehicle has been washed, brake
carefully while paying attention to the traffic
conditions until full braking power is restored.
! Before driving into an automatic car wash,
make sure that it is suitable for the dimen-
sions of the vehicle. In particular, make sure
that:
R there is enough ground clearance between
the vehicle underbody and the guide rails of the automatic car wash.
R the clearance width of the automatic car
wash is sufficient, particularly the width of
the guide rails.
R you enter the automatic car wash straight
and in the center of the guide rails in order
to avoid damaging the tires or wheel rims.
Fold in the exterior mirrors before the vehicle
is washed. The exterior mirrors could other-
wise be damaged.
! When Active Distance Assist DISTRONIC or
the HOLD function is activated, the vehicle
brakes automatically in certain situations.
To avoid damage to the vehicle, deactivate
Active Distance Assist DISTRONIC and the
HOLD function in the following or similar sit-
uations:
R when towing the vehicle
R in the car wash
! Never clean your vehicle in a Touchless
Automatic Car Wash as these use special
cleaning agents. These cleaning agents can
damage the paintwork or plastic parts.
! Make sure that:
R the side windows and the sliding sunroof
are fully closed.
R that the blower of the ventilation/heating
system is switched off (OFF button has
been pressed).
R the windshield wiper switch is at position
005A.
The vehicle may otherwise be damaged.
! In car washes with a towing mechanism,
make sure that the automatic transmission is
in transmission position 005C; otherwise, the
vehicle could be damaged.
R Vehicles with a SmartKey:
Do not remove the SmartKey from the igni-
tion lock. Do not open the driver's door or 326
CareMaintenance and care

e.g. a car shampoo approved for Mercedes-
Benz.
X Dry vehicles covered with film using a soft,
absorbent cloth after every wash.
Water marks could otherwise form.
Scratches, corrosive deposits, areas affected by
corrosion and damage caused by inadequate
care cannot always be completely repaired. In
such cases, visit a qualified specialist workshop.
X Remove dirt immediately, where possible,
while avoiding rubbing too hard.
The decorative film may be irreparably dam-
aged.
X Soak insect remains with insect remover and
rinse off the treated areas afterwards.
X Soak bird droppings with water and rinse off
the treated areas afterwards.
The Paint Cleaner cleaning product, which has
been approved and recommended for
Mercedes-Benz, should be used when dirt has
penetrated the decorative film surface or the
decorative film has become dull.
The manufacturer can provide you with infor-
mation on special care and cleaning products.
Surfaces covered with a decorative film may,
once a decorative film has been removed, show visual differences from the surfaces that were
not protected by a decorative film.
i Have work or repairs on decorative film car-
ried out at a qualified specialist workshop.
Mercedes-Benz recommends that you use an authorized Mercedes-Benz Center for this
purpose. Cleaning the vehicle parts
Cleaning the wheels G
WARNING
The water jet from a circular jet nozzle (dirt
blasters) can cause invisible exterior damage to the tires or chassis components. Compo-
nents damaged in this way may fail unexpect-edly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced imme-
diately. !
Do not use acidic wheel cleaning products
to remove brake dust. This could damage
wheel bolts and brake components.
! Do not park your vehicle for a long period of
time directly after cleaning, particularly after
cleaning the wheel rim with wheel cleaner.
Wheel cleaner can lead to the increased cor-
rosion of the brake discs and pads. Therefore,
drive for a few minutes after cleaning. By
heating up the brakes, the brake discs and
pads dry. The vehicle can then be parked for a long period of time.
Cleaning the windows G
WARNING
You could become trapped by the windshield wipers if they start moving while cleaning the
windshield or wiper blades. There is a risk of
injury.
Always switch off the windshield wipers and
the ignition before cleaning the windshield or
wiper blades.
! Do not use dry cloths, abrasive products,
solvents or cleaning agents containing sol-
vents to clean the inside of the windows. Do
not touch the insides of the windows with
hard objects, e.g. an ice scraper or ring. There is otherwise a risk of damaging the windows.
! Clean the water drainage channels of the
windshield and the rear window at regular
intervals. Deposits such as leaves, petals and pollen may under certain circumstances pre-
vent water from draining away. This can lead
to corrosion damage and damage to elec-
tronic components.
X Clean the inside and outside of the windows
with a damp cloth and a cleaning product that
is recommended and approved by Mercedes-
Benz.
Cleaning wiper blades G
WARNING
You could become trapped by the windshield wipers if they start moving while cleaning the
windshield or wiper blades. There is a risk of
injury. Care
329Maintenance and care
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

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

Model MB-Freigabe or
MB-Approval All models
229.5, 229.6
Mercedes‑AMG vehicles
229.5
Mercedes-AMG vehicles:
only use SAE 0W-40
or SAE 5W-40 engine oils.
i MB approval is indicated on the oil contain-
ers.
Filling capacities The following values refer to an engine oil
change, including the oil filter.
Model Capacity
GLS 550 4MATIC
Mercedes‑AMG
vehicles
9.0 US qt (8.5
l) All ot
her models 7.4 US qt (7.0
l) Ad
ditives !
Do not use any additives in the engine oil.
This could damage the engine. Brake fluid
G
WARNING
The brake fluid constantly absorbs moisture
from the air. This lowers the boiling point of
the brake fluid. If the boiling point of the brake fluid is too low, vapor pockets may form in the brake system when the brakes are applied
hard. This would impair braking efficiency.
There is a risk of an accident.
You should have the brake fluid renewed at
the specified intervals.
Comply with the important safety notes for ser- vice products when handling brake fluid
(Y page 384).
Use only brake fluid approved for Mercedes-
Benz according to MB-Freigabeor MB-Approval
331.0.
Information about approved brake fluid can be
obtained at any qualified specialist workshop or on the Internet at
http://bevo.mercedes-benz.com.
i Have the brake fluid regularly replaced at a
qualified specialist workshop in accordance
with the replacement intervals and the
replacement confirmed in the service report. Coolant
Important safety notes G
WARNING
If antifreeze comes into contact with hot com- ponents in the engine compartment, it may
ignite. There is a risk of fire and injury.
Let the engine cool down before you add anti-
freeze. Make sure that antifreeze is not spilled
next to the filler neck. Thoroughly clean the
antifreeze from components before starting
the engine.
! Only add coolant that has been premixed
with the desired antifreeze protection. You
could otherwise damage the engine.
You can find additional notes on the coolant in
the following places:
R in the Mercedes-Benz Specifications for
Service Products, MB BeVo 310.1
- on the Internet at
http://bevo.mercedes-benz.com
- on the Mercedes-Benz BeVo app
R a qualified specialized workshop
! Always use a suitable coolant mixture, even
in countries where high temperatures prevail.
Otherwise, the engine cooling system is not
sufficiently protected from corrosion and
overheating.
i Have the coolant regularly replaced at a
qualified specialist workshop and the replace- ment confirmed in the service report.
Comply with the important safety notes for ser- vice products when handling coolant
(Y page 384). Service products and filling capacities
387Technical data Z