warning MERCEDES-BENZ GLS 2018 Service Manual

Off-road ABS An ABS system specifically suited to off-road
terrain is activated automatically once the off-
road program is activated on: R
Vehicles without the Offroad Engineering
package ( Y
page 219)R
Vehicles with the Off-Road Engineering pack-
age ( Y
page 220)
At speeds below 20 mph (30 km/h), the front
wheels lock cyclically during braking. The dig-
ging-in effect achieved in the process reduces
the stopping distance on off-road terrain. This
limits steering capability.
BAS (Brake Assist System)
General information BAS operates in emergency braking situations.
If you depress the brake pedal quickly, BAS
automatically boosts the braking force, thus
shortening the stopping distance.
Important safety notes
i Observe the "Important safety notes" sec-
tion ( Y
page 66).
G WARNING
If BAS is malfunctioning, the braking distance
in an emergency braking situation is
increased. There is a risk of an accident.
In an emergency braking situation, depress
the brake pedal with full force. ABS prevents
the wheels from locking.
Braking X
Keep the brake pedal firmly depressed until
the emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will function as usual once you
release the brake pedal. BAS is deactivated. Active Brake Assist
General information
i Observe the "Important safety notes" sec-
tion ( Y
page 66).
Active Brake Assist consists of a distance warn-
ing function with an autonomous braking func-
tion and situation-dependent braking assis-
tance
Active Brake Assist can help you to minimize the
risk of a collision with the vehicle traveling in
front or reduce the effects of such a collision.
If Active Brake Assist detects that there is a risk
of collision, you will be warned visually and
acoustically. If you do not react to the visual and
audible collision warning, autonomous braking
can be initiated in critical situations. If you apply
the brake yourself in a critical situation, Adap-
tive Brake Assist supports you with situation-
dependent braking assistance.
Active Brake Assist is only available in certain
countries.
Important safety notes In particular, the detection of obstacles can be
impaired if: R
there is dirt on the sensors or anything else
covering the sensors R
there is snow or heavy rain R
there is interference by other radar sources R
there are strong radar reflections, for exam-
ple in parking garages R
a narrow vehicle is traveling in front, e.g. a
motorbike R
a vehicle is traveling in front on a different line R
you are driving a new vehicle or servicing on
the Active Brake Assist system has just been
carried out
Observe the notes in the section on breaking-
in ( Y
page 139).
Following damage to the front end of the vehicle,
have the configuration and operation of the
radar sensor checked at a qualified specialist
workshop. This also applies to collisions at slow
speeds where there is no visible damage to the
front of the vehicle.Driving safety systems 67
Safety Z

Activating/deactivating Active Brake Assis t is automatically active after
switching on th e ignition .
You can activat e or deactivat e Active Brake
Assis t ( Y
page 242) in th e on-board computer.
When deactivated, th e distanc e warning func-
tion and th e autonomous braking function are
also deactivated.
If Active Brake Assis t is deactivated, th e

passenger protection measures (PRE-SAFE ®
)
are activated simultaneously ( Y
page 58).
Situation-dependent braking assis-
tance General information
i Observe the "Important safety notes" sec-
tion ( Y
page 66).
With the help of the radar sensor system, Adap-
tive Brake Assist can detect obstacles that are in
the path of your vehicle for an extended period
of time.
If Adaptive Brake Assist detects a risk of colli-
sion with the vehicle in front, it calculates the
brake pressure necessary to avoid a collision. If
you apply the brakes forcefully, situation-
dependent braking assistance adapts to the sit-
uation and automatically increases the brake
pressure to a degree appropriate to the traffic
situation.
Situation-dependent braking assistance pro-
vides braking assistance in hazardous situations
at speeds above 4 mph (7 km/h). It uses radar
sensor technology to assess the traffic situa-
tion.
Situation-dependent braking assistance is capa-
ble of reacting to moving objects that have
already been detected as such at least once
over the period of observation, up to vehicle
speeds of around 155 mph (250 km/h).
Situation-dependent braking assistance reacts
to stationary obstacles up to a speed of approx-
imately 44 mph (70 km/ h) .
If situation-dependent braking assistance
demands particularly high brake pressure, pre-
ventative passenger protection measures (PRE-
SAFE ®
) are triggered simultaneously
( Y
page 58). X
Keep the brake pedal depressed until the
emergency braking situation is over.
ABS prevents the wheels from locking.
The brakes will work normally again if: R
you release the brake pedal. R
there is no longer any danger of a collision. R
no obstacle is detected in front of your vehi-
cle.
Situation-dependent braking assistance is then
deactivated. Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems ( Y
page 66).
G WARNING
Adaptive Brake Assist cannot always clearly
identify objects and complex traffic situa-
tions.
In such cases, Adaptive Brake Assist might: R
intervene unnecessarily R
not intervene
There is a risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake. Terminate the
intervention in a non-critical driving situation.
G WARNING
Adaptive Brake Assist does not react: R
to people or animals R
to oncoming vehicles R
to crossing traffic R
when cornering
As a result, Adaptive Brake Assist may not
intervene in all critical conditions. There is a
risk of an accident.
Always pay careful attention to the traffic sit-
uation and be ready to brake.
Due to the nature of the system, complex but
non-critical driving conditions may also cause
Active Brake Assist to intervene.
Even if Active Brake Assist is not available due to
a malfunction in the radar sensor system, the
brake system is still available with full brake
boosting effect and BAS.
ESP ®
(Electronic Stability Program)
General notes
i Observe the "Important safety notes" sec-
tion ( Y
page 66).
ESP ®
monitors driving stability and traction, i.e.
power transmission between the tires and the
road surface.Driving safety systems 69
Safety Z

If ESP ®
detects that the vehicle is deviating from
the direction desired by the driver, one or more
wheels are braked to stabilize the vehicle. The
engine output is also modified to keep the vehi-
cle on the desired course within physical limits.
ESP ®
assists the driver when pulling away on
wet or slippery roads. ESP ®
can also stabilize
the vehicle during braking.
ETS/4ETS (Electronic Traction System) 4ETS traction control is part of ESP ®
.
Traction control brakes the drive wheels indi-
vidually if they spin. This enables you to pull
away and accelerate on slippery surfaces, for
example if the road surface is slippery on one
side. In addition, more drive torque is transfer-
red to the wheel or wheels with traction.
Traction control remains active, even if you
deactivate ESP ®
.
In appropriate driving situations, activate the
offroad program: X
Vehicles without the Offroad Engineering
package ( Y
page 219)X
Vehicles with the Off-Road Engineering pack-
age ( Y
page 220)
Off-road 4ETS (Electronic Traction Sys-
tem) An ETS system specifically suited to off-road
terrain is activated automatically once an off-
road program is activated: R
Vehicles without the Offroad Engineering
package ( Y
page 219)R
Vehicles with the Off-Road Engineering pack-
age ( Y
page 220)
Important safety notes
G WARNING
If ESP ®
is malfunctioning, ESP ®
is unable to
stabilize the vehicle. Additionally, further driv-
ing safety systems are deactivated. This
increases the risk of skidding and an accident.
Drive on carefully. Have ESP ®
checked at a
qualified specialist workshop. ! Only operate the vehicle for a maximum of
ten seconds on a brake test dynamometer.
Switch off the ignition.
Application of the brakes by ESP ®
may oth-
erwise destroy the brake system.
! A function or performance test should only
be carried out on a two-axle dynamometer.
Before you operate the vehicle on such a
dynamometer, please consult a qualified
workshop. You could otherwise damage the
drive train or the brake system.
ESP ®
is only deactivated if the

Deactivating/activating ESP ®
Important safet y notes
i Observ e th e "Important safet y notes" sec -
tion ( Y
page 66).
You can selec t between th e followin g states of
ES P ®
: R
ES P ®
is activated.R
ES P ®
is deactivated.
G WARNING
If you deactivat e ES P ®
, ES P ®
no longer sta-
bilizes th e vehicle. There is an increase d ris k
of skidding and an accident.
Only deactivat e ES P ®
in th e situation s descri-
bed in th e following.
It may be bes t to deactivat e ES P ®
in th e follow -
in g situations: R
when usin g snow chain sR
in dee p snowR
on san d or grave l
Spinning th e wheels result s in a cutting action
whic h provides bette r grip.
i Activat e ES P ®
as soo n as th e situation s
described abov e no longer apply . ES P ®
will
otherwise no t be able to stabilize th e vehicle if
th e vehicle start s to skid or a whee l start s to
spin.
! Avoid spinnin g th e driven wheels fo r an
extended period wit h ES P ®
deactivated. You
could otherwise damage th e drivetrain .
Deactivating/activating ESP ® X
To deactivate : press butto n C .
The

wind driving assistance function integrated in
ESP ®
noticeably reduces these impairments.
ESP ®
intervenes automatically according to the
direction and intensity of the crosswinds affect-
ing your vehicle.
ESP ®
intervenes with stabilizing braking to
assist you in keeping the vehicle in the lane.
Crosswind Assist is active at vehicle speeds
above 50 mph (80 km/ h) when driving straight
ahead or cornering gently.
Important safety notes Crosswind Assist does not work if ESP ®
is
switched off or deactivated because of a mal-
function.
EBD (electronic brake force distribu-
tion)
General information EBD monitors and controls the brake pressure
on the rear wheels to improve driving stability
while braking.
Important safety notes
i Observe the "Important safety notes" sec-
tion for driving safety systems ( Y
page 66).
G WARNING
If EBD is malfunctioning, the rear wheels can
lock, e.g. under full braking. This increases the
risk of skidding and an accident.
You should therefore adapt your driving style
to the different handling characteristics. Have
the brake system checked at a qualified spe-
cialist workshop.
Observe information regarding indicator and
warning lamps ( Y
page 282) as well as display
messages ( Y
page 251).
ADAPTIVE BRAKE
ADAPTIVE BRAKE enhances braking safety and
offers increased braking comfort. In addition to
the braking function, ADAPTIVE BRAKE also has
the HOLD function ( Y
page 187) and hill start
assist ( Y
page 143). Active Brake Assist with cross-traffic
function
General information
i Pay attention to the important safety notes
in the "Driving safety systems" section
( Y
page 66).
Active Brake Assist with cross-traffic function
can help you to minimize the risk of a collision
with a vehicle in front or a pedestrian and reduce
the effects of such a collision. If the Active Brake
Assist with cross-traffic function detects a risk
of collision, you will be warned visually and
acoustically and, if necessary, your brake appli-
cation will be assisted according to the situa-
tion. If you do not react, the system can also
react by braking automatically. In the event of a
detected risk of collision due to crossing traffic,
you will also be visually and acoustically warned
as well as assisted by the brake boosting effect
according to the situation.
Active Brake Assist with cross-traffic function is
only available in vehicles with the Driving Assis-
tance Plus package.
For Active Brake Assist with cross-traffic func-
tion to assist you when driving, the radar sensor
system and the camera system must be opera-
tional.
If the radar sensor system or the camera system
is malfunctioning, Active Brake Assist with
cross-traffic function is restricted or no longer
available. The brake system is still available with
complete brake boosting effect and BAS.
The radar sensor system and camera system
help Active Brake Assist with cross-traffic func-
tion to detect obstacles that are in t he path of
your
vehicle for an extended period of time.
In addition, pedestrians in the path of your vehi-
cle can be detected.
Active Brake Assist with cross-traffic function
detects pedestrians using typical characteris-
tics such as body contours and the posture of a
person standing upright.
i Observe the restrictions described in the
"Important safety notes" section
( Y
page 73).72
Driving safety systems
Safety

Important safety notes
G WARNIN G
Active Brake Assist wit h cross-traffic function
will initially brak e your vehicl e by a partial
application of th e brakes if a danger of colli-
sion is detected. Ther e may be a collision
unless you brak e yourself . Even after subse-
quen t full application of th e brakes a collision
canno t always be avoided, particularly when
approachin g at to o high a speed. Ther e is a
ris k of an accident.
Always apply th e brakes yourself and tr y to
tak e evasive action , provide d it is saf e to do
so.
In th e event of a partial application of th e brakes,
th e vehicl e is braked wit h up to 50 % of th e full
braking pressure.
G WARNIN G
Active Brake Assist wit h cross-traffic function
canno t always clearly identify objects and
comple x traffic situations.
In suc h cases, Active Brake Assist wit h cross -
traffic function might :R
issu e an unnecessary warning or engageR
neither giv e a warning no r interven e
Ther e is a ris k of an accident.
Always pay particular attention to th e traffic
situation and be prepare d to brake, especially
if Active Brake Assist wit h cross-traffic func-
tion alerts you. Terminate th e intervention in a
non-critical driving situation .
G WARNIN G
Active Brake Assist wit h cross-traffic function
canno t always clearly identify people, partic-
ularly if they are moving . Active Brake Assist
wit h cross-traffic function canno t interven e in
these cases. Ther e is a ris k of an accident.
Always pay particular attention to th e traffic
situation and be prepare d to brake, especially
if Active Brake Assist wit h cross-traffic func-
tion alerts you. In order to maintai n th e appropriat e distanc e to
th e vehicl e in fron t and thus preven t a collision ,
you must apply th e brakes yourself .
G WARNIN G
Active Brake Assist wit h cross-traffic function
does no t react: R
to small people, e.g. children R
to animals R
to oncomin g vehicles R
when cornering
As a result , Active Brake Assist wit h cross -
traffic function may no t warn you or engage in
all critical situations. Ther e is a ris k of an acci-
dent.
Always pay careful attention to th e traffic sit -
uation and be read y to brake.
In th e event of snowfall or heav y rain , th e rec -
ognition can be impaired.
Recognition by th e radar sensor system is also
impaire d if: R
there is dirt on th e sensor s or anythin g else
covering th e sensor sR
there is interferenc e by other radar source sR
there are stron g radar reflections, for exam-
ple in parking garages R
a narrow vehicl e is traveling in front, e.g. a
motorbike R
a vehicl e is traveling in fron t on a differen t lin e
relative to th e center of your vehicl eR
vehicles quickly mov e int o th e radar sensor
system detection range
Recognition by th e camera system is also
impaire d in th e event of: R
dirt on th e camera or if th e camera is coveredR
glar e on th e camera system, e.g. from th e sun
bein g low in th e sk yR
darkness R
or if: -
pedestrian s mov e quickly, e.g. int o th e p at h
of th e vehicl e -
th e camera system no longer recognizes a
pedestrian as a person due to special cloth -
ing or other objects -
a pedestrian is concealed by other objects -
th e typical outlin e of a person is no t distin-
guishable from th e backgroun dDriving safety systems 73
Safety Z

SmartKey
Important safety notes
G WARNING
If children are left unsupervised in the vehicle,
they could: R
open the doors, thus endangering other
people or road users. R
get out and disrupt traffic. R
operate the vehicle's equipment.
Additionally, children could set the vehicle in
motion if, for example, they: R
release the parking brake. R
shifting the automatic transmission out of
park position PR
Start the engine.
There is a risk of an accident and injury.
When leaving the vehicle, always take the
SmartKey with you and lock the vehicle. Never
leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
G WARNING
If you attach heavy or large objects to the
SmartKey, the SmartKey could be uninten-
tionally turned in the ignition lock. This could
cause the engine to be switched off. There is a
risk of an accident.
Do not attach any heavy or large objects to the
SmartKey. Remove any bulky key rings before
inserting the SmartKey into the ignition lock.
! Keep the SmartKey away from strong mag-
netic fields. Otherwise, the remote control
function could be affected.
Strong magnetic fields can occur in the vicin-
ity of powerful electrical installations.
Do not keep the SmartKey: R
with electronic devices, e.g. a mobile phone
or another SmartKey. R
with metallic objects, e.g. coins or metal foil. R
inside metallic objects, e.g. a metal case.
This can affect the functionality of the Smart-
Key. Do not keep the KEYLESS-GO or KEYLESS-GO
Start function key in the temperature-controlled
cup holder. Otherwise, the KEYLESS-GO or KEY-
LESS-GO Start function key will not be detected.
Vehicles with KEYLESS-GO start function: do
not keep the SmartKey in the cargo compart-
ment. Otherwise, the SmartKey may not be
detected, e.g. when starting the engine using
the Start/Stop button.
SmartKey functions
C
7 Locks the vehicleD
T Opens/closes the tailgate

SmartKey battery
Important safety notes
G WARNING
Batteries contain toxic and corrosive substan-
ces. If batteries are swallowed, it can result in
severe health problems. There is a risk of fatal
injury.
Keep batteries out of the reach of children. If
a battery is swallowed, seek medical attention
immediately.
H Environmental note
Batteries contain dangerous
substances. It is against the
law to dispose of them with
the household rubbish. They
must be collected separately
and 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.
The SmartKey batteries contain perchlorate
material, which may require special handling
and regard for the environment. National guide-
lines must be observed during disposal. In Cal-
ifornia, see www.dtsc.ca.gov/
HazardousWaste/Perchlorate/index.cfm .
Mercedes-Benz recommends that you have the
batteries replaced at a qualified specialist work-
shop. Checking the battery X
Press the 7 or 6 button.
The battery is working properly if battery
check lamp C lights up briefly.
The battery is discharged if battery check
lamp C does not light up briefly. X
Change the battery ( Y
page 80).
If the SmartKey battery is checked within the
signal reception range of the vehicle, pressing
the 7 or 6 button: R
locks or R
unlocks the vehicle
i You can get a battery at any qualified spe-
cialist workshop.
Replacing the battery You require a CR 2025 3 V cell battery. X
Take the mechanical key out of the SmartKey
( Y
page 79).
X
Press mechanical key D into the SmartKey
opening in the direction of the arrow until bat-
tery compartment cover C opens. Do not
hold battery compartment cover C closed
while doing so. X
Remove battery compartment cover C .80
SmartKey
Opening and closing

Door s
Important safet y notes
G WARNING
If children are lef t unsupervised in th e vehicle,
they could: R
ope n th e doors , thus endangerin g other
people or road users. R
get out and disrup t traffic .R
operat e th e vehicle' s equipment.
Additionally, children could set th e vehicle in
motion if, fo r example, they:R
release th e parking brake .R
shiftin g th e automatic transmissio n out of
par k position PR
Start th e engine.
There is a ris k of an acciden t and injury.
Whe n leavin g th e vehicle, always take th e
SmartKey wit h you and loc k th e vehicle. Never
leav e children or animals unattended in th e
vehicle. Always keep th e SmartKey out of
reach of children .
Unlockin g an d opening doors from
th e insideYou can ope n a doo r from insid e th e vehicle
eve n if it has bee n locked. You can only ope n th e
rea r doors from insid e th e vehicle if they are no t
secure d by th e child-proof locks ( Y
page 65).
If th e vehicle has previously bee n locke d from
th e outside, opening a doo r from th e insid e will
trigger th e anti-thef t alar m system. Switc h of f
th e alar m ( Y
page 75). X
Front door: pull doo r handle D .
If th e doo r is locked, locking knob C pop s up.
The doo r is unlocke d and can be opened.X
Rea r door: pull doo r handle D .
If th e doo r is locked, locking knob C pop s up
and th e doo r unlocks .X
Pull doo r handle D again .
The doo r can be opened.
Centrally locking an d unlocking th e
vehicle from th e insideYou can centrall y loc k or unloc k th e vehicle from
th e inside. The buttons are located on bot h fron t
doors .
X
To unlock : press butto n C .X
To lock : press butto n D .
If th e front-passenger doo r is closed, th e vehi-
cl e locks .
Meanwhile, th e fue l filler flap will no t be locke d
or unlocked.
You canno t unloc k th e vehicle centrall y from th e
insid e if th e vehicle has bee n locke d from th e
outside.
You can ope n a fron t doo r from insid e th e vehi-
cl e eve n if it has bee n locked.
If a locke d doo r is opene d from th e inside, th e
previous unloc k status of th e vehicle will be
take n into consideration if: R
th e vehicle was locke d usin g th e locking but -
to n fo r th e central locking , orR
if th e vehicle was locke d automatically
The vehicle will be full y unlocke d if it had previ-
ousl y bee n full y unlocked. If only th e driver's
doo r had bee n previously unlocked, only th e
doo r whic h has bee n opene d from th e insid e is
unlocked. Doors 83
Opening and closing Z