2018 MERCEDES-BENZ GLS brake light

Display messages
Possible causes/consequences and P Solutions
The yellow $ warning lamp lights up and th e red I (US A only)
or $ (Canada only) indicator lamp flashes .
It is no t possibl e to apply th e electric parking brak e manually.X
Shift th e transmission to position ] .X
Visit a qualified specialist workshop .
' (US A only)
M (Canada only)
Check Brake Fluid
Level There is no t enough brak e flui d in th e brak e flui d reservoir . In addition ,
th e ' (US A only) or M (Canada only) warning lamp lights up in
th e instrumen t cluste r and a warning tone sounds.
G WARNIN G
The braking effec t may be impaired.
There is a ris k of an accident.X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions. Do no t continu e drivin g
under any circumstances. X
Secur e th e vehicl e against rollin g away ( Y
page 161).X
Consult a qualified specialist workshop .X
Do no t add brak e fluid . This does no t correc t th e malfunction .
& Check Brake Pad Wea r The brak e pads/linings hav e reached their wear limit.
US A only: th e ' red brak e system warning lamp is lit while th e
engin e is running. X
Visit a qualified specialist workshop .
S Inoperative On e or mor e main features of th e mbrace system are malfunctioning .X
Visit a qualified specialist workshop .
Active Brake Assist
Functions Currently
Limite d See Opera‐
tor's Manual Active Brake Assis t wit h cross-traffic function is temporarily inopera-
tive.
Possibl e causes are: R
The radar sensor system is temporarily inoperative, e.g. due to
electromagneti c radiation emitted by nearby TV or radi o station s or
other source s of electromagneti c radiation .R
The system is outside th e operating temperature range.R
The on-boar d voltag e is to o low.
Whe n th e causes state d abov e no longer apply, th e display message
disappears.
Active Brake Assis t wit h cross-traffic function or PRE ‑ S AF E ®
PLU S is
functional again .
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 161).X
Restart th e engine.254
Display messages
On-board computer and displays

Display messages
Possible causes/consequences and P Solutions
Radar Sensor s Dirty
See Operator' s Man ‐
ual The radar sensor system is malfunctioning .
Possibl e causes are: R
dir t on sensor sR
heav y rain or snow R
when drivin g on inter-urban roads without traffic or infrastructure,
e.g. in desert-like area s
At least on e drivin g system or drivin g safet y system is malfunctioning
or is temporarily unavailable :R
PRE-SAF E ®
PLU SR
Active Brake Assis tR
Active Lan e Keepin g Assis tR
Active Blind Spot Assis tR
Distanc e Pilo t DISTRONI C
If th e radar sensor system in fron t is dirty, Active Blind Spot Assis t will
no t perfor m a course-correcting brak e application .
A warning tone also sounds.
Once th e caus e of th e problem is no longer present, th e drivin g and
drive safet y systems will be available again . The display message dis-
appears.
If th e display message does no t disappear :X
Pull ove r and stop th e vehicl e safely as soo n as possible, payin g
attention to roa d and traffic conditions.X
Secur e th e vehicl e against rollin g away ( Y
page 161).X
Switc h off th e engine.X
Clean all sensor s ( Y
page 334).X
Restart th e engine.
The display message disappears.
u SRS Malfunction Ser ‐
vic e Required The restrain t system is malfunctioning .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.
Fo r further information about th e restrain t system, see ( Y
page 44) .
u Front Lef t Malfunc‐
tio n Servic e
Required or Front
Lef t Malfunction
Servic e Required The restrain t system has malfunctioned at th e fron t on th e lef t or right .
The u warning lamp also lights up in th e instrumen t cluster.
G WARNIN G
The air bags or Emergency Tensioning Devices may either be triggered
unintentionally or, in th e event of an accident, may no t be triggered .
There is an increased ris k of injury.X
Visit a qualified specialist workshop immediately.256
Display messages
On-board computer and displays

To avoid damage to the vehicle, deactivate
Distance Pilot DISTRONIC and the HOLD
function in the following or similar situations: 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
Z .
The vehicle may otherwise be damaged.
! In car washes with a towing mechanism,
make sure that the automatic transmission is
in transmission position \\ ; 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
front-passenger door when the engine is
switched off. Otherwise, the automatic
transmission selects park position ] auto-
matically and locks the wheels. You can
prevent this by shifting the automatic trans-
mission to \\ beforehand.R
Vehicles with KEYLESS-GO:
Do not open the driver's door or front-
passenger door when the engine is
switched off. Otherwise, the automatic
transmission selects park position ] auto-
matically and locks the wheels.
Observe the following to make sure that the
automatic transmission stays in position \\ :X
Make sure the vehicle is stationary and the
ignition is switched off. X
Turn the SmartKey to position in the ignition
lock H ( Y
page 140).
Use the SmartKey instead of the Start/Stop
button on vehicles with KEYLESS-GO. X
Depress and hold the brake pedal. X
Shift the automatic transmission to position
\\ . X
Release the brake pedal. X
Release the electric parking brake. X
Switch off the ignition and leave the SmartKey
in the ignition lock.
You can wash the vehicle in an automatic car
wash from the very start.
If the vehicle is very dirty, pre-wash it before
cleaning it in an automatic car wash.
After using an automatic car wash, wipe off wax
from the windshield and the wiper blades. This
will prevent smears and reduce wiping noises
caused by residue on t he windshield.
Washing by hand In some countries, washing by hand is only
allowed at specially equipped washing bays.
Observe the legal requirements in all countries
concerned. X
Do not use hot water and do not wash the
vehicle in direct sunlight. X
Use a soft sponge to clean. X
Use a mild cleaning agent, such as a car
shampoo approved by Mercedes-Benz. X
Thoroughly hose down the vehicle with a gen-
tle jet of water. X
Do not point the water jet directly towards the
air inlets. X
Use plenty of water and rinse out the sponge
frequently. X
Rinse the vehicle with clean water and dry
thoroughly with a chamois. X
Do not let the cleaning agent dry on the paint-
work.
When using the vehicle in winter, remove all
traces of road salt deposits carefully and as
soon as possible.
Power washers
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. Care 331
Maintenance and care Z

! Always maintain a distance of at least
11.8 in (30 cm) between the vehicle and the
power washer nozzle. Information about the
correct distance is available from the equip-
ment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
Do not aim directly at any of the following: R
tires R
door gaps, roof gaps, joints, etc. R
electrical components R
battery R
plug-type couplings R
lights R
seals R
trim R
ventilation slots
Damaged seals or electrical components can
lead to leaks or failures.
! Vehicles with decorative foil: parts of your
vehicle are covered with decorative foil. Main-
tain a distance of at least 27.5 in (70 cm)
between the foil-wrapped parts of the vehicle
and the nozzle of the high pressure cleaner.
Information about the correct distance is
available from the equipment manufacturer.
Move the power washer nozzle around when
cleaning your vehicle.
The water temperature of the high-pressure
cleaner must not exceed 140 °F (60 °C).
Cleaning the paintwork
! Do not affix: R
stickers R
films R
magnetic plates or similar items
to painted surfaces. You could otherwise
damage the paintwork.
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. 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. X
Remove coolant, brake fluid, tree resin, oils,
fuels and greases by rubbing gently with a
cloth soaked in petroleum ether or lighter
fluid. X
Use tar remover to remove tar stains. X
Use silicone remover to remove wax.
If water no longer forms "beads" on the paint
surface, use the paint care products recommen-
ded and approved by Mercedes-Benz. This is the
case approximately every three to five months,
depending on the climate conditions and the
care product used.
If dirt has penetrated the paint surface or if the
paint has become dull, the paint cleaner recom-
mended and approved by Mercedes-Benz
should be used.
Do not use these care products in the sun or on
the hood while the hood is hot. X
Use a suitable touch-up stick, e.g. MB Touch-
Up Stick, to repair slight damage to the paint-
work quickly and provisionally.
Matte finish care
! Never polish the vehicle or the light alloy
wheels. Polishing causes the finish to shine.
! The following can give the paint a glossy
appearance and thus reduce the matt effect: R
Rubbing hard with unsuitable agents R
Washing the vehicle in direct sunlight
! Never use paint cleaner, buffing or polishing
products, or gloss preserver, e.g. wax, for the
purpose of paintwork care. These products
are only suitable for high-gloss surfaces. Their
use on vehicles with matte paintwork leads to
considerable surface damage or, more spe-
cifically, to shiny, spotted areas.
Always have paintwork repairs carried out at a
qualified specialist workshop.
! Only use automatic car washes which cor-
respond to the latest technological stand-
ards. Never use wash programs which finish
by treating the vehicle with hot wax.
Observe these notes if your vehicle has a clear
matte finish. This will help you to avoid damage
to the paintwork due to incorrect treatment.
These notes also apply to light alloy wheels with
a clear matt finish.332
Care
Maintenance and care

i Use only insect remover and car shampoo
from the range of recommended and
approved Mercedes-Benz care products.
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.
Always switch off the windshield wipers and
the ignition before cleaning the windshield or
wiper blades.
! Do not pull the wiper blade. Otherwise, the
wiper blade could be damaged.
! Do not clean wiper blades too often and do
not rub them too hard. Otherwise, the graph-
ite coating could be damaged. This could
cause wiper noise.
! Hold the wiper arm securely when folding
back. The windshield could be damaged if the
wiper arm smacks against it suddenly. X
Fold the windshield wiper arms away from the
windshield ( Y
page 123). X
Carefully clean the wiper blades with a damp
cloth. X
Fold the windshield wiper arms back again
before switching on the ignition.
Cleaning the exterior lighting
! Only use cleaning agents or cleaning cloths
which are suitable for plastic light lenses.
Unsuitable cleaning agents or cleaning cloths
could scratch or damage the plastic light len-
ses. X
Clean the plastic lenses of the exterior light-
ing using a wet sponge and a mild cleaning
agent, e. g. Mercedes-Benz car shampoo or
cleaning cloths. Care 333
Maintenance and care Z