2018 MERCEDES-BENZ GLS SUV coolant temperature

Engine
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
;NThe yellow Check Engine warning lamp lights up while the engine is running.
There may be a malfunction, for example:
Rin the engine management
Rin the fuel injection system
Rin the exhaust system
Rin the ignition system (for vehicles with gasoline engines)
Rin the fuel system
The emission limit values may be exceeded and the engine may be in emergency
mode.
XVisit a qualified specialist workshop immediately.
Vehicles with a diesel engine: the fuel tank has been run dry (
Ypage 158).
XStart the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency running mode is
canceled. The vehicle need not be checked.
In some states, you must immediately visit a qualified specialist workshop as soon
as the yellow Check Engine warning lamp lights up. This is due to the legal require-
ments in effect in these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving.
8N The yellow reserve fuel warning lamp lights up while the engine is running.
The fuel level has dropped into the reserve range.
XRefuel at the nearest gas station.
8N The yellow reserve fuel warning lamp flashes while the vehicle is in motion.
In addition, the ;Check Engine warning lamp may light up.
The fuel filler cap is not closed correctly or the fuel system is leaking.
XCheck that the fuel filler cap is correctly closed.
XIf the fuel filler cap is not correctly closed: close the fuel filler cap.
XIf the fuel filler cap is closed:visit a qualified specialist workshop.
?NThe red coolant warning lamp lights up while the engine is running and the
coolant temperature gauge is at the start of the scale.
The temperature sensor for the coolant temperature gauge is malfunctioning.
The coolant temperature is no longer being monitored. There is a risk of engine
damage if the coolant temperature is too high.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 161).
XConsult a qualified specialist workshop.
288Warning and indicator lamps in the instrument cluster
On-board computer and displays

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
?NThe red coolant warning lamp comes on while the engine is running.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator may be blocked or
the electric engine radiator fan may be defective.
The coolant is too hot and the engine is no longer being cooled sufficiently.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 161).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 328).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
XDo not start the engine again until the coolant temperature is below 248 ‡
(120 †). Otherwise, the engine could be damaged.
XDrive to the nearest qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
?N The red coolant warning lamp comes on while the engine is running.
The coolant temperature has exceeded 248 ‡ (120 †). The airflow to the engine
radiator may be blocked or the coolant level may be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some fluids which
may have leaked into the engine compartment to catch fire.
Steam from the overheated engine can also cause serious burns which can occur
just by opening the hood.
There is a risk of injury.
XObserve the additional display messages in the multifunction display.
XPull over and stop the vehicle safely and switch off the engine, paying attention
to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 161).
XLeave the vehicle and keep a safe distance from the vehicle until the engine has
cooled down.
XCheck the coolant level and add coolant, observing the warning notes
(Ypage 328).
XIf you have to add coolant frequently, have the engine cooling system checked.
XMake sure that the air supply to the engine radiator is not blocked, e.g. by snow,
slush or ice.
Warning and indicator lamps in the instrument cluster289
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
XAt coolant temperatures below 248 ‡ (120 †), drive to the nearest qualified
specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in mountainous terrain
and stop-and-go traffic.
Driving systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
·NThe red distance warning lamp lights up while the vehicle is in motion. A warning
tone also sounds.
You are approaching a vehicle, a pedestrian or a stationary obstacle in your line of travel at too high a speed.
XBe prepared to brake immediately.
XPay careful attention to the traffic situation. You may have to brake or take
evasive action.
Further information on Distance Pilot DISTRONIC (
Ypage 176).
Further information on the distance warning function of Active Brake Assist
(
Ypage 67).
Further information on the distance warning function of Active Brake Assist with
cross-traffic function (
Ypage 72).
290Warning and indicator lamps in the instrument cluster
On-board computer and displays

Further information on engine oil (Ypage 389).
Additional service products
Important safety notes
GWARNING
Certain components in the engine compart-
ment, such as the engine, radiator and parts
of the exhaust system, can become very hot.
Working in the engine compartment poses a
risk of injury.
Where possible, let the engine cool down and touch only the components described in the
following.
GWARNING
The cooling system is pressurized, particularly
when the motor is warm. If you open the cap,
you could be scalded if hot coolant sprays out.
There is a risk of injury.
Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
The coolant level may only be checked and cool-
ant refilled when the engine and engine cooling
system have cooled down.
GWARNING
Windshield washer concentrate could ignite if it comes into contact with hot engine compo-
nents or the exhaust system. There is a risk of
fire and injury.
Make sure that no windshield washer con-
centrate is spilled next to the filler neck.
Checking coolant level
XPark the vehicle on a level surface.
Only check the coolant level when the vehicleis on a level surface and the engine has cooled
down.
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 140).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (
Ypage 142).
XCheck the coolant temperature gauge in the
multifunction display.
The coolant temperature must be below
158 ‡ (70 †).
XTurn the SmartKey to position in the ignition
lock u(Ypage 140).
XOn vehicles with KEYLESS-GO, press the
Start/Stop button (Ypage 142).
XPress the Start/Stop button (Ypage 142).
XSlowly turn cap :half a turn counter-clock-
wise and allow excess pressure to escape.
XTurn cap :further counter-clockwise and
remove it.
If the coolant is at the level of marker bar =
in the filler neck when cold, there is enough
coolant in coolant expansion tank ;.
If the coolant level is approximately 0.6 in
(1.5 cm) above marker bar =in the filler neck
when warm, there is enough coolant in expan-
sion tank ;.
XIf necessary, add coolant that has been tested
and approved by Mercedes-Benz.
XReplace cap :and turn it clockwise as far as
it will go.
For further information on coolant, see
(
Ypage 390).
328Engine compartment
Maintenance and care

!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:
Rtires
Rdoor gaps, roof gaps, joints, etc.
Relectrical components
Rbattery
Rplug-type couplings
Rlights
Rseals
Rtrim
Rventilation 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:
Rstickers
Rfilms
Rmagnetic 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.
XRemove dirt immediately, where possible,
while avoiding rubbing too hard.
XSoak insect remains with insect remover and
rinse off the treated areas afterwards.
XSoak bird droppings with water and rinse off
the treated areas afterwards.
XRemove coolant, brake fluid, tree resin, oils,
fuels and greases by rubbing gently with a
cloth soaked in petroleum ether or lighter
fluid.
XUse tar remover to remove tar stains.
XUse 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.
XUse 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:
RRubbing hard with unsuitable agents
RWashing 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.
332Care
Maintenance and care

Gasoline enginesMB-Freigabe orMB-Approval
All models229.5, 229.6
Mercedes‑AMG vehicles229.5
Diesel enginesMB-Freigabe orMB-Approval
GLS 350 d 4MATIC229.52
Mercedes-AMG vehicles: only use SAE 0W-40
or SAE 5W-40 engine oils.
iMB approval is indicated on the oil contain-
ers.
Filling capacities
The following values refer to an engine oil
change, including the oil filter.
ModelCapacity
GLS 350 d 4MATIC8.5 US qt (8.0 l)
GLS 550 4MATIC
Mercedes‑AMG
vehicles9.0 US qt (8.5l)
Allot her models7.4 US qt (7.0 l)
Additives
!Do not use any additives in the engine oil.
This could damage the engine.
Brake fluid
GWARNING
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
(
Ypage 386).
Only use brake fluid approved for Mercedes-
Benz according to MB-Freigabe or 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.
iHave 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
GWARNING
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.
Further information on coolants can be found
in the Mercedes-Benz Specifications for Ser-
vice Products, MB BeVo 310.1, e.g. on the
Internet at
http://bevo.mercedes-benz.com. Or con-
tact a qualified specialist 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.
iHave 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
(
Ypage 386).
390Service products and filling capacities
Technical data

The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It is responsible for
the following:
Ranti-corrosion protection
Rantifreeze protection
Rraising the boiling point
If the coolant has antifreeze protection down to -35 ‡ (-37 †), the boiling point of the coolant
during operation is approximately 266 ‡
(130 †).
The antifreeze concentrate/corrosion inhibitor
concentration in the engine cooling system
should:
Rbe at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 †).
Rnot exceed 55% (antifreeze protection down
to -49 ‡[-45 †]) .Otherwise ,hea twill no tbe
dissipated as effectively.
Mercedes-Ben zrecommends an antifreeze/
corrosion inhibitor concentrat ein accordance
wit hMB Specification sfo rServic eProducts
310.1.
iWhe nth evehicle is first delivered, it is filled
wit h a coolan tmixture that ensures adequat e
antifreez ean danti-corrosio nprotection .
iThe coolan tis checke dat specifie dintervals
at aqualifie dspecialis tworkshop .
Filling capacities
ModelCapacity
Mercedes ‑AMG
vehiclesApprox .11.9 US qt
(11. 3l)
GLS 350 d4MATICApprox .12.2 US qt
(11. 5l)
GLS 550 4MATICApprox .12.0 US qt
(11. 4l)
All other modelsApprox .10.3 US qt
(9.7 l)
Windshield washer syste m
Importan tsafet ynotes
GWARNING
Windshield washer concentrat ecould ignit eif
it come sinto contact wit hhot engin ecompo-
nent sor th eexhaus tsystem. There is aris kof
fir ean dinjury.
Mak esur ethat no windshield washer con-
centrat eis spilled next to th efiller neck .
!Only MB SummerFit an dMB WinterFit
washer fluid should be mixed together .The
spray nozzles may otherwise becom e
blocked.
Do no tuse distilled or de-ionized water .Other -
wise ,th elevel sensor may giv e afalse reading.
Whe nhandlin gwasher fluid, observe th eimpor -
tant safet ynote son servic eproducts
(
Ypage 386).
At temperature sabov efreezing:
XFill th ewasher fluid reservoir wit h amixture of
water an dwindshield washer fluid, e.g. MB
SummerFit .
Ad d 1 partMB SummerFit to 10 0parts water .
At temperature sbelow freezing:
XFill th ewasher fluid reservoir wit h amixture of
water an dwasher fluid, e.g. MB WinterFit .
Fo rth ecorrec tmixin gratio refe rto th einfor-
mation on th eantifreez ereservoir.
iAd dwindshield washer fluid, e.g. MB Sum -
merFit or MB WinterFit ,to th ewasher fluid all
year rou
nd.
Climat econtro lsyste m refrigerant
Important safety notes
The climate control system of your vehicle is fil-
led with refrigerant R ‑134a.
The instruction label regarding the refrigerant
type used can be found on the radiator cross
member.
!Only the refrigerant R ‑134a and the PAG oil
approved by Mercedes-Benz may be used.
The approved PAG oil may not be mixed with
any other PAG oil that is not approved for
Service products and filling capacities391
Technical data
Z