2018 MERCEDES-BENZ GLS SUV coolant level

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

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

from the data shown here. You can find the
data applicable to your vehicle on the vehicle
identification plate.
Vehicle identification number (VIN)
XOpen the front right-hand door.
XOpen cover:in the direction of the arrow
and remove it.
You will see the VIN.
The VIN can also be found in the following loca-
tions:
Ron the lower edge of the windshield
(Ypage 386)
Ron the vehicle identification plate
(Ypage 385)
Engine number
:Emission control information plate, includ-
ing the certification of both federal and Cali-
fornian emissions standards
;Engine number (stamped into the crank-
case)
=VIN (on the lower edge of the windshield)
Service products and filling capaci-
ties
Important safety notes
GWARNING
Service products may be poisonous and haz-
ardous to health. There is a risk of injury.
Comply with instructions on the use, storage
and disposal of service products on the labels
of the respective original containers. Always
store service products sealed in their original
containers. Always keep service products out
of the reach of children.
HEnvironmental note
Dispose of service products in an environ-
mentally responsible manner.
Service products include the following:
RFuels
RExhaust gas aftertreatment additives, e.g.
DEF
RLubricants (e.g. engine oil, transmission oil)
RCoolant
RBrake fluid
RWindshield washer fluid
RClimate control system refrigerant
Components and service products must match.
You should therefore only use products that
have been tested and approved by Mercedes-
Benz.
You can identify service products approved by
Mercedes-Benz by the following inscriptions on
the container:
RMB-Freigabe (e.g. MB-Freigabe 229.51)
RMB-Approval (e.g. MB-Approval 229.51)
Other designations or recommendations indi-
cate a level of quality or a specification in
accordance with an MB Sheet Number (e.g. MB 229.5). They have not necessarily been
approved by Mercedes-Benz.
Other identifications, for example:
R0 W-30
R5 W-30
R5 W-40
386Service 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