2018 MERCEDES-BENZ GLS SUV engine coolant

Display messagesPossible causes/consequences andMSolutions
b
Switch Off Lights
You leaveth evehicl eand th elights are switched on . Awarning tone
also sounds.
XTurn th eligh tswitch to th eà position .
b
Switch On Headlamps
You are drivin gwit hlow-beam headlamp sswitched off .
XTurn theligh tswitch to th eL orà position .
Adaptive HighbeamAssist CurrentlyUnavailable SeeOperator' sManual
Adaptive Highbea mAssis tis deactivated and temporarily inoperative.
Possibl ecauses are:
RThe windshield in th ecamera' sfield of vision is dirty.
RVisibilit yis impaire ddue to heav yrain ,snow or fog .
XClean thewindshield.
If th esystem detects that th ecamera is full yoperational, th eAdap‐
tiv eHighbeam Assist Now Availablemessage is displayed.
Adaptive Highbea mAssis tis operational again .
Adaptive HighbeamAssist InoperativeAdaptive HighbeamAssis tis faulty.
XVisit aqualified specialist workshop .
Engine
Display messagesPossible causes/consequences and MSolutions
+
CheckCoolantLevelSee Operator' sMan ‐ual
The coolan tlevel is to olow.
!Avoid making lon gjourneys wit hto olittl ecoolan tin th eengin e
coolin gsystem. The engin ewill otherwise be damaged.
XAd dcoolant, observing th ewarning note sbefore doin gso
(Ypage 328).
If you have to ad dcoolant frequently:
XContac t aqualified specialist workshop and hav eth eengin ecoolin g
system checked.
?The fan motor is malfunctioning .
XAt coolanttemperatures belo w24 8‡( 120 †), drive to the nearest
qualified specialist workshop.
XAvoid heavy loads on the engine as you do so, e.g. driving in moun-
tainous terrain and stop-and-go traffic.
Display messages261
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
?
CoolantToo HotSto pVehicl eTur nEngine Off
The coolan tis to ohot .
A warning tone also sounds.
GWARNIN G
Do no tdrive when your engin eis overheated. This can caus esom e
fluids whic hmay hav eleaked int oth eengin ecompartmen tto catch
fire.
Steam from th eoverheate dengin ecan also caus eserious burn swhic h
can occur jus tby opening th ehood.
There is aris kof injury.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XWait until th eengin ehas cooled down .
XMakesur ethat th eair supply to th eengin eradiato ris no tblocked,
e.g. by snow, slus hor ice .
XDo no tstart th eengin eagain until th edisplay message goe sout and
th ecoolan ttemperature is belo w24 8 ‡ (120†). Otherwise ,th e
engin ecould be damaged.
XPay attention to th ecoolan ttemperature gauge .
If th etemperatur eincreases again:
XVisit aqualified specialist workshop immediately.
Under normal operating condition sand wit hth especified coolan t
level, th ecoolan ttemperature may ris eto 24 8 ‡(120†).
#
See Operator' sMan ‐ual
The battery is no tbein gcharged.
A warning tone also sounds.
Possibl ecauses are:
Radefective alternato r
Ratorn poly-V-belt
Ramalfunction in th eelectronics
!Do no tcontinu edriving. The engin ecould otherwise overheat.
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 161).
XConsult aqualified specialist workshop .
262Display messages
On-board computer and displays

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

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

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