coolant level MERCEDES-BENZ GLS-Class SUV 2017 X166 Owner's Manual

CockpitOverview .......................................... 33
see Instrument cluster
Collapsible spare wheel
Inflating ........................................ .374
see Emergency spare wheel
COMAND
Driving dynamics display ............... 221
Switching on/off ........................... 288
COMAND display
Cleaning ......................................... 329
Combination switch .......................... 113
Connecting a USB device
see also Digital Operator's Man-
ual .................................................. 287
Consumption statistics (on-board
computer) .......................................... 232
Controller ........................................... 288
Convenience closing feature .............. 87
Convenience opening feature ............ 87
Coolant (engine)
Checking the level ......................... 322
Display message ............................ 257
Filling capacity ............................... 383
Important safety notes .................. 382
Temperature (on-board computer,
Mercedes-AMG vehicles) ............... 241
Temperature gauge ........................ 230
Warning lamp ................................. 283
Cooling
see Climate control
Copyright ............................................. 32
Cornering light function
Display message ............................ 256
Crash-responsive emergency light-
ing ....................................................... 117
Crosswind Assist ................................. 69
Crosswind driving assistance ............ 69
Cruise control
Activating ....................................... 173
Activation conditions ..................... 173
Cruise control lever ....................... 172
Deactivating ................................... 173
Display message ............................ 267
Driving system ............................... 172
Function/notes ............................. 172
Important safety notes .................. 172 Storing and maintaining current
speed ............................................. 173
Cup holder
Center console .............................. 303
Important safety notes .................. 302
Rear compartm ent ......................... 303
T

emperature controlled ................. 303
Third row of seats .......................... 304
Customer Assistance Center
(CAC) ..................................................... 29
Customer Relations Department ....... 29
D
Data
see Technical data
Data carrier
Selecting ........................................ 235
Daytime running lamps
Display message ............................ 256
Function/notes ............................. 112
Switching on/off (on-board com-
puter) ............................................. 239
Declarations of conformity ................. 28
DEF
Adding ........................................... 156
Display message ............................ 260
Filling capacity ............................... 381
Important safety notes .................. 381
Diagnostics connection ...................... 29
Differential lock (display mes-
sage) ................................................... 263
Digital speedometer ......................... 233
DIRECT SELECT lever
Automatic transmission ................. 146
Display messages
ASSYST PLUS ................................ 323
Calling up (on-board computer) ..... 244
Driving systems ............................. 261
Engine ............................................ 257
General notes ................................ 243
Hiding (on-board computer) ........... 243
KEYLESS-GO .................................. 273
Lights ............................................. 256
Safety systems .............................. 245
SmartKey ....................................... 273
Tires ............................................... 268
Vehicle ........................................... 270
8Index

ProblemPossible causes/consequences andMSolutions
Vehicles with a gasoline
engine:
The engine is not running
smoothly and is misfir-
ing.There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
XOnly depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it.
XHave the cause rectified immediately at a qualified specialist work-
shop.
The coolant temperature
gage shows a value
above 248 ‡ (120 †).The coolant level is too low. The coolant is too hot and the engine is no
longer being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant to
cool down.
XCheck the coolant level (Ypage 322). Observe the warning notes
as you do so and add coolant if necessary.
DYNAMIC SELECT controller
Use the DYNAMIC SELECT controller to change
the drive program. Depending on the drive pro-
gram selected the following vehicle character-
istics will change:
Rthe drive (engine and transmission manage-
ment)
Rthe transmission
Rthe suspension
Rthe steering
Rthe availability of the ECO start/stop function
Each time you start the engine with the Smart-
Key or the Start/Stop button, the Comfortdrive
program is activated. For further information
about starting the engine, see (
Ypage 139).
XAll vehicles (except Mercedes-AMG vehi-
cles): turn DYNAMIC SELECT controller :as many times as necessary until the desired
drive program is selected.
The selected drive program appears in the
multifunction display. After five seconds the
display goes out.
In addition, the current drive program settings
are displayed in the multimedia system dis-
play.
Drive programs available (all vehicles
except Mercedes-AMG vehicles):
IndividualIndividual settings
SportSporty driving characteris-
tics
ComfortComfortable and economi-
cal driving characteristics
SlipperyOptimal driving characteris-
tics on slippery or snow-
covered roads
Off-roadOptimal driving characteris-
tics for easily negotiable off-
road terrain
Offroad Plus
(vehicles with
Off-Road Engi-
neering pack-
age)Optimal driving characteris-
tics for rough terrain
DYNAMIC SELECT controller145
Driving and parking
Z

Towing a trailer
There are numerous legal requirements con-
cerning the towing of a trailer, e.g. speed restric-tions. Make sure that your car/trailer combina-
tion complies with the local regulations:
Rin your place of residence
Rin the location to which you are driving
The police and local authorities can provide reli- able information.
Observe the following when towing a trailer:
RTo gain driving experience and to become
accustomed to the new handling characteris-
tics, you should practice the following in a
traffic-free location:
-cornering
-stopping
-backing up
RBefore driving, check:
-trailer tow hitch
-safety switch for braked trailers
-safety chains
-electrical connections
-lights
-wheels
RAdjust the exterior mirrors to provide an
unobstructed view of the rear section of the
trailer.
RIf the trailer has electronically controlled
brakes, pull away carefully. Brake manually
using the brake controller and check whether
the brakes function correctly.
RSecure any objects on the trailer to prevent
the cargo from slipping when the vehicle is in
motion.
RWhen you couple up a trailer, check at regular
intervals that the load is firmly secured. If the
tra
iler is equipped with trailer lights and
brakes, check the trailer to ensure that these
are working.
RBear in mind that the handling will be less
stable when towing a trailer than when driving
without one. Avoid sudden steering move-
ments.
RThe vehicle/trailer combination is heavier,
accelerates more slowly, has a decreased
gradient climbing capability and a longer
braking distance.
It is more susceptible to side winds and
requires more careful steering.
RIf possible, do not brake suddenly, but instead depress the brake pedal moderately at first so
that the trailer can activate its brakes. Then
increase the pressure on the brake pedal.
RIf the automatic transmission repeatedly
shifts between gears on uphill or downhill gra-
dients, shift to a lower gear using the left-hand
steering wheel paddle shifter.
A lower gear and lower speed reduce the risk
of engine failure.
RWhen driving downhill, shift to a lower gear toutilize the engine's braking effect.
Avoid continuous brake application as this
may overheat the vehicle brakes and, if instal-
led, the trailer brakes.
RIf the coolant temperature increases dramat-
ically while the air-conditioning system is
switched on, switch off the air-conditioning
system.
Coolant heat can also be dissipated by open-
ing the windows and switching the ventilation blower and the interior temperature to the
highest level.
RWhen overtaking, pay particular attention to
the extended length of your vehicle/trailer
combination.
Due to the length of the vehicle/trailer com-
bination, you require additional road space in
relation to the vehicle you are overtaking
before you can change back to the original
lane.
Decoupling a trailer
GWARNING
If you uncouple a trailer with the overrun
brake engaged, you could trap your hand
between the vehicle and the trailer drawbar.
There is a risk of injury.
Do not uncouple a trailer if the overrun brake
is engaged.
GWARNING
Vehicles with level control:
The vehicle is lowered as soon as you discon-
nect the trailer cable. This could result in your
limbs or those of other people that are
between the vehicle body and tires or under-
226Towing a trailer
Driving an d parking

There is a short delay before a change in outside
temperature appears in the multifunction dis-
play.
Coolant temperature gauge
GWARNING
Opening the hood when the engine is over-
heated or when there is a fire in the engine
compartment could expose you to hot gases
or other service products. There is a risk of
injury.
Let an overheated engine cool down before
opening the hood. If there is a fire in the
engine compartment, keep the hood closed
and contact the fire department.
!A display message is shown if the coolant
temperature is too high.
If the coolant temperature is over 248 ‡
(120 †), do not continue driving. The engine
will otherwise be damaged.
The coolant temperature gage is in the instru-
ment cluster on the right-hand side (
Ypage 34).
Under normal operating conditions and with the
specified coolant level, the coolant temperature
may rise to 248 ‡ (120 †).
Operating the on-board computer
Overview
:Multifunction display
;Right control panel
=Left control panel
XTo activate the on-board computer: turn
the SmartKey to position 1in the ignition lock.
You can control the multifunction display and
the settings in the on-board computer using the
buttons on the multifunction steering wheel.
Vehicles with the COMAND multimedia system:
you can find further information on the Voice
Control System in the separate operating
instructions.
Vehicles with the Audio 20 multimedia system:
you can find further information on voice-oper-
ated navigation in the manufacturer's operating
instructions.
230Displays and operation
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
b
Switch On Headlamps
You are drivingwit 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:
Rth ewindshield in th ecamera' sfield of vision is dirty
Rvisibilit yis impaire ddue to heav yrain ,snow or fog
XClean th ewindshield.
If th esystem detects that th ecamera is full yoperational again ,th e
Adaptive
HighbeamAssistNowAvailablemessage 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 322).
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 messages257
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 159).
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 159).
XConsult aqualified specialist workshop .
258Display 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 156).
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 159).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster283
On-board computer and displays
Z

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 159).
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 322).
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 159).
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 322).
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.
284Warning and indicator lamps in the instrument cluster
On-board computer and displays

Where possible, let the engine cool down andtouch 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.
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 vehicle
is on a level surface and the engine has cooled
down.
XTurn the SmartKey to position 2in the ignition
lock (Ypage 138).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (
Ypage 140).
XCheck the coolant temperature gauge in the
multifunction display.
The coolant temperature must be below
158 ‡ (70 †).
XTurn the SmartKey to position 0in the ignition
lock (Ypage 138).
XOn vehicles with KEYLESS-GO, press the
Start/Stop button (Ypage 140).
XPress the Start/Stop button (Ypage 140).
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 382).
Adding washer fluid to the windshield
washer system
Example: washer fluid reservoir
XTo open: pull cap:upwards by the tab.
XAdd the premixed washer fluid.
XTo close: press cap :onto the filler neck
until it engages.
If the washer fluid level drops below the recom-
mended minimum of 1 liter, a message appears
in the multifunction display prompting you to
add washer fluid (
Ypage 273).
Further information on windshield washer fluid
(
Ypage 383).
322Engine 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 378)
Ron the vehicle identification plate
(Ypage 377)
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
378Service products and filling capacities
Technical data