coolant level MERCEDES-BENZ G-CLASS 2018 Owner's Manual

Problem with the rear window
defroster ........................................101
Problems with "cooling with air
dehumidification" .............................9 8
Refrigerant .................................... .287
Refrigerant filling capacity ............. 288
Setting the air distribution ...............9 9
Setting the air vents ...................... 102
Setting the airflow ........................... 99
Setting the temperature .................. 99
Switching air-recirculation mode
on/off ............................................ 102
Switching on/off .............................. 98
Switching residual heat on/off ...... 102
Switching the rear window
defroster on/off ............................ 101
Switching the ZONE function
on/off ............................................ 100
Windshield defroster ...................... 101
Clock (on-board computer) ............... 169
Cockpit
Overview .......................................... 31
COMAND
see separate operating instructions
COMAND display
Cleaning ......................................... 241
Combination switch ............................ 88
Connecting a USB device
see also Digital Operator's Man-
ual .................................................. 203
Consumption statistics (on-board
computer) .......................................... 163
Controller ........................................... 204
Controlling speed
see DISTRONIC PLUS
Convenience closing feature .............. 70
Convenience opening feature ............ 70
Coolant (engine)
Checking the level ......................... 234
Display message ............................ 180
Filling capacity ............................... 287
Notes ............................................. 286
Temperature (on-board com-
puter) ............................................. 171
Temperature gauge ........................ 161
Warning lamp ................................. 199 Cooling
see Climate control
Copyright ............................................. 29
Cruise control
Cruise control lever ....................... 133
Deactivating ................................... 134
Driving system ............................... 133
Functio
n/notes ............................. 133
General notes ................................ 133
Important safety notes .................. 133
Resuming the stored speed ........... 134
Setting a speed .............................. 134
Storing and maintaining current
speed ............................................. 133
Cup holder
Center console .............................. 215
Important safety notes .................. 215
Rear compartment ......................... 215
D
Datasee Technical data
Date (on-board computer) ................ 168
Daytime running lamps
Display message ............................ 180
Switching on/off (on-board com-
puter) ............................................. 169
Switching on/off (switch) ................ 86
Delayed switch-off
Exterior lighting (on-board com-
puter) ............................................. 169
Interior lighting .............................. 169
Diagnostics connection ...................... 27
Differential locks
Disengaging ................................... 153
Engaging ........................................ 151
Front axle ...................................... 152
General notes ................................ 151
Rear axle ........................................ 152
Terrain ........................................... 151
Transfer case ................................. 152
Digital Operator's Manual
Help ................................................. 22
Introduction ..................................... 22
Digital speedometer ......................... 163
Display messages
Calling up (on-board computer) ..... 174
Index7

Switching air-recirculation mode
on/off
General notes
If you switch on air-recirculation mode, the win-
dows can fog up more quickly, in particular at
low temperatures. Only use air-recirculation
mode briefly to prevent the windows from fog-
ging up.
Activating/deactivating
XTurn the SmartKey to position 2in the igni-
tion lock (Ypage 105).
XTo activate: press thedbutton.
The indicator lamp in the dbutton lights
up.
iAir-recirculation mode is automatically acti-
vated at high levels of pollution or at high out-
side temperatures. When air-recirculation
mode is activated automatically, the indicator
lamp in the dbutton is not lit.
Outside air is added after about 30 minutes.
XTo deactivate: press thedbutton.
The indicator lamp in the dbutton goes
out.
iAir-recirculation mode switches off auto-
matically:
Rafter approximately five minutes at outside
temperatures below approximately 41 ‡
Rafter approximately five minutes if cooling
with air dehumidification is deactivated
Rafter approximately 30 minutes at outside
temperatures above approximately 41 ‡
(5 †)
Switching the residual heat on or off
General notes
The residual heat function is only available on
vehicles for Canada.
It is possible to make use of the residual heat of
the engine to continue heating the stationary
vehicle for up to 30 minutes after the engine has
been switched off. The heating time depends on the set interior temperature.
Activating/deactivating
XTurn the SmartKey to position gin the igni-
tion lock (Ypage 105) or remove it.
XTo activate: press theÁbutton.
The indicator lamp in the Ábutton lights
up.
iThe blower will run at a low speed regardless
of the airflow setting.
iIf you activate the residual heat function at
high temperatures, only the ventilation will be
activated.
XTo deactivate: press theÁbutton.
The indicator lamp in the Ábutton goes
out.
Residual heat is deactivated automatically:
Rafter approximately 30 minutes
Rwhen the ignition is switched on
Rif the battery voltage drops
Rif the coolant temperature is too low
Air vents
Important safety notes
GWARNING
Very hot or very cold air can flow from the air
vents. This could result in burns or frostbite in
the immediate vicinity of the air vents. There
is a risk of injury.
Make sure that all vehicle occupants always
maintain a sufficient distance to the air out-
lets. If necessary, redirect the airflow to
another area of the vehicle interior.
In order to ensure the direct flow of fresh air
through the air vents into the vehicle interior,
please observe the following notes:
Rkeep the air inlet between the windshield and
the hood free of blockages, such as ice, snow or leaves.
Rnever cover the air vents or air intake grilles in
the vehicle interior.
iFor virtually draft-free ventilation, adjust the
sliders of the air vents to the center position.
iIf the automatic climate control constantly
differs from the set temperature or if unde-
102Air vents
Climate control

ProblemPossible causes/consequences andMSolutions
The coolant temperature
gauge is in the area
marked in red behind the
H. A display message
may also appear in the
multifunction display
and a warning tone may
sound.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 234). Observe the warning notes
as you do so and add coolant if necessary.
If the coolant level is correct, the radiator fan may be faulty. The cool-
ant is too hot and the engine is no longer being cooled sufficiently.
XIf the coolant temperature is below the Hmarking, 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.
Adjustable damping
General notes
With adjustable damping you can choose
between two different suspension settings.
Suspension settings
COMFcomfortable suspension setting
Sportsports suspension setting
Selecting the suspension setting
iIf you select the sports suspension setting,
the vehicle will dampen more roughly.
XPress button :.
The indicator lamp lights up. SPORTis dis-
played in the multifunction display. The sports
suspension setting is activated.
iIf you select the comfortable suspension
setting, the vehicle will dampen more softly.
XPress button ;.
The indicator lamp lights up. COMFis dis-
played in the multifunction display. The com-
fortable suspension setting is activated.
Automatic transmission
Important safety notes
GWARNING
If the engine speed is above the idling speed
and you engage transmission position Dor R,
the vehicle could pull away suddenly. There is
a risk of an accident.
When engaging transmission position Dor R,
always firmly depress the brake pedal and do not simultaneously accelerate.
GWARNING
The automatic transmission switches to neu-
tral position Nwhen you switch off the engine.
The vehicle may roll away. There is a risk of an
accident.
After switching off the engine, always switch
to parking position P. Prevent the parked vehi-
cle from rolling away by applying the parking
brake.
iBear in mind that the power transmission
between the engine and the transmission is
interrupted when the engine is switched off.
Automatic transmission111
Driving and parking
Z

Towing a trailer
There are several legal requirements for towing
a trailer, e.g. the maximum permissible speed.
Make sure that your car/trailer combination
complies with the local regulations:
Rin your place of residence
Rat your destination
The police and local authorities can provide reli- able information.
In order to accumulate driving experience and
accustom yourself to the new handling charac-
teristics, practice the following at a location
where there is no traffic:
RCornering
RStopping
RBacking up
Before driving, check the following:
RTrailer tow hitch
RSafety switch for braked trailers
RSafety chains
RElectrical connections
RLighting system
RWheels and tires
RLoad-securing measures
Adjust the exterior mirrors to provide an unob-
structed view of the rear section of the trailer.
Trailers with electronically controlled
brakes: pull away carefully in the vehicle/trailer
combination, brake manually using the brake
controller and check whether the brakes func-
tion correctly.
Check the load securing measures on a regular
basis.
When towing a trailer, your vehicle's handling
characteristics will be different in comparison
with when driving without a tra
iler.
The vehicle/trailer combination:
Ris heavier
Ris restricted in its acceleration and gradient-
climbing capability
Rhas an increased braking distance
Ris affected more by strong crosswinds
Rdemands more sensitive steering
Rhas a larger turning radius
Avoid sudden steering movements.
Avoid braking abruptly. If possible, brake gently
at first to allow the trailer to run on. Then,
increase the braking force rapidly. When overtaking, pay particular attention to the
extended length of your vehicle/trailer combi-
nation.
Due to the length of the vehicle/trailer combi-
nation, you require additional road space when
overtaking before you can change back to the
original lane.
If the automatic transmission repeatedly shifts
between gears on uphill or downhill gradients,
shift to a lower gear.
Driving in a lower gear and at a reduced speed
decreases the risk of engine damage.
Avoid constant braking. Otherwise, the vehicle
brakes and possibly also the trailer brakes may
overheat.
When driving downhill, shift to a lower gear to
utilize the engine's braking effect.
If the coolant temperature increases dramati-
cally while the air-conditioni ng s
ystem is
switched on, switch off the air-conditioning sys- tem.
Coolant heat can also be dissipated by opening
the windows and switching the ventilation
blower and the interior temperature to the high-
est level.
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.
!Do not disconnect a trailer with an engaged
overrun brake. Otherwise, your vehicle could
be damaged by the rebounding of the overrun
brake.
XApply the parking brake.
XMake sure that the automatic transmission is
set to position P.
XSecure the vehicle and trailer against rolling
away.
XClose all doors, including the rear door.
XRemove the trailer cable.
XRemove the safety chains, if there are any.
XUncouple the trailer.
158Towing a trailer
Driving an d parking

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.
!If the coolant temperature is too high, a dis-
play message is shown.
If the coolant temperature display is in the
area marked in red, do not continue driving.
Otherwise, the engine will be damaged.
The coolant temperature gage is in the instru-
ment cluster on the right-hand side (
Ypage 32).
Under normal operating conditions and at the
correct coolant level, the gauge may rise to the
H marking.
Operating the on-board computer
Overview
:Multifunction display
;Switches on the Voice Control System (see
the separate operating instructions)
=Right control panel
?Left control panel
ABack button
XTo activate the on-board computer: turn
the SmartKey to position 1in the ignition
lock (
Ypage 105).
You can control the multifunction display and
the settings in the on-board computer using the
buttons on the multifunction steering wheel.
Left control panel
=
;RCalls up the menu and menu bar
9
:Press briefly:
RScrolls in lists
RSelects a submenu or function
RIn the Audiomenu: selects the
previous or next station, when the
preset list or station list is active,
or an audio track or video scene
RIn the Tel(telephone) menu:
switches to the phone book and
selects a name or telephone num-
ber
9
:Press and hold:
RIn the Audiomenu: selects a pre-
set list or a station list in the
desired frequency range or an
audio track or video scene using
rapid scrolling
RIn the Tel(Telephone) menu:
starts rapid scrolling if the phone
book is open
aRConfirms a selection/display mes-
sage
RIn the Tel(Telephone) menu:
switches to the phone book and
starts dialing the selected number
Right control panel
~RRejects or ends a call
RExits phone book/redial memory
6RMakes or accepts a call
RSwitches to the redial memory
W
XRAdjusts the volume
Displays and operation161
On-board computer and displays
Z

Lights
Display messagesPossible causes/consequences andMSolutions
b
Example:Check LeftLow Beam
The bulb in question is malfunctioning.
XVisit a qualified specialist workshop.
or
XCheck whether you are permitted to replace the bulb yourself
(Ypage 89).
iLED light sources: the display message for the corresponding
lamp only appears when all the LEDs in the lamp have failed.
b
Malfunction SeeOperator's Manual
The exterior lighting is malfunctioning.
XVisit a qualified specialist workshop.
b
Auto Lamp FunctionInoperative
The light sensor is defective.
XVisit a qualified specialist workshop.
b
Switch Off Lights
The lights are still switched on when you leave the vehicle. A warning
tone also sounds.
XTurn the light switch to position Ã.
Engine
Display messagesPossible causes/consequences and MSolutions
+
CheckCoolantLevelSee Operator's Man‐ual
The coolant level is too low.
XAdd coolant, observing the warning notes before doing so
(Ypage 234).
XHave the coolant system checked at a qualified specialist workshop
if the coolant needs topping up more often than usual.
?The fan motor is malfunctioning.
XIf the coolant temperature is below the Hmark, 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-start traffic.
180Display messages
On-board computer and displays

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 122).
XLeaveth evehicl eand keep asaf edistanc efrom th evehicl euntil th e
engin 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 wtheH marking .Otherwise ,th e
engin ecould be damaged.
XPay attention to th ecoolan ttemperature gauge .
XIf thetemperature increases again ,visit aqualified specialist work-
sho pimmediately.
Under normal operating condition sand at th ecorrec tcoolan tlevel,
th egauge may ris eto th eH marking .
The poly-V-belt may hav etorn .
XPull ove rand stop th evehicl esafely and switch off th eengine, pay-
ing attention to roa dand traffic conditions.
XChec kth epoly-V-belt .
If th epoly-V-belt is torn:
!Do no tcontinu edriving. The engin ecould otherwise overheat.
XConsult aqualified specialist workshop .
If th epoly-V-belt is not damaged :
XWait until thedisplay message disappear sbefore restarting th e
engine. Otherwise ,th eengin ecould be damaged.
XPay attention to th ecoolan ttemperature gauge .
XVisitaqualified specialist workshop .
Display messages181
On-board computer and displays
Z

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
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.
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 122).
XConsult a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster199
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 122).
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 234).
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 gauge is below the H
marking (Ypage 161). 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 gauge has exceeded the Hmarking (
Ypage 161). 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 122).
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 234).
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.
200Warning and indicator lamps in the instrument cluster
On-board computer and displays

If you need to do any work inside the engine
compartment:
Rswitch off the ignition
Rnever reach into the area where there is a
risk of danger from moving components,
such as the fan rotation area
Rremove jewelry and watches
Rkeep items of clothing and hair, for exam-
ple, away from moving parts
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
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.
Checking coolant level
Checking the coolant level (example)
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 igni-
tion lock (Ypage 105).
XCheck the coolant temperature display in the
instrument cluster.
The coolant temperature must be below
158 ‡ (70 †).
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 cool-
ant expansion 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 286).
Adding washer fluid to the windshield
washer system/headlamp cleaning
system
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.
234Engine compartment
Maintenance and care