2015 MERCEDES-BENZ G-Class coolant temperature

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
(Y page 197).
Under normal operating conditions and with
the specified coolant level, the coolant tem-
perature may rise to 248 ‡ (120 †). Tachometer
! Do not drive in the overrevving range, as
this could damage the engine.
The red band in the tachometer indicates the engine's overrevving range.
The fuel supply is interrupted to protect the
engine when the red band is reached. Outside temperature display
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Bear in mind that the outside temperature
display indicates the temperature measured
and does not record the road temperature.
The outside temperature display is in the mul- tifunction display (Y page 199).
Changes in the outside temperature are dis-
played after a short delay. Speedometer with segments
The segments in the speedometer indicate
which speed range is available.
R Cruise control activated (Y page 162):
The segments light up from the stored
speed to the maximum speed.
R Variable SPEEDTRONIC activated
(Y page 166):
The segments light up from the start of the
scale to the selected limit speed.
R DISTRONIC PLUS activated (Y page 171):One or two segments in the set speed
range light up.
R DISTRONIC PLUS detects a vehicle in front:
The segments between the speed of the
vehicle in front and the stored speed light
up. 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
A Back button
X To activate the on-board computer: turn
the SmartKey to position 1(Y page 133) in
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. 198
Displays and operationOn-board computer and displays

Further information on the EASY-ENTRY/EXIT
feature (Y page 92).
Switching the fold-in mirrors when lock-
ing feature on/off
When you activate the Auto.
Auto. Mirror Mirror Fold‐
Fold‐
ing
ing function, the exterior mirrors are folded
in when the vehicle is locked. If you unlock the vehicle and then open a door, the exterior
mirrors fold out again.
X Press the =or; button on the steer-
ing wheel to select the Sett.
Sett. menu.
X Press the :or9 button to select the
Convenience
Convenience submenu.
X Press ato confirm.
X Press :or9 to select the Auto. Auto.
Mirror Folding
Mirror Folding function.
If the Auto. Mirror Folding
Auto. Mirror Folding function is
activated, the vehicle's exterior mirror is
displayed in red in the multifunction dis-
play.
X Press the abutton to save the setting. :
To fold the exterior mirrors in or out
If you have switched the Auto. Mirror
Auto. Mirror
Folding
Folding on and you fold the exterior mirrors
in using button :, they will not fold out auto-
matically (Y page 93).
You can then only fold out the exterior mirrors
using button :. Restoring the factory settings
X Press the =or; button on the steer-
ing wheel to select the Sett. Sett.menu.
X Press the :or9 button to select the
Factory Setting Factory Setting submenu.
X Press ato confirm.
The Reset All Settings?
Reset All Settings? message
appears.
X Press the :or9 button to select No
No
or Yes
Yes.
X Press ato confirm the selection.
If you select Yes Yes, the multifunction display
shows a confirmation message.
For safety reasons, the Daytime Running Daytime Running
Lights
Lights function in the Lights
Lightssubmenu is
only reset if the vehicle is stationary. AMG menu in AMG vehicles
AMG displays :
Digital speedometer
; Gear indicator
= Upshift indicator
? Engine oil temperature
A Coolant temperature
B Status indicator for ECO start/stop func-
tion (Y page 135)
X Press =or; on the steering wheel
to select the AMG
AMGmenu.
Upshift indicator UP
UP= indicates that the
engine has reached the overrevving range
when in the manual gearshift program.
Upshift indicator UP UP= fades out other mes-
sages until you have shifted up.
If the engine oil temperature is below 176 ‡
(80 †), the oil temperature is shown in blue. Menus and submenus
209On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions b
Check Check
Left
LeftDaytime
Daytime
Running
Running
Lamp Lampor Check Right
Check Right
Daytime Running
Daytime Running
Lamp Lamp The left or right-hand daytime running lamp is defective.
X Visit a qualified specialist workshop. b
Malfunction. See Malfunction. See
Operator's Manual Operator's Manual The exterior lighting is defective.
X Visit a qualified specialist workshop. b
Auto Auto
Lamp
LampFunction
Function
Inoperative
Inoperative The light sensor is defective.
X Visit a qualified specialist workshop. b
Switch Off Lights Switch Off Lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Turn the light switch to Ã.Engine
Display messages
Possible causes/consequences and
M MSolutions +
Check Coolant Check Coolant
Level. See Opera‐ Level. See Opera‐
tor's Manual tor's Manual The coolant level is too low.
X Add coolant, observing the warning notes before doing so
(Y page 278).
X Have the coolant system checked at a qualified specialist work-
shop if the coolant needs topping up more often than usual. ? The fan motor is faulty.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. Display
messages
221On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions ?
Coolant Too Hot Coolant Too Hot
Stop Vehicle Stop Vehicle
Switch Engine Off Switch Engine Off The coolant is too hot.
A warning tone also sounds.
G WARNING
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.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 150).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †). Other-
wise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †). The poly-V-belt may have torn.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Check the poly-V-belt.
If the poly-V-belt is torn:
! Do not continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is not damaged:
X Wait until the display message disappears before restarting the
engine. Otherwise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X Visit a qualified specialist workshop. 222
Display
messagesOn-board computer and displays

Engine
Problem
Possible causes/consequences and
M
MSolutions ;
The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, for example:
R in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system
R in the fuel system
The emission limit values may be exceeded and the engine may be
in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you must immediately visit a qualified special-
ist workshop as soon as the yellow Check Engine warning lamp
lights up. This is due to the legal requirements in effect in these
states. If in doubt, check whether such legal regulations apply in the state in which you are currently driving. 8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
X Refuel at the nearest gas station. 8
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 system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
X Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed: close the fuel filler
cap.
X If the fuel filler cap is closed: visit a qualified specialist work-
shop. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gage is at the
start of the scale. The temperature sensor for the coolant temperature gage is defec-
tive.
The coolant temperature is no longer being monitored. There is a risk of engine damage if the coolant temperature is too high.
X Pull 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.
X Apply the parking brake.
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
243On-board computer and displays Z

Problem
Possible causes/consequences and
M
MSolutions ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
! Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
If the coolant level is correct, the airflow to the engine radiator may be blocked or the electric engine radiator fan may be malfunc-
tioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Apply the parking brake.
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes (Y page 278).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the coolant temperature is
below 248 ‡(120 †). Otherwise, the engine could be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-start driving. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds. The coolant temperature has exceeded 248 ‡ (120 †). The air-
flow to the engine radiator may be blocked or the coolant level may
be too low.
G WARNING
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. 244
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem
Possible causes/consequences and
M
MSolutions X
Observe the additional display messages in the multifunction
display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 150).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes (Y page 278).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X At coolant temperatures below 248 ‡ (120 †), drive to the
nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-start driving. Driving systems
Problem
Possible causes/consequences and
M MSolutions ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. The distance to the vehicle in front is too small for the speed
selected.
X Increase the distance. ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion. A warning tone also
sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
Further information on DISTRONIC PLUS (Y page 169).Warning and indicator lamps in the instrument cluster
245On-board computer and displays Z

Additional service products
Checking coolant level G
WARNING
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. G
WARNING
The engine cooling system is pressurized, par- ticularly when the engine is warm. When
opening the cap, you could be scalded by hotcoolant spraying out. There is a risk of injury.
Let the engine cool down before opening the
cap. Wear eye and hand protection when
opening the cap. Open the cap slowly half a
turn to allow pressure to escape. X
Park the vehicle on a level surface.
Only check the coolant level when the vehi-
cle is on a level surface and the engine has
cooled down.
X Turn the SmartKey to position
2(Y page 133) in the ignition lock.
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †). X
Slowly turn cap :half a turn counter-
clockwise to allow excess pressure to
escape.
X Turn 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 coolant expansion tank ;.
X If necessary, add coolant that has been tes-
ted and approved by Mercedes-Benz.
X Replace cap :and turn it clockwise as far
as it will go.
For further information on coolant, see
(Y page 342).
Adding washer fluid to the windshield
washer system/headlamp cleaning
system G
WARNING
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. G
WARNING
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. 278
Engine compartmentMaintenance and care