2016 MERCEDES-BENZ G-Class coolant temperature

Engine
ProblemPossible causes/consequences andMSolutions
;
The yellow Check Engine
warning lamp lights up
while the engine is run-
ning.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.
XHave the vehicle checked as soon as possible at a qualified spe-
cialist workshop.
iIn 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 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.
XRefuel 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.
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.
?
The red coolant warning
lamp lights up while the
engine is running and the
coolant temperature
gage is at the start of the
scale.The temperature sensor for the coolant temperature gage is defective.
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, pay-
ing attention to road and traffic conditions. Do not continue driving
under any circumstances.
XApply the parking brake.
XConsult a qualified specialist workshop.
210Warning and indicator lamps in the instrument cluster
On-board computer and displays

ProblemPossible causes/consequences andMSolutions
?
The red coolant warning
lamp comes on while the
engine is running.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 malfunctioning.
The coolant is too hot and the engine is no longer being cooled suffi-
ciently.
XObserve the additional display messages in the multifunction dis-
play.
XPull over and stop the vehicle safely and switch off the engine, pay-ing attention to road and traffic conditions.
XApply the parking brake.
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 238).
XIf you need to add coolant more often than usual, have the engine
coolant 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 subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-start driving.
?
The red coolant warning
lamp comes on while the
engine is running. A
warning tone also
sounds.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 dis-
play.
XPull over and stop the vehicle safely and switch off the engine, pay- ing attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 130).
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 238).
Warning and indicator lamps in the instrument cluster211
On-board computer and displays
Z

ProblemPossible causes/consequences andMSolutions
XIf you need to add coolant more often than usual, have the engine
coolant system checked.
XMake sure that the air supply to the engine radiator is not blocked,
e.g. by snow, slush or ice.
XAt coolant temperatures below 248 ‡(120 †), drive to the nearest
qualified specialist workshop.
XAvoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-start driving.
Driving systems
ProblemPossible causes/consequences and MSolutions
·
The red distance warning
lamp lights up while the
vehicle is in motion.The distance to the vehicle in front is too small for the speed selected.
XIncrease the distance.
·
The red distance warning
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.
XBe prepared to brake immediately.
XPay careful attention to the traffic situation. You may have to brake
or take evasive action.
Further information on DISTRONIC PLUS (
Ypage 147).
212Warning and indicator lamps in the instrument cluster
On-board computer and displays

Let the engine cool down before you open the
cap. Wear gloves and eye protection. Slowly
open the cap to relieve pressure.
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 2(Ypage 112)
in the ignition lock.
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 294).
Adding washer fluid to the windshield
washer system/headlamp cleaning
system
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
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.
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.
On vehicles with the headlamp cleaning system,
the recommended minimum washer fluid level is
0.92 US gal (3.5 liters). On vehicles without the
headlamp cleaning system, the recommended
minimum washer fluid level is 0.26 US gal
(1 liter). If the washer fluid level drops below the
recommended minimum fluid level of
0.26 US gal (1 liter), a message appears in the
multifunction display prompting you to add
washer fluid (
Ypage 202).
Engine compartment239
Maintenance and care
Z

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 contact 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 Maintenance Booklet.
Comply with the important safety precautions
for service products when handling coolant
(
Ypage 289).
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the fol-
lowin g t
asks:
Rcorrosion protection
Rantifreeze protection
Rraising the boiling point
If the coolant has antifreeze protection down to -35 ‡(-37 †), the boiling point of the coolant in
the pressurized system is approximately 266 ‡ (130 †). The antifreeze/corrosion inhibitor concentra-
tion 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 in accordance wit hMB Spec -
ification 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 dcorrosion protection .
iThe coolantis checke dwit hever ymainte-
nanc einterval at aqualifie dspecialis twork-
shop.
The engin ecoolin gsyste mis filled wit hcoolan t
at th efactory whic hcontain santifreeze/corro-
sio ninhibitor that ensures protection down to
approximately -35 ‡(-37 †) .
Yo ur vehicle has a ran ge of alum
inum compo-
nents. Aluminum components in the engine
make itnecessary to use antifreeze/corrosion
inh ibit or that has been specific allyformulated to
protect the aluminum parts. Failure to use such
anticorrosion/antifreeze coolant willresult in a
significantly shortened service life.
The coolant must beused throughout the year in
order to maintain the necessary corrosion pro-
tection and to provide protection from over-
heating. Inthe Maintenance Booklet, you can
find information on the intervals for renewal.
The renewal interval is determined bythe cool-
ant type and the engine co oling system design.
The renewal interval in the Maintenance Booklet
is only valid if the coolant is renewed or added to
wit h Mercedes-Benz approved products. There-
fore, only use MB 326.0 antifreeze/corrosion
inh ibit or or another Mercedes-Benz approved
product of the same specification.
In formation on other products with the same
specifications that are approved byMercedes-
Benz can beobtained at an authorized
Mercedes-Benz Center or on the Internet at
ht tp://bevo.mercedes-benz.com .
If the coolant level is too low, MB 325.0 anti-
freeze/corrosion inh ibitor should beadded.
Have the engine co oling system c
hecked for
possible leaks.
294Service products and filling capacities
Technical data