2012 MERCEDES-BENZ G-Class check engine

Engine
Problem Possible causes/consequences and
M Solutions
! (USA only)
; (Canada only)
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 running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states/provinces, you are required by law to
immediately visit a qualified specialist workshop if the yellow
Check Engine

warning lamp lights up. If in doubt, check whether
such legal regulations apply in the state/province in which you
are currently driving. !
(USA only)
; (Canada only)
The yellow Check
Engine warning lamp
lights up while the
engine is running. 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
workshop. 9
The yellow reserve fuel
warning lamp lights up
while the engine is
running.
The fuel filler cap is not correctly closed.
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
workshop. 9
The yellow reserve fuel
warning lamp lights up
while the engine is
running.
The fuel level has dropped into the reserve range.
X
Refuel at the nearest gas station.184
Warning and indicator lamps in the instrument cluster
On-board computer and displays

X
Pull release lever : on the hood.
The hood is released.
! Make sure
that the windshield wipers are
not folded away from the windshield. You
could otherwise damage the windshield
wipers or the hood. X
Lift the hood slightly.
X Push hood catch handle ;
in
the direction
of the arrow and lift the hood.
Closing the hood G
WARNING
When closing the hood, use extreme caution
not to catch hands or fingers. Be careful that
you do not close the hood on anyone.
Make sure the hood is securely engaged
before driving off. Do not continue driving if
the hood can no longer engage after an
accident, for example. The hood could
otherwise come loose while the vehicle is in
motion and injure you and/or others. X
Lower the hood and let it fall from a height
of approximately 8 inches ( 20 cm).
X Check

that the hood has engaged properly.
If the hood can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force. Engine oil
Notes on the oil level Depending on the driving style, the vehicle
consumes up to 0.9 US qts
(0.8 l) of oil over
a distance of 600 miles (1,000 km). The oil
consumption may be higher than this when
the

vehicle is new or if you frequently drive at
high engine speeds.
Checking the oil level using the oil
dipstick On the G 55 AMG, the oil level can be checked
using the on-board computer.
When checking the oil level:
R
park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R the engine should be switched off for at
least 30 minutes if the engine is not at
operating temperature

(i.e. if you only start
the engine briefly). Oil dipstick (example: G 550) Engine compartment
211Maintenance and care Z

X
Pull oil dipstick : out of the dipstick guide
tube.
X Wipe off oil dipstick :.
X Slowly slide oil dipstick : into the guide
tube to the stop, and take it out again.
The oil

level is correct if the level is between
MIN mark = and MAX mark ;.
X Add oil if necessary.
Checking the oil level using the on-
board computer On the G 55 AMG, the oil level can be checked
using the on-board computer.
When checking the oil level:
R
park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
X Make sure that the SmartKey is in position
2 in the ignition lock.
X Press the & or * button on the
steering wheel to select the following
message: The measurement takes a few seconds. You
will
see

one of the following messages in the
multifunction display:
R Engine Oil Level OK
R Add 1.0 qt (Canada: 1.0 liter) to
reach maximum oil level. R
Add 1.5 qts (Canada: 1.5 liters) to
reach maximum oil level.
R Add 2.0 qts (Canada: 2.0 liters) to
reach maximum oil level.
X Add oil if necessary.
If the engine is at normal operating
temperature and the Engine Oil Reduce
Oil Level message appears, the engine oil
level is too high.
X Have excess oil siphoned off.
! Do not

add too much oil. Adding too much
oil can result in damage to the engine or the
catalytic converter. Have excess oil
siphoned off.
If the Switch ignition on to check
engine oil level message appears:
X Turn the SmartKey to position 2 in the
ignition lock.
If the Observe Waiting Time message
appears:
X If the engine is at normal operating
temperature: repeat the measurement
after about five minutes.
If the engine is not at normal operating
temperature (e.g. if the engine was only
started briefly): repeat the measurement
after about 30 minutes.
If the Engine Oil Level Not With
Engine On message appears:
X Switch off the engine.
X If the engine is at normal operating
temperature: wait about five minutes
before carrying out the measurement.
If the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly: wait about 30 minutes
before carrying out the measurement.
i If you wish to cancel the measurement,
press the * or & button on the
multifunction steering wheel. 212
Engine compartment
Maintenance and care

Adding engine oil
H
Environmental note
When adding oil, take care not to spill any. If
oil enters the soil or waterways, it is harmful
to the environment.
! Use only engine oils and oil filters that
have been approved for vehicles equipped
with a service system. A list of the engine
oils and oil filters tested and approved in
accordance with the Mercedes-Benz
Specifications for Service Products can be
obtained from any authorized Mercedes-
Benz Center.
Damage to
the engine or exhaust system is
caused by the following:
R using engine oils and oil filters which
have not been specifically approved for
the service system.
R replacing the engine oil or oil filter after
the replacement interval required by the
service system has elapsed
R using engine oil additives. Example: engine oil cap Engine oil cap (G 55 AMG)
X
Turn cap : counterclockwise
and remove
it.
X Add the amount of oil required.
Observe the specifications in the on-board
computer when

doing so or fill carefully to the
maximum mark on the oil dipstick.
i The difference in quantity between the
MIN mark and the MAX mark on the
dipstick is approximately 2.1 US qts. (2 l).
! Do not add too much oil. If the oil level is
above the "max" mark on the dipstick, too
much oil has been added. This can lead to
damage to the engine or the catalytic
converter. Have excess oil siphoned off.
For further information on engine oil, see
(Y page 275).
X Replace cap : on the filler neck and
tighten clockwise.
Ensure that the cap locks into place
securely. Checking and adding other service
products
Coolant level Only check the coolant level when the vehicle
is on

a level surface and the engine has cooled
down. Engine compartment
213
Maintenance and care Z

X
Turn the SmartKey to position
2(Y page 115) in the ignition lock.
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
158 ‡ (70 †). G
WARNING
In order to avoid any potentially serious burns:
R use extreme caution when opening the
hood if there are any signs of steam or
coolant leaking
from the cooling system, or
if the coolant temperature display indicates
that the coolant is overheated.
R do not remove the pressure cap on the
coolant reservoir if the coolant temperature
is above 158 ‡ (70 †). Allow the engine to
cool down before removing the cap. The
coolant reservoir contains hot fluid and is
under pressure.
R using a rag, slowly turn the cap
approximately 1
/ 2 turn to relieve excess
pressure. If opened immediately, scalding
hot fluid and steam will be blown out under
pressure.
R do not spill antifreeze on hot engine parts.
Antifreeze contains ethylene glycol which
may burn if it comes into contact with hot
engine parts. X
Slowly turn cap : half a turn
counterclockwise and allow excess
pressure to escape.
X Turn cap : further counterclockwise 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 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
tested 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 276).
Windshield washer system and
headlamp cleaning system The washer fluid reservoir is used for both the
windshield
washer

system and the headlamp
cleaning system. G
WARNING
Washer solvent/antifreeze is highly
flammable. Do not spill washer solvent/
antifreeze on

hot engine parts, because it may
ignite and burn. You could be seriously
burned.
! At temperatures below freezing: always
fill the washer fluid reservoir with a mix of
water and windshield washer concentrate
(e.g. MB WinterFit). There is otherwise a
risk of damaging the windshield washer
system/headlamp cleaning system.
! Only use washer fluid concentrate which
is suitable for plastic lenses. Unsuitable
washer fluid concentrate could damage the
plastic lenses of the headlamps. 214
Engine compartment
Maintenance and care

i
When refitting
cover panel ?, make sure
that retainer B engages in recess A.
Removing the spare wheel G
WARNING
Make sure no one is injured when removing
the spare wheel.
Grip wheel from the sides.
Keep hands from beneath the wheel. X
Remove wheel nuts :.
X Remove the spare wheel.
Mounting the wheel After changing a wheel:
X
Repair or replace the damaged wheel as
soon as possible and secure the spare
wheel in place again.
X Secure the damaged wheel on the spare
wheel bracket with wheel nuts :. When
doing so,

make sure that the wheel cannot
come loose. X
When refitting cover panel ?, make sure
that retainer B engages in recess
A(Y page 225).
X Make sure that tab ; is below when
refitting cover ring : (Y page 225).
X For safety reasons, regularly check to
ensure that

the wheel is securely fastened. Flat tire
Preparing the vehicle
X Stop the vehicle as far away as possible
from traffic

on solid, non-slippery and level
ground.
X Switch on the hazard warning lamps.
X Apply the parking brake.
X Bring the front wheels into the straight-
ahead position.
X Move the selector lever to P.
X Switch off the engine.
X Remove the SmartKey from the ignition
lock.
X All occupants must get out of the vehicle.
Make sure

that they are not endangered as
they do so.
X Make sure that no one is near the danger
area while a wheel is being changed.
Anyone who is not directly assisting in the
wheel change should, for example, stand
behind the barrier.
X Get out of the vehicle. Pay attention to
traffic conditions when doing so.
X Close the driver's door. Changing a wheel and mounting the
spare wheel
Important safety notes G
WARNING
If the spare tire is more than 6 years old or is
not the

same model as the regular tires, have226
Flat tire
Breakdown assistance

Position number
B identifies the charged battery of the other vehicle or an equivalent jump-
starting device.
X Lift up cover : of positive terminal = in the direction of the arrow.
X Connect positive terminal = on your vehicle to positive terminal ; of donor battery B
using the jumper cable, beginning with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal ? of donor battery B to earth point A of your vehicle using
the jumper cable, connecting the jumper cable to donor battery B first.
X Start the engine.
X First, remove the jumper cable from earth point A and negative terminal ?, then from
positive terminal
=

and positive terminal ;, each time disconnecting from the battery on
your own vehicle first.
X Have the battery checked at a qualified specialist workshop.234
Jump-starting
Breakdown assistance

You should have the brake fluid renewed at
regular intervals. The brake fluid change
intervals can be found in the Maintenance
Booklet.
Only use brake fluid approved by Mercedes-
Benz. Information about approved brake
fluids can be obtained from any authorized
Mercedes-Benz Center. Coolant
Important safety notes The coolant is a mixture of water and
antifreeze/corrosion inhibitor. It performs
the following tasks:
R
anti-corrosion protection
R antifreeze protection
R raising the boiling point
The engine cooling system is filled at the
factory with coolant which contains an
antifreeze/corrosion inhibitor that ensures
protection down to approximately -35 ‡
(-37 † ).
! Only add
coolant that has been premixed
with the desired antifreeze protection.
Otherwise, the engine could be damaged.
Further information on coolants and on
filling can be found in the Mercedes-Benz
Specifications for Service Products, MB
Approval 310.1, e.g. on the Internet at
http://bevo.mercedes-benz.com. You can
also consult an authorized Mercedes-Benz
Center.
! 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
the boiling point will be too low.
If the coolant has antifreeze protection down
to -35 ‡ (-37 † ), the boiling point of the
coolant in the pressurized system is
approximately 266 ‡ (130 † ). Your vehicle has a range of aluminum
components. Aluminum components in the
engine make it necessary to use
anticorrosion/antifreeze coolant which has
been specifically formulated to protect the
aluminum parts. Using other antifreeze/
corrosion inhibitors without these
characteristics affects the service life.
The
coolant

must be used throughout the year
in order to maintain the necessary corrosion
protection and provide protection from
overheating. In the Maintenance Booklet, you
can find information on the intervals for
renewal.
The renewal interval is determined by the
coolant type and the engine cooling system
design. The renewal interval in the
Maintenance Booklet is only valid if the
coolant is renewed or replenished with
Mercedes-Benz approved products.
Therefore, only use MB 326.0 antifreeze/
corrosion inhibitor or another Mercedes-Benz
approved product of the same specification.
Information on other products with the same
specifications that are approved by
Mercedes-Benz can be obtained at an
authorized Mercedes-Benz Center or on the
Internet at
http://bevo.mercedes-benz.com.
The coolant is checked at every maintenance
interval at an authorized Mercedes-Benz
Center.
The antifreeze/corrosion inhibitor
concentration in the engine cooling system
should:
R be at least 50%. This will protect the engine
cooling system against freezing down to
approximately -35 ‡ (-37 † ).
R not exceed 55% (antifreeze protection to
-49 ‡ [-45 † ]); otherwise, heat will not
dissipate as effectively.
If the coolant level is too low, MB 325.0
antifreeze/corrosion inhibitor should be
added. Have the engine cooling system
checked for possible leaks. 276
Service products and capacities
Technical data