check engine MERCEDES-BENZ G-CLASS SUV 2012 Service Manual

The ASSYST service interval display does not
take into account any periods of time during
which the battery is disconnected.
Hiding aservice message X
To hide the service message, press the
% back button on the multifunction
steering wheel ( Ypage 31)( Ypage 214).
Displaying service messages Use the buttons on the multifunction steering
wheel.
X Switch the ignitio non.
X Press VorU to select the standard
display menu on the steering wheel
(Y page 215).
X Press &or* to select the ASSYST
service interval display.
The ¯ or± service symbol and the
service due date are displayed.
Information about Service Arduous operating conditions or increased
loads on the vehicle will require some service
work to be performed more often than for a
vehicle in normal use. Such arduous condi-
tions include regular city driving with frequent
intermediate stops and use in mountainous
terrai noronp oor road surfaces.
For example, if the vehicle is used under ardu-
ous operating conditions, have air filters,
engine oil and oil filters changed frequently
and check the wheels often.F urther informa-
tion can be obtained at a qualified specialist
workshop, e.g. a Mercedes-Ben zService
Centre. Fuel/water separator
H
Environmental note
Dispose of service products in an environ-
mentally-responsible manner. !
If you continue driving without having the
fuel/water separator serviced, this could
cause damage to the engine. Any resulting
damage is not covered by the warranty.
If the fuel/water separator needs servicing,
the following message appears in the multi-
function display: You will also hear a brief warning tone.
X
Visit a qualified specialist workshop as
soon as possible. Care
General notes
Regular care of your vehicle is a condition for
retaining the quality in the long term.
Use care products and cleaning agents rec-
ommended and approved by Mercedes-Benz.
! For cleaning your vehicle, do not use any
of the following:
R dry, rough or hard cloths
R abrasive cleaning agents
R solvents
R cleaning agents containing solvents
Do not scrub.
Do not touch the surfaces or protective
films with hard objects, e.g. a ring or ice
scraper. You could otherwise scratch or
damage the surfaces and protective film. H
Environmental note
Dispose of empty packaging and cleaning
cloths in an environmentally responsible man-
ner.
! Do not park up the vehicle for an extended
period straight after cleaning it, particularly Care
295Maintenance and care Z

X
Vehicles with stainless-steel spare
wheel cover: make sure when refitting
cove rpanel ?that retainer Aengages in
recess B(Ypage 308).
X Make sure that tab ;is below when refit-
ting cover ring :(Ypage 308).
X For safety reasons, regularly check to
ensure that the wheel is securely fastened. G-Class Cabriolet
i
Secure the spare wheel of the G-Class
Cabriolet on spare wheel bracket ;, so
that valve :is accessible for checking the
tyre pressure. Flat tyre
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
(Y page 109).
X Deactivate the automatic door locking
(Y page 223).
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 key from the ignition lock.
The steering wheel lock stays active for as
long as the key is removed. 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. Any-
one 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 traf-
fic conditions when doing so.
X Close the driver's door.
X Place the warning triangle (Y page 304) or
warning lamps at a suitable distance.
Observe legal requirements. Battery (vehicle)
Important safety notes
Work on the battery, e.g. removing or instal-
ling, requires specialist knowledge and the
use of special tools. Therefore, always have
work on the battery carried out at a qualified
specialist workshop. G
WARNING
Work carried out incorrectly on the battery
can, for example, lead to a short circuit and
damage your vehicle's electronic system. This
can disrupt driving safety systems such as
ABS (anti-lock braking system) or ESP ®
(Elec-
tronic Stability Program).
R If ABS malfunctions, the wheels can lock
during braking. This limits the steerability
of the vehicle when braking and the braking
distance may increase. There is a risk of
accident.
R If ESP ®
malfunctions, the vehicle will not be
stabilised if it starts to skid or a wheel starts
to spin. There is a risk of accident.
You should therefore have all work involving
the battery carried out at a qualified specialist
workshop. Battery (vehicle)
309Breakdown assistance Z

G
WARNING
During the charging process, a battery produ-
ces hydrogen gas. If a short circuit occurs or
sparks are created, the hydrogen gas can
ignite. There is a risk of an explosion.
R Make sure that the positive terminal of a
connected battery does not come into con-
tact with vehicle parts.
R Never place metal objects or tools on a bat-
tery.
R It is important that you observe the descri-
bed order of the battery terminals when
connecting and disconnecting a battery.
R When jump-starting, make sure that the
battery poles with identical polarity are
connected.
R It is particularly important to observe the
described order when connecting and dis-
connecting the jump leads.
R Never connect or disconnect the battery
terminals while the engine is running. G
WARNING
Electrostatic build-up can lead to the creation
of sparks, which could ignite the highly explo-
sive gases of a battery .There is a risk of an
explosion.
Before handling the battery, touch the vehicle
body to remove any existing electrostatic
build-up. G
WARNING
Battery acid is caustic. There is a risk of injury.
Avoid contact with the skin, eyes or clothing.
Do not inhale any battery gases. Do not lean
over the battery. Keep children away from
batteries. Wash battery acid immediately with
water and seek medical attention.
! Have the battery checked regularly at a
qualified specialist workshop.
Observe the service intervals in the Service
Booklet or contact a qualified specialist
workshop for more information. !
Always have work on the battery carried
out at a qualified specialist workshop.
Should it, in exceptional circumstances, be
absolutely necessary to disconnectt he bat-
tery yourself, please observe the following:
R switch off the engine and remove the
key. Check that all the indicator lamps in
the instrumentc luster are off.Otherwise,
you may damage electroni ccomponents
such as the alternator, for example.
R first, disconnect the negative terminal
clamp, followed by the positive terminal
clamp. Never swap the terminal clamps.
The vehicle electronics may otherwise be
damaged.
R on vehicles with automatic transmission,
the transmission is locked in position P
after disconnecting the battery. The vehi-
cle is secured against rolling away.Y ou
can then no longer move the vehicle.
The battery and the cover of the positive
terminal clamp must be fitted securely dur-
ing operation.
! Have the battery checked and, if neces-
sary, replaced at a qualified specialist
workshop every two years or at least every
20,000 km. H
Environmental note Batteries contain pollutants.
It is illegal to dispose of them
with the household rubbish.
They must be collected sep-
arately and disposed of in an
environmentally responsible
recycling system. Dispose of batteries in an
environmentally responsible
manner
.Take discharged
batteries to a qualified spe-
cialis tworkshop or to a col-
lection point for used batter-
ies. 310
Battery (vehicle)Breakdown assistance

Do not use a rapid charging device to start the vehicle.
Make sure the jump leads are not damaged.
Make sure the jump leads are not touching any other metal objects when they are connected
to the battery.
If the indicator/warning lamps do not ligh tup at temperatures around or below freezing point,
the discharged battery is likely to be frozen (a commonplace scenario). In this case, do not
jump-start the vehicle or recharge the battery.
Once the battery has thawed out, its service life may be dramatically reduced.
The starting characteristic scan be impaired, particularly at low temperatures.
It is recommended that you have the thawed out battery checked at a qualified specialist
workshop.
Do no tuse a rapid charging device to start the vehicle. If your vehicle's battery is discharged,
the engine can be jump-started from another vehicle or from a second battery using jump
leads. Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible,
jump-start the vehicle using a second battery or ajump-starting device.
R Vehicles with apetrol engine: only jump-star tthe vehicle when the engine and exhaust
system are cold.
R Do not start the engine if the battery is frozen. Let the battery thaw first.
R Jump-starting may only be performed from batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected
for a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts
while the jump leads are connected to the battery.
R The jump leads cannot come into contact with parts such as the pulley or the fan. These
parts move when the engine is started and while it is running.
X Apply the parking brake.
X Move the selector lever to P.
X Switch off all electrical consumers (e.g. radio, blower, etc.).
X Open the bonnet (Y page 291).314
Jump-startingBreakdown assistance

Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-
starting device.
The jump-start terminal point consists of terminals ;and ?.
X Lift up cover :of positive terminal ;in the direction of the arrow.
X Connec tpositive terminal ;on your vehicle to positive terminal ?of donor battery B
using the jump lead. Begin with your own battery.
X Start the engine of the donor vehicle and run it at idling speed.
X Connect negative terminal Aof donor battery Bto earth point =of your vehicle using
the jump lead, connectingt he jump lead to donor battery Bfirst.
X Start the engine.
X First, remove the jump lead from earth point =and negative terminal A, 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.
i Jump-starting is not considered to be a normal operating condition.
i Jump-starting cables and further information regarding jump-starting can be obtained at
any qualified specialist workshop. Towing and tow-starting
Important safety notes
G
WARNING
The vehicle is braked when the HOLD function
or DISTRONIC PLUS is activated. Therefore, deactivate HOLD and DISTRONIC PLUS if the
vehicle is to be towed.
! You may tow the vehicle for a maximum
of 50km. A towing speed of 50 km/h must
not be exceeded. Towing and tow-starting
315Breakdown assistance Z

If the boiling point of the brake fluid is too low,
vapourp ockets may form in the brake system
when the brakes are applied hard (e.g. when
driving downhill). This impairs braking effi-
ciency.
You should have the brake fluid renewed at
regular intervals. The brake fluid change inter-
vals can be found in the Service Booklet.
Only use brake fluid approved by Mercedes-
Benz according to MB Approval 331.0.
Information about approved brake fluid can
be obtained at any qualified specialist work-
shop or on the Internet at:
http://bevo.mercedes-benz.com.
i Have the brake fluid regularly replaced at
a qualified specialist workshop. Coolant
Important safety notes G
WARNING
Antifreeze is highly flammable. Fire, naked
flames and smoking are prohibited when han-
dling antifreeze.
If antifreeze comes into contact with hot
engine parts, it may ignite and you could burn
yourself. Do not spill any antifreeze on hot
engine parts.
! Only add coolant that has been premixed
with the desired antifreez eprotection. You
could otherwise damage the engine.
Further information on coolants can be
found in the Mercedes-Benz Specifications
for Service Products, MB Specifications for
Service Products 310.1, e.g. on the Inter-
net 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.
! The engine cooling system is filled with
coolant, which must be renewed after
15 years or after 250,000 kilometres at the
latest.
The coolant is a mixture of water and anti-
freeze/corrosion inhibitor. It performs the
following tasks:
R anti-corrosio nprotection
R antifreeze protection
R raising the boiling point
If antifreeze/corrosion inhibitor is present in
the correct concentration, the boiling point of
the coolant will be around 130 †.
The antifreeze/corrosion inhibitor concentra-
tion in the engine cooling system should:
R be at least 50%. This will protect the engine
cooling system against freezing downto
approximately -3 7†.
R not exceed 55% (antifreeze protection
down to -45 †). Hea twill otherwise not be
dissipated as effectively.
If the vehicle has lost coolant, top it up with
equal amounts of water and antifreeze/cor-
rosio ninhibitor. Mercedes-Benz recom-
mends an antifreeze/corrosion inhibito rin
accordance with MB Specifications for
Service Products 310.1.
The coolan tis checked at every maintenance
interval at a qualified specialist workshop.
i When the vehicle is first delivered, it is fil-
led with a coolant mixture that ensures
adequate antifreeze and corrosion protec-
tion. Washer fluid
Important safety notes G
WARNING
Windscreen washer concentrate is highly
flammable. If it comes into contact with hot Service products and capacities
347Technical data
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