2012 MERCEDES-BENZ G-Class check engine

Turn off the engine before refueling.
Whenever you are around gasoline, avoid
inhaling fumes and any skin or clothing
contact.
Direct skin contact with fuels and the
inhalation
of
fuel vapors are damaging to your
health. G
WARNING
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gasoline
to spray back out when removing the fuel
pump nozzle, which could cause personal
injury.
! Do not

use diesel to refuel vehicles with a
gasoline engine. Even small amounts of the
wrong fuel result in damage to the fuel
system and engine.
! Do not switch on the ignition if you
accidentally refuel with the wrong fuel.
Otherwise, the fuel will enter the fuel lines.
Notify a qualified specialist workshop and
have the fuel tank and fuel lines drained
completely. Gasoline
Fuel grade !
You should only refuel with unleaded
premium-grade gasoline as this avoids
damaging the catalytic converter.
If engine running problems are apparent,
have the cause checked immediately and
repaired. Excess unburned fuel can
otherwise enter the catalytic converter,
leading to overheating and possibly
causing a fire.
i Only refuel

with premium-grade unleaded
gasoline with a specified minimum octane
number of 91 (average value of 96 RON/
86 MON).
You will usually find information about the
fuel grade on the pump. If you cannot find the label on the gasoline pump, ask the gas
station staff.
You
can

find more information under "Fuel"
(Y page 273), by contacting an authorized
Mercedes-Benz Service Center or by
visiting http://bevo.mercedes-
benz.com.
! Use a filter when refueling from a fuel can.
Otherwise, the fuel lines and/or injection
system could be blocked by particles from
the fuel can. Refueling
Fuel filler flap When you open or close the vehicle with the
SmartKey, the fuel filler flap is automatically
unlocked or locked.
The position of the fuel filler cap
8
is
displayed in

the instrument cluster. The arrow
next to the filling pump indicates the side of
the vehicle. The fuel filler flap is located to the
rear on the right. Example: G 550 fuel filler cap
:
To open the fuel filler flap
; Tire pressure table
= Fuel type
? To insert the fuel filler cap
Opening X
Switch off the engine. Refueling
125
Driving and parking Z

i
When the engine is running and the fuel
filler flap is open, the yellow reserve fuel
warning lamp and the = (USA only)
or ; (Canada only) Check Engine
warning lamp may light up.
For further information on warning and
indicator lamps in the instrument cluster,
see ( Y page 184).
X Remove the SmartKey from the ignition
lock.
X Press the fuel filler flap in the direction of
arrow :.
The fuel filler flap opens slightly.
X Open the fuel filler flap.
X Turn the fuel filler cap counterclockwise
and remove it.
X Insert the fuel filler cap into the holder
bracket on the inside of filler flap ?.
X Completely insert the fuel pump nozzle into
the filler neck and refuel.
X Only fill the tank until the pump nozzle
switches off.
! Overfilling the
fuel tank could damage the
fuel system.
Closing X
Replace the fuel filler cap and turn it
clockwise. The fuel filler cap audibly
engages.
X Close the fuel filler flap.
i Close the

fuel filler flap before locking the
vehicle. A locking pin otherwise prevents
the fuel filler flap from closing after the
vehicle has been locked. Fuel filler flap emergency release
G
WARNING
Avoid contact with the vehicle walls as they
may contain sharp edges. Otherwise, you
could injure yourself while releasing the fuel
filler flap. The emergency release is located in the cargo
compartment, on the right-hand side when
viewed in the direction of travel, behind the
rear panel trim.
X
Open the rear door. X
Disconnect edge guard : on the door
pillar.
X Remove rear panel trim ;. X
Pull emergency release = in the direction
of the arrow.
The fuel filler flap is unlocked.
X Open the fuel filler flap.126
Refueling
Driving and parking

accelerate. This could lead to accidents and
injury.
Rolling with the engine switched off G
WARNING
There is no power assistance for the steering
and the

brake when the engine is not running.
Steering and braking requires significantly
more effort and you could lose control of the
vehicle and cause an accident as a result.
Do not turn off the engine while the vehicle is
in motion.
Exhaust check G
WARNING
Inhalation
of exhaust gas is hazardous to your
health. All exhaust gas contains carbon
monoxide (CO), and inhaling it can cause
unconsciousness and possible death.
Do not

run the engine in confined areas (such
as a garage) which are not properly ventilated.
If you think that exhaust gas fumes are
entering the vehicle while driving, have the
cause determined and corrected
immediately. If you must drive under these
conditions, drive only with at least one
window fully open at all times.
Certain engine systems are designed to keep
the level of poisonous components in exhaust
fumes within legal limits.
These systems only work at peak efficiency
when they are maintained exactly in
accordance with the manufacturer's
specifications. For this reason, all work on the
engine must be carried out only by qualified
and authorized Mercedes-Benz technicians.
The engine settings must not be changed in
any circumstances. Furthermore, all specific
service work must be carried out at regular
intervals and in accordance with the
Mercedes-Benz service requirements. Details
can be found in the Maintenance Booklet. Brakes
Important safety notes G
WARNING
On
slippery road surfaces, never downshift in
order to obtain braking action. This could
result in

drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km/h) vehicle
steering is adversely affected by the Off-road
ABS.
Downhill gradients !
On long and steep gradients, you must
reduce the load on the brakes by shifting
early to

a lower gear. This allows you to take
advantage of the engine braking effect and
helps avoid overheating and excessive
wear of the brakes.
When you take advantage of the engine
braking effect, a drive wheel may not turn
for some time, e.g. on a slippery road
surface. This could cause damage to the
drive train. This type of damage is not
covered by the Mercedes-Benz warranty.
Heavy and light loads G
WARNING
Depressing
the brake pedal constantly results
in excessive

and premature wear to the brake
pads.
It may also cause the brakes to overheat,
seriously impairing their effectiveness. It may
then not be possible to stop the vehicle in
sufficient time to avoid an accident.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately, but
drive on for a short while. This allows the
airflow to cool the brakes more quickly. 130
Driving tips
Driving and parking

Wet roads
G
WARNING
After driving in heavy rain for some time
without applying
the brakes or through water
deep enough to wet brake components, the
first braking action may be somewhat
reduced. You have to depress the brake pedal
more firmly. Maintain a safe distance from
vehicles in front.
After driving on a wet road or having the
vehicle washed, brake firmly while paying
attention to the traffic conditions. This will
warm up the brake discs, thereby drying them
more quickly and protecting them against
corrosion. G
WARNING
Make sure that you do not endanger other
road users when you apply the brakes.
Limited braking performance on salt-
treated roads G
WARNING
The layer of salt on the brake discs and the
brake pads/linings may cause a delay in the
braking effect, resulting in a significantly
longer braking distance, which could lead to
an accident.
To avoid this danger, you should:
R occasionally brake carefully, without
putting other road users at risk, when you
are driving on salted roads. This helps to
remove any salt that may have started to
build up on the brake discs and the brake
pads/linings.
R maintain a greater distance to the vehicle
ahead and drive with particular care.
R carefully apply the brakes at the end of a
trip and immediately after commencing a
new trip,

so that salt residues are removed
from the brake discs. Servicing the brakes G
WARNING
If brake pads or brake fluid other than those
recommended are used, the braking
properties of the vehicle can be degraded to
an extent that safe braking is substantially
impaired. This could result in an accident. G
WARNING
Make sure that you do not endanger other
road users when you apply the brakes.
! If the

brake warning lamp lights up in the
instrument cluster and you hear a warning
tone even though the parking brake has
been released, the brake fluid level may be
too low. Observe additional warning
messages in the multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked
immediately. Have this work carried out at
an authorized Mercedes-Benz Center.
! A function or performance test should
only be carried out on a 2-axle
dynamometer. If you are planning to have
the vehicle tested on such a dynamometer,
contact an authorized Mercedes-Benz
Center to obtain further information first.
Otherwise, you could damage the drive
train or the brake system.
! As the ESP ®
system operates
automatically, the engine and the ignition
must be switched off (the SmartKey must
be in position 0 or 1 in the ignition lock) if
the parking brake is tested on a brake
dynamometer (for a maximum of ten
seconds).
Braking applications triggered
automatically by ESP ®
may otherwise
seriously damage the brake system.
All checks and maintenance work on the
brake system must be carried out at a
qualified specialist workshop. Driving tips
131
Driving and parking Z

For this reason, in the event of heavy rain or
in conditions in which hydroplaning can
occur, you must drive in the following
manner:
R
lower your speed.
R avoid ruts.
R brake carefully.
Driving on flooded roads !
Do not drive through flooded areas.
Check the
depth of any water before driving
through it. Drive slowly through standing
water. Otherwise, water may enter the
vehicle interior or the engine compartment.
This can damage the electronic
components in the engine or the automatic
transmission. Water can also be drawn in
by the engine's air suction nozzles and this
can cause engine damage.
If you have to drive on stretches of road on
which water has collected, please bear in
mind that:
R the maximum permissible still water depth
is 50 cm.
R you should drive no faster than at walking
pace.
Off-road fording :
Fording depth, 20 in (50 cm)
The fording depth must not exceed 20 in
(50 cm)

when the vehicle is loaded and ready
to drive. !
The water depth must not exceed 20 in
(50 cm). Note that the possible fording
depth is less in flowing water.
i You may only drive through freshwater.
R Observe the

safety notes (Y page 134) and
the general notes (Y page 135) on off-road
driving.
R Establish how deep the water is and the
characteristics of the body of water before
fording.
R Switch off the auxiliary heating and the air-
conditioning system.
R Shift the transfer case to
LOW (Y page 145).
R Engage the differential locks, if necessary
(Y page 148).
R Restrict the shift range to 1 or 2
(Y page 121).
R Avoid high engine speeds.
R Enter and exit the water at a flat place and
at a steady walking pace.
! Under no circumstances should you
accelerate before entering the water. The
bow wave could cause water to enter and
damage the engine and other assemblies.
R Drive slowly and at an even speed through
the water.
R Do not stop and do not switch off the
engine.
! Do not open any of the vehicle's doors
while fording. Otherwise, water could get
into the vehicle interior and damage the
vehicle's electronics and interior
equipment.
R Water offers a high degree of resistance,
and the ground is slippery and in some
cases unstable. Therefore, it is difficult and
dangerous to pull away in the water.
R Ensure that a bow wave does not form as
you drive.
R Clean any mud from the tire tread after
fording.
R Apply the brakes to dry them after fording. Driving tips
133
Driving and parking Z

Winter driving
General notes G
WARNING
If the vehicle becomes trapped in snow,
ensure that snow is kept away from the
exhaust pipe and from around the vehicle as
long as the engine is running. Otherwise,
poisonous carbon monoxide (CO) may enter
the vehicle,
resulting in loss of consciousness
and even death.
To assure sufficient fresh air ventilation, open
a window slightly on the side of the vehicle
not facing the wind.
Have your vehicle winterproofed at a qualified
specialist workshop at the onset of winter.
Observe the notes in the "Winter operation"
section ( Y page 244).
Driving with summer tires Observe the notes in the "Winter operation"
section (
Y
page 244).
Slippery road surfaces G
WARNING
The outside temperature indicator is not
designed to serve as an ice-warning device
and is therefore unsuitable for that purpose.
Indicated temperatures just above the
freezing point

do not guarantee that the road
surface is free of ice. The road may still be icy,
especially in wooded areas or on bridges. G
WARNING
On
slippery road surfaces, never downshift in
order to obtain braking action. This could
result in

drive wheel slip and reduced vehicle
control. Your vehicle's ABS will not prevent
this type of control loss.
Do not engage the transfer case in position
LOW when driving on ice or packed snow. At
speeds below 18 mph (30 km/h) vehicle steering
is adversely affected by the Off-road
ABS.
Drive particularly carefully on slippery road
surfaces. Avoid

sudden acceleration, steering
and braking maneuvers. Do not use cruise
control.
If the vehicle threatens to skid or cannot be
stopped when moving at low speed:
X Shift the transmission to position N.
X Try to bring the vehicle under control using
corrective steering.
i For more information on driving with
snow chains, see ( Y page 245). G
WARNING
Make sure that you do not endanger other
road users when you apply the brakes. Off-road driving
Important safety notes G
WARNING
Grains of sand, particles of dirt and other
abrasive materials can enter the brake
system. This can lead to excessive wear and
unpredictable braking efficiency.
After the brakes have been exposed to dirty
conditions, have them checked and cleaned
at a

qualified specialist workshop. Otherwise,
there is a risk that braking power may be
insufficient in the event of an emergency, or
that the braking effect may be unpredictable. G
WARNING
Do
not load items on the basic carrier bars. It
may cause

instability during some maneuvers
which could result in an accident.
Drive slowly in unknown terrain. This will
make it easier to recognize unexpected
obstacles and avoid damage to the vehicle.
To help avoid the vehicle rolling over, never
turn it around on steep inclines. If the vehicle 134
Driving tips
Driving and parking

cannot complete the attempted climb, back it
down in reverse gear.
Do not drive along the side of a slope. The
vehicle might

otherwise rollover. If in doing so
the vehicle begins to show a tendency to roll,
immediately steer into a line of gravity
(straight up or downhill).
Never let the vehicle roll backwards in idle.
You may lose control of the vehicle if you use
only the service brake. For information on
driving downhill, see "Driving downhill". G
WARNING
Do not reduce the tire inflation pressure
before driving through sand. However, if you
do so, remember to correct the tire inflation
pressure before continuing your trip. Driving
with reduced

tire inflation pressure increases
the risk of losing control of the vehicle and
rolling over.
General notes Read
this section carefully before driving your
vehicle off-road.

Practice by driving over more
gentle off-road terrain first.
Familiarize yourself with the characteristics
of your vehicle and the gear shift operation
before driving through difficult terrain.
The following driving systems are specially
adapted to off-road driving:
R 4ETS ( Y page 56)
R transfer case (Y page 145)
R differential locks (Y page 148)
Observe the following notes:
R stop your vehicle and, if necessary, shift the
transfer case to LOW (Y page 145) before
driving off-road.
R engage the differential locks, if necessary
(Y page 148).
i ABS, 4ETS, ESP ®
and BAS are deactivated
when the differential locks are activated.
This allows the front wheels to lock briefly,
so that these can dig into a loose surface. However, please note that locked wheels
skid and can no longer steer.
R Check that items of luggage and loads are
stowed safely and are well secured
(Y page 192).
R Make sure

there is always sufficient ground
clearance to prevent damage to the
vehicle.
R Always keep the engine running and in gear
when driving on a downhill gradient.
R Always keep the engine running and in gear
when driving on a slope.
R Drive slowly and evenly, if necessary at a
walking pace.
R Ensure that the wheels are in contact with
the ground at all times.
R Drive with extreme care on unknown off-
road routes where visibility is poor. For
safety reasons, get out of the vehicle first
and survey the off-road route.
R Check the depth of water before fording
rivers and streams.
R When fording, do not stop and do not
switch off the engine.
R Look out for obstacles such as rocks, holes,
tree stumps and furrows.
R Always keep the doors, rear door, side
windows and the sliding sunroof closed
while the vehicle is in motion.
R Switch off cruise control.
R Do not stray from marked routes or paths.
R Adapt your speed to the terrain. The
rougher, steeper or more ruts on the
terrain, the slower your speed should be.
R Drive slowly and at an even speed through
the water. Ensure that a bow wave does not
form as you drive.
R On sand, drive quickly to overcome the
rolling resistance. Otherwise, the vehicle
could dig itself into the sand.
R Do not jump with the vehicle as this will
interrupt the vehicle's propulsion. Driving tips
135
Driving and parking Z

R
Avoid high engine speeds. Drive at
appropriate engine speeds (maximum
3000 rpm).
R Do not shift the automatic transmission to
transmission position N.
R Always check the vehicle for damage after
off-road driving.
i Information about retrofitting special all-
terrain tires is available from any
authorized Mercedes-Benz Center. H
Environmental note
Protection of the environment is of primary
importance. Treat nature with respect.
Observe all prohibiting signs.
Checklist before driving off-road X
Engine oil level: check the engine oil level
and add oil if necessary.
Only then does the engine receive enough
oil when the vehicle is standing on a steep
incline.
! If the engine oil warning lamp lights up
while the vehicle is in motion, stop the
vehicle in

a safe place as soon as possible.
Check the engine oil level. The engine oil
warning lamp warning must not be ignored.
Continuing the journey while the symbol is
displayed could lead to engine damage.
X Wheel-changing tool kit: check that the
jack is

working and make sure you have the
lug wrench, a robust tow cable and a folding
spade in the vehicle.
X Wheels and tires: check the tire tread
depth and tire pressure.
X Check for damage and remove any foreign
objects, e.g. small stones, from the
wheels/tires.
X Replace any missing valve caps.
X Replace dented or damaged wheels.
X Carry a sound spare wheel. Checklist after driving off-road G
WARNING
If you notice sudden significant vibrations or
unusual handling performance or if you
suspect that damage has occurred to the
vehicle, you should activate the hazard
warning lamps, gently reduce speed and
carefully head for an area that is located at a
safe distance from the road.
Check the tires and the underside of the
vehicle for damage. If the vehicle seems
unsafe, have the vehicle towed away to the
nearest Mercedes-Benz Center or tire dealer
to be repaired.
Driving over rough terrain places greater
demands on your vehicle than driving on
normal roads. After driving off-road, check
the vehicle.

This allows you to detect damage
promptly and reduce the risk of an accident
to yourself and other road users.
X Shift the transfer case to HIGH
(Y page 145).
X Disengage the differential locks
(Y page 148).
X Clean the headlamps and rear lights and
check for damage.
X Clean the front and rear license plates.
X Clean the wheels and tires with a water jet
and remove any foreign objects.
X Clean the wheels, tires, wheel arches and
the vehicle underside with a water jet;
check for

any foreign objects and damage.
X Check whether twigs or other parts of
plants have become trapped. These
increase the risk of fire and can damage
fuel pipes, brake hoses or the rubber
bellows of the axle joints and propeller
shafts.
X After the trip, examine without fail the
entire undercarriage,

wheels, tires, brakes,
bodywork structure, steering, chassis and
exhaust system for damage. 136
Driving tips
Driving and parking