2012 MERCEDES-BENZ G-Class Owner's Manual

Problems with the fuel and fuel tank
Problem Possible causes/consequences and
M Solutions
Fuel is leaking from the
vehicle. G
Risk of explosion or fire
The fuel line or the fuel tank is defective.
X Turn the SmartKey to position
0 (Y
page
115) in the ignition lock
immediately and remove it.
X Do not restart the engine under any circumstances.
X Consult a qualified specialist workshop. The fuel filler flap
cannot be opened. The fuel filler flap is not unlocked.
or
The SmartKey batteries are discharged.
X
Unlock the vehicle (
Y page 60).
or
X Unlock the vehicle using the mechanical key ( Y page 61).
X Open the rear door.
X Manually unlock the fuel filler flap using the emergency release
(Y page 126). The fuel filler flap is unlocked, but the opening mechanism is
jammed.
X
Manually unlock the fuel filler flap using the emergency release
(Y page 126).
X Consult a qualified specialist workshop. Parking
Important safety notes
G
WARNING
Do not park this vehicle in areas where
combustible materials

can come into contact
with the hot exhaust system. Do not park the
vehicle on dry grassland or harvested grain
fields. Combustible materials, such as grass,
hay or leaves could be ignited by the hot
exhaust system and cause a vehicle fire. Unintended vehicle movement can cause
serious personal injury or damage to the
vehicle or the vehicle drivetrain. To reduce
such risks, always do the following before
turning
off

the engine and leaving the vehicle:
R keep your right foot on the brake pedal.
R engage the parking brake.
R shift the automatic transmission into park
position P.
R slowly release the brake pedal.
R when parked on an incline, always turn the
front wheels towards the road curb. Parking
127
Driving and parking
Z

R
turn the SmartKey in the ignition lock to
position 0 and remove the SmartKey from
the ignition lock.
R take the SmartKey with you and lock the
vehicle when leaving. Switching off the engine
G
WARNING
Do not turn off the engine before the vehicle
has come

to a complete stop. With the engine
not running, there is no power assistance for
the brake and steering systems. In this case,
it is important to keep in mind that a
considerably higher degree of effort is
necessary to brake and steer the vehicle. G
WARNING
Keep
in mind that turning off the engine alone
only will

shift the automatic transmission into
neutral position N automatically.
Always shift the automatic transmission into
park position P before turning off the engine.
Otherwise the vehicle could roll away which
could result in an accident and/or serious
personal injury.
X Shift the transmission to position P.
X Turn the SmartKey to position 0 in the
ignition lock and remove it.
The immobilizer is activated.
X Apply the parking brake firmly.
i The SmartKey

can only be removed if the
automatic transmission is in position P. Parking brake
G
WARNING
Engaging the parking brake while the vehicle
is in

motion can cause the rear wheels to lock
up. You could lose control of the vehicle and
cause an accident. In addition, the vehicle's
brake lights do not light up when the parking
brake is engaged. G
WARNING
When leaving the vehicle, always remove the
SmartKey from

the starter switch, take it with
you, and lock the vehicle. Do not leave
children unattended in the vehicle, or with
access to an unlocked vehicle. Children could
release the parking brake and/or shift the
automatic transmission out of park position
P, either of which could result in an accident
and/or serious personal injury. X
To apply: pull parking brake ;
up firmly.
When the

engine is running, the $ (USA
only) or J (Canada only) indicator lamp
lights up in the instrument cluster.
X To release: depress the brake pedal and
keep it depressed.
The selector lever lock is released.
X Pull parking brake ; up firmly.
X Press release button : on parking
brake ;
and

move the parking brake down
to the stop.
When the ignition is switched on or the
engine is running, the $ (USA only) or
J (Canada only) indicator lamp goes out
in the instrument cluster. Parking the vehicle for a long period
If you

leave the vehicle parked for longer than
four weeks, the battery may be damaged by
exhaustive discharge. 128
Parking
Driving and parking

X
Connect a trickle charger.
i You can obtain information about trickle
chargers from a qualified specialist
workshop.
If you
leave the vehicle parked for longer than
six weeks, the vehicle may suffer damage as
a result of lack of use.
X Visit a qualified specialist workshop and
seek advice. Driving tips
General driving tips
Important safety notes G
WARNING
Always remember that you must concentrate
primarily on driving the vehicle. The driver's
concentration must always be directed
primarily at road traffic. For your own safety
and that of others, we recommend that you
stop the vehicle at a safe place and in
accordance with

the traffic conditions before
making or accepting a phone call.
Comply with all legal requirements if you use
the telephone while driving. Use the hands-
free system and only use the telephone when
road, weather and traffic conditions permit. In
some jurisdictions, it is forbidden for drivers
to use mobile phones while driving.
Only operate COMAND (Cockpit Management
and Data System) in compliance with all legal
requirements and when the road, weather and
traffic conditions permit. You may otherwise
not be able to observe the traffic conditions,
endangering yourself and others.
Remember that your vehicle covers a distance
of 44 feet (approximately 14 m) a second
when it is traveling at only 30 mph
(approximately 50 km/h). Drive sensibly – save fuel Observe the following tips to save fuel:
X
The tires should always be inflated to the
recommended tire pressure.
X Remove unnecessary loads.
X Remove roof carriers when they are not
needed.
X Warm up the engine at low engine speeds.
X Avoid frequent acceleration or braking.
X Have all maintenance work performed at
the service intervals specified in the
Maintenance Booklet or indicated by the
service interval indicator.
Fuel consumption also increases when
driving in

cold weather, in stop-and-go traffic
and in mountainous terrain.
Drinking and driving G
WARNING
Drinking and driving and/or taking drugs and
driving are very dangerous combinations.
Even a small amount of alcohol or drugs can
affect your reflexes, perceptions and
judgment.
The possibility of a serious or even fatal
accident are

greatly increased when you drink
or take drugs and drive.
Do not drink or take drugs and drive or allow
anyone to drive who has been drinking or
taking drugs.
Pedals G
WARNING
Make sure absolutely no objects are
obstructing the pedals' range of movement.
Keep the driver's footwell clear of all
obstacles. If there are any floormats or
carpets in the footwell, make sure that the
pedals still have sufficient clearance.
During sudden driving or braking maneuvers,
the objects could get caught between the
pedals. You could then no longer brake or Driving tips
129
Driving and parking
Z

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

Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If your brake system is subject only to
moderate loads, you should test the
functionality of your brakes at regular
intervals
by
pressing firmly on the brake pedal
at high speeds. This improves the grip of the
brake pads.
You can find a description of Brake Assist
(BAS) on ( Y page 54).
High-performance brake system for
AMG vehicles The high-performance brake system is
installed only on the G 55 AMG.
G
WARNING
New vehicle brake pads and discs, and
replacement brake pads and discs may take
several hundred miles of driving until they
provide optimum

braking efficiency. Until that
time, you may need to use increased brake
pedal pressure while braking. Please be aware
of this and adjust your driving and braking
accordingly during this break-in period.
Excessive high-demand braking will cause
correspondingly high brake wear. Please be
attentive to the brake warning lamp in the
instrument cluster and brake condition
messages in the multifunction display.
Especially for high performance driving, it is
important to maintain and have the brake
system checked regularly.
The high-performance brake system is
designed for heavy loads. This may lead to
noise when braking. This will depend on:
R speed
R braking force
R environmental conditions, such as
temperature and humidity
The wear of individual components of the
brake system, such as the brake pads/linings
or brake discs, depends on the individual
driving style and operating conditions. For this reason, it is impossible to state a
mileage that will be valid under all
circumstances. An aggressive driving style
will
lead

to high wear. You can obtain further
information about this from your authorized
Mercedes-Benz Center.
Parking brake G
WARNING
While performing this procedure please
assure that the vehicle is stopped before
applying the parking brake. Otherwise the
rear wheels could lock up. You could lose
control of the vehicle and cause an accident.
In addition, the vehicle's brake lights do not
light up when the parking brake is engaged.
Make sure not to endanger any other road
users when you engage the parking brake.
If you drive on wet roads or dirt-covered
surfaces, road

salt and/or dirt could get into
the parking brake.
In order to prevent corrosion and a reduction
in the braking power of the parking brake,
observe the following:
R pull the parking brake upwards with the
release button depressed from time to time
before beginning the journey
(Y page 128).
R Drive a distance of approximately 110 yds
(100 m) with a maximum speed of 12 mph
(20 km/h). Driving on wet roads
Hydroplaning If water has accumulated to a certain depth
on the road surface, there is a danger of
hydroplaning occurring, even if:
R
you drive at low speeds.
R the tires have adequate tread depth.132
Driving tips
Driving and parking

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