2012 MERCEDES-BENZ G-Class check engine

X
After driving for extended periods across
sand, mud,
gravel, water or in similarly dirty
conditions, have the brake discs, wheels,
brake pads/linings and axle joints checked
and cleaned.
X If you notice strong vibrations after off-road
driving, check for foreign objects in the
wheels and drive train and, if necessary,
remove them. Foreign objects can disturb
the balance and cause vibrations.
X Test the brakes.
Driving on sand 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.
Observe the following rules when driving on
sand:
R shift the transfer case to
LOW (Y page 145).
R avoid high engine speeds.
R limit the shift range of the automatic
transmission according to the off-road
conditions.
R drive quickly to overcome the rolling
resistance. Otherwise, the vehicle could dig
itself into the sand.
R drive in the tracks of other vehicles if
possible. Make sure that the ruts are not
too deep, that the sand is firm enough and
that your vehicle has sufficient ground
clearance.
Tire ruts and gravel roads Observe the following rules when driving
along
ruts

in off-road terrain or on roads with
loose gravel: !
Check that the ruts are not too deep and
that your vehicle has sufficient clearance.
Otherwise, your vehicle could be damaged
or bottom out and get stuck.
R shift the transfer case to
LOW (Y page 145).
R avoid high engine speeds.
R observe the

safety notes (Y page 134) and
the general notes (Y page 135) on off-road
driving.
R restrict the shift range of the automatic
transmission to 1 (Y page 121).
R drive slowly.
R where ruts are too deep, drive with the
wheels of one side on the center grassy
area, if possible.
Driving over obstacles !
Obstacles could damage the floor of the
vehicle or components of the chassis. Ask
passengers for

guidance when driving over
large obstacles. The passenger should
always keep a safe distance from the
vehicle when doing so in order to avoid
injury as a result of unexpected vehicle
movements. After driving off-road or over
obstacles, check the vehicle for possible
damage, especially to the underbody and
the components of the chassis.
Observe the following rules when driving over
tree stumps, large stones and other
obstacles: Driving tips
137
Driving and parking Z

R
observe the safety notes (Y page 134) and
the general notes (Y page 135) on off-road
driving.
R shift the transfer case to
LOW (Y page 145).
R avoid high engine speeds.
R select shift range 1 (Y page 121).
R make sure that you have enough ground
clearance before driving across an
obstacle.
R drive very slowly.
R try to drive straight over the center of
obstacles: front wheel first, then rear
wheel.
! Drive with particular care when driving
over an obstacle while driving up or down
a steep slope.
The vehicle could otherwise tilt and slide
sideways or tip over. Traveling uphill
Approach/departure angle :
Approach/departure angle, front
; Approach/departure angle, rear : ;
G 550
37° 31°
G 55 AMG
33° 28° R
Observe the safety notes (Y page 134) and
the general notes (Y page 135) on off-road
driving.
R Do not drive at an angle on slopes, inclines
or gradients, but instead follow the direct
line of fall. The maximum gradient-climbing
capability of your vehicle is 80%, which
corresponds to an approach/departure
angle of 38°. Note that the vehicle's
gradient-climbing capability depends on
the off-road conditions.
R Before driving on extreme uphill and
downhill gradients, shift the transfer case
to LOW (Y page 145).
R Engage the differential locks, if necessary
(Y page 148).
R Drive slowly.
R Accelerate gently and make sure that the
wheels are gripping.
R Avoid high engine speeds, except when
driving on sandy and muddy routes with
high driving resistance.
R Avoid high engine speeds – drive at
appropriate engine speeds (no more than
3000 rpm).
R Use the braking power of the engine when
driving down a slope. Observe the engine
speed; do not overrev the engine.
i Further information on the maximum
engine speed can be found in the
"Tachometer" and "Technical data"
sections.
R Select a shift range appropriate to the
gradient.
R Before tackling steep downhill gradients,
select shift range 1 (Y page 121).
R Check the brakes after driving off-road for
a long time. G
WARNING
Never turn the vehicle around on steep
inclines. The vehicle might roll over. If the
vehicle cannot

complete the attempted climb,
back it down in reverse gear. 138
Driving tips
Driving and parking

i
Hill start assist will aid you when pulling
away on a hill.
For further information, see "Hill start
assist" ( Y page 117).
Maximum gradient-climbing capability On good road surface conditions, the
maximum
gradient-climbing
capability is 80%,
which corresponds to an approach/
departure angle of 38°. Note that the
vehicle's gradient-climbing capability
depends on the off-road conditions.
Accelerate carefully and make sure that the
wheels do not spin when driving on steep
terrain.
i If the load on the front axle is reduced
when pulling away on a steep uphill slope,
the front wheels have a tendency to spin.
4ETS detects this and brakes the wheels
accordingly. The rear wheel torque is
increased, making it easier to drive off.
Brow of hill When driving on an uphill gradient, reduce
pressure slightly on the accelerator
immediately
before

reaching the top of the hill
(do not shift the transmission to position N).
Use the vehicle's own impetus to drive over
the top of the hill.
This style of driving prevents:
R the vehicle from lifting off the ground on the
brow of a hill
R loss of traction
R the vehicle from traveling too quickly down
the other side
Driving downhill R
Before tackling steep downhill gradients,
select shift range 1 (Y page 121).
This way you use the engine's braking
effect to reduce the speed. If this is not
sufficient, brake gently. When doing so, make sure that the vehicle is facing in the
direction of the line of fall.
R Observe the notes on driving in
mountainous terrain (Y page 139).
R Drive slowly.
R Do not drive at an angle down steep
inclines. Steer

into the line of fall and drive
with the front wheels aligned straight.
Otherwise, the vehicle could slip sideways,
tip and roll over.
R Check that the brakes are working normally
after a long downhill stretch.
i The special off-road ABS(Y page 54)
enables accurate, brief and repeated
locking of the front wheels, causing them
to dig into the loose ground. Note that when
the front wheels are fully braked, they slide
easily over the surface of the ground,
making it difficult to steer. Driving systems
Cruise control
Important safety notes Cruise control maintains a constant road
speed for you. On long and steep downhill
gradients, especially if the vehicle is laden,
you must select shift range 1, 2 or 3 in good
time. By doing so, you will make use of the
braking effect of the engine, which relieves
the load on the brake system and prevents
the
brakes

from overheating and wearing too
quickly.
Use cruise control only if road and traffic
conditions make it appropriate to maintain a
steady speed for a prolonged period. You can
set any road speed above 20 mph
(30 km/h). G
WARNING
The cruise control is a convenience system
designed to assist the driver during vehicle
operation. The driver is and must always Driving systems
139
Driving and parking
Z

R
the automatic transmission is in selector
lever position N.
R you are driving no faster than 25 mph
(40 km/h).
You could otherwise damage the transfer
case.
X Push the transfer case switch to LOW.
When the shift procedure is complete, the
L transfer case position appears in the
multifunction display.
X Shift the transmission to position D.
From LOW to HIGH
! Only carry out the gear selection if:
R the engine is running.
R the vehicle is rolling.
R the automatic

transmission is in selector
lever position N.
R you are driving no faster than 43 mph
(70 km/h).
You could otherwise damage the transfer
case.
X Push the transfer case switch to HIGH.
When the shift procedure is complete, the
H transfer case position appears in the
multifunction display.
If the gear change is not completed, the
following messages could appear in the
display:
R TC shift conditions not fulfilled
You have not met one or more shift
conditions.
R TC in neutral
The transfer case has canceled the gear
change process and is in N. The N transfer
case position appears in the multifunction
display. G
WARNING
If the transfer case is in Neutral, the park
position P of the automatic transmission will not hold the vehicle. The parking brake must
be engaged to hold the vehicle in place.
R TC shift procedure canceled
The transfer case has not performed the
gear change process.
X Carry out the gear change process again.
Make sure to meet all conditions for
changing gears.
R Transfer case Consult workshop
There is

a malfunction in the transfer case.
X Do not shift the transfer case.
X Have the vehicle checked as soon as
possible at

a qualified specialist workshop.
Shifting to neutral G
WARNING
If the transfer case is in Neutral, the park
position P of the automatic transmission will
not hold the vehicle. The parking brake must
be engaged to hold the vehicle in place.
X Turn the SmartKey to position 2 in the
ignition lock.
X Apply the parking brake.
X Depress the brake pedal.
X Move the selector lever to
position N (Y page 120).
X Push the transfer case switch to LOW for
about 30 seconds.
When the shift procedure is complete, the
N transfer case position appears in the
multifunction display.
i If the transfer case is in N, the SmartKey
is in the ignition lock and you open the
driver's door,

the TC in neutral message
appears in the multifunction display. If you
then release the parking brake, a warning
tone will sound. Off-road driving systems
147
Driving and parking Z

Useful information
i This Operator's Manual describes all
models and all standard and optional
equipment of your vehicle available at the
time of publication of the Operator's
Manual. Country-specific differences are
possible. Please
note that your vehicle may
not be equipped with all features
described. This also applies to safety-
related systems and functions.
i Please read the information on qualified
specialist workshops (Y page 20). Important safety notes
You will find an illustration of the instrument
cluster in the "At a glance" section
(
Y page 25).
G
WARNING
A driver's attention to the road and traffic
conditions must always be his/her primary
focus when driving.
For your safety and the safety of others,
selecting features through the multifunction
steering wheel should only be done by the
driver when

traffic and road conditions permit
it to be done safely.
Bear in mind that at a speed of just 30 mph
(approximately 50 km/h ), your vehicle is
covering a distance of 44 feet (approximately
14 m) every second. G
WARNING
No messages will be displayed if either the
instrument cluster or the multifunction
display is inoperative.
As a result, you will not be able to see
information about your driving conditions,
such as
R speed
R outside temperature
R warning/indicator lamps R
malfunction/warning messages
R failure of any systems
Driving characteristics may be impaired.
If you

must continue to drive, do so with added
caution. Contact an authorized Mercedes-
Benz Center as soon as possible. G
WARNING
Malfunction and warning messages are only
displayed for certain systems and are
intentionally not very detailed. The
malfunction and warning messages are
simply a reminder with respect to the
operation of certain systems. They do not
replace the owner's and/or driver's
responsibility to maintain the vehicle's
operating safety. Have all required
maintenance services and safety checks
performed on

the vehicle. Bring the vehicle to
an authorized Mercedes-Benz Center to
address the malfunction and warning
messages. Displays and operation
Tachometer
The red

band in the tachometer indicates the
engine's overrevving range.
! Do not drive in the overrevving range, as
this could damage the engine.
The fuel supply is interrupted to protect the
engine when the red band is reached. Displaying the coolant temperature
G
WARNING
Driving when your engine is overheated can
cause some

fluids which may have leaked into
the engine compartment to catch fire. You
could be seriously burned.
Steam from an overheated engine can cause
serious burns which can occur just by opening 152
Displays and operation
On-board computer and displays

G
WARNING
Driving with the message
Check
Brake
Fluid Level displayed can result in an accident. Have
your brake system checked immediately.
Do not add brake fluid before checking the brake system. Overfilling the brake fluid reservoir can
result in spilling brake fluid on hot engine parts and the brake fluid catching fire. You can be
seriously burned. Display messages Possible causes/consequences and
M
Solutions
#
Brake Wear The brake pads/linings have reached their wear limit.
X
Have the brake pads/linings replaced as soon as possible at a
qualified specialist workshop. G
Tele Aid
Inoperative USA only: one or more main functions of the mbrace system are
malfunctioning.
Canada only: one or more main functions of the TELEAID system
are malfunctioning.
X
USA only: have the mbrace system checked at a qualified
specialist workshop.
X Canada only: have the TELEAID system checked at a qualified
specialist workshop. +
Restraint System
Malfunction
Service Required G
Risk of injury
The restraint systems are malfunctioning.
X Visit a qualified specialist workshop immediately. G
WARNING
In the event a malfunction of the SRS is indicated as outlined above, the SRS may not be
operational.
For your safety, we strongly recommend that you contact an authorized Mercedes-Benz Center
immediately to

have the system checked. Otherwise the SRS may not be activated when needed
in an accident, which could result in serious or fatal injury, or it might deploy unexpectedly and
unnecessarily which could also result in injury. Display messages
167
On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutionsb
Reversing lamp
right The backup lamp is faulty.
X
Replace the bulb ( Y page 94).b
Tail lamp left
Back-up bulb on
 or 
Tail lamp right
Back-up bulb on The left or right-hand tail lamp is faulty. Another lamp has taken
over its function.
X
Replace the bulb ( Y page 98).Engine
Display messages Possible causes/consequences and
M Solutions; Some electronic systems are unable to send information to the
on-board computer. The coolant temperature gauge and the
tachometer could be malfunctioning.
X
Visit a qualified specialist workshop. +
Top
Up
Coolant See
Operator's Manual The coolant level is too low.
X
Add coolant, following the warning notes when doing so
(Y page 213).
X If coolant needs to be added more often than usual, have the
engine coolant system checked at a qualified specialist
workshop. G
WARNING
Do not spill antifreeze on hot engine parts. Antifreeze contains ethylene glycol which may burn
if it comes into contact with hot engine parts. You could be seriously burned.
! The coolant

level is too low. Avoid making long journeys with too little coolant in the cooling
system. The engine will otherwise be damaged.
The display messages and the corresponding symbol that indicate that the coolant level is
too low must not be ignored. 170
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M Solutions?
Coolant
Stop,
Turn
Engine Off The coolant is too hot.
X
Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Make sure that the air supply to the radiator is not blocked, e.g.
by snow, slush or ice.
X Wait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately. The poly-V-belt may have torn.
X
Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Open the hood.
X Check whether the poly-V-belt is torn.
If the poly-V-belt is torn:
! Do not

continue driving. The engine could otherwise overheat.
X Consult a qualified specialist workshop.
If the poly-V-belt is not damaged:
X Wait until the display message disappears before restarting the
engine. Otherwise, there is a risk of engine damage.
X Pay attention to the coolant temperature display.
X Visit a qualified specialist workshop. G
WARNING
Driving when your engine is overheated can cause some fluids which may have leaked into the
engine compartment to catch fire. You could be seriously burned.
Steam from

an overheated engine can cause serious burns which can occur just by opening the
engine hood. Stay away from the engine if you see or hear steam coming from it.
Stop the vehicle in a safe location away from other traffic. Turn off the engine, get out of the
vehicle and do not stand near the vehicle until the engine has cooled down.
! If the coolant temperature exceeds 248 ‡(120 †) do not continue driving. The engine will
otherwise be damaged. Display messages
171
On-board computer and displays Z