2012 MERCEDES-BENZ G-Class check engine

G
WARNING
The SRS self-check has detected a
malfunction if the + SRS indicator lamp:
R does not light up at all
R does not go out after approximately four
seconds after the engine is started
R lights up

after the engine is started or while
the vehicle is in motion
For your safety, Mercedes-Benz strongly
recommends that you have the system
checked as soon as possible at a qualified
specialist workshop. SRS may otherwise fail
to activate when it is needed in the event of
an accident, which could lead to serious or
fatal injuries. SRS might also be activated
unexpectedly and unnecessarily, which could
also result in injury.
In addition, work carried out improperly on
SRS may render SRS inoperative or cause
unintended air bag deployment. Work on the
SRS system should only be carried out by
qualified specialist personnel. Consult a
qualified specialist workshop.
If it is necessary to modify an air bag system
to accommodate a person with disabilities,
contact an authorized Mercedes-Benz Center
for details. USA only: for further information,
contact our Customer Assistance Center at
1-800-FOR-MERCedes (1-800-367-6372).
Safety guidelines for seat belts,
Emergency Tensioning Devices (ETDs)
and air bags G
WARNING
R Damaged seat

belts or seat belts that have
been subjected to stress in an accident
must be replaced. Their anchoring points
must also be checked. Only use seat belts
installed or supplied by an authorized
Mercedes-Benz Center.
R Air bags and pyrotechnic Emergency
Tensioning Devices (ETDs) contain
perchlorate material, which may require
special handling and regard for the environment.
Check your national disposal
guidelines. California residents, see
www.dtsc.ca.gov/HazardousWaste/
Perchlorate/index.cfm.
R Air bags

and ETDs are designed to function
on a one-time-only basis. An air bag or ETD
that has deployed must be replaced.
R Do not pass seat belts over sharp edges.
They could tear.
R Do not make any modification that could
change the effectiveness of the seat belts.
R Do not bleach or dye seat belts as this may
severely weaken them. In a crash they may
not be able to provide adequate protection.
R No modifications of any kind may be made
to any components or wiring of the SRS.
R Do not change or remove any component
or part of the SRS.
R Do not install additional trim material, seat
covers, badges, etc. over the steering
wheel hub, front-passenger front air bag
cover, outer sides of the seat backrests,
door trim panels, or door frame trims.
R Do not install additional electrical/
electronic equipment on or near SRS
components and wiring.
R Keep area between air bags and occupants
free of objects (e.g. packages, purses,
umbrellas, etc.).
R Do not hang items such as coat hangers
from the coat hooks or handles over the
door. These items may be thrown around in
the vehicle and cause head and other
injuries when the window curtain air bag is
deployed.
R Air bag system components will be hot after
an air bag has inflated. Do not touch them.
R Never place your feet on the instrument
panel, dashboard, or on the seat. Always
keep both feet on the floor in front of the
seat.
R Improper repair work on the SRS creates a
risk of rendering the SRS inoperative or
causing unintended air bag deployment.
Work on the SRS must therefore only be Occupant safety
33
Safety
Z

Driver's air bag
: deploys in front of the
steering wheel; front-passenger front air
bag ; deploys
in front of and above the glove
box.
They are deployed:
R in the event of certain frontal impacts
R if the system determines that air bag
deployment can offer additional protection
to that provided by the seat belt
R depending on whether the seat belt is being
used
R independently of other air bags in the
vehicle
If the vehicle overturns, the front air bags are
generally not deployed unless the system
detects high vehicle deceleration in a
longitudinal direction.
Your vehicle has an adaptive, two-stage
driver's air bag. In the event of a collision, the
air bag control unit evaluates the vehicle
deceleration. When the first deployment
threshold is reached, the front air bag is filled
with enough propellant gas to reduce the risk
of injuries. The front air bag is fully deployed
if a second deployment threshold is exceeded
within a few milliseconds.
The front air bags will not deploy in impacts
with vehicle deceleration or acceleration
rates which do not exceed the system’s
preset deployment thresholds for vehicle
deceleration or acceleration. You will then be
protected by the fastened seat belt. The front-passenger front air bag will only
deploy if:
R
the front-passenger seat is occupied.
R the 45 indicator

lamp in the center
console is not lit (Y page 37).
R the impact exceeds a preset deployment
threshold.
The front-passenger air bag is automatically
activated and deactivated. Both driver and
passenger should always check whether the
front-passenger air bag is activated or
deactivated.
The deployment of the driver's air bag does
not mean that the front-passenger air bag will
also deploy. If the system recognizes that the
front-passenger seat is empty, the front-
passenger air bag does not deploy even if the
impact fulfills the criteria and the driver's air
bag has deployed.
If the front-passenger seat is recognized as
occupied, the 45 indicator lamp lights
up for approximately six seconds if
R you turn the SmartKey to position 1 or 2 in
the ignition lock.
R the engine is running and then you switch
it off.
This indicates the operational readiness of
the front-passenger air bag.
Note that objects placed on the front-
passenger seat may cause the system to
recognize the seat as occupied. This can
result in the deployment of the front-
passenger air bag if the impact fulfills the
specified criteria. If the 45 indicator
lamp is lit up, the front-passenger air bag is
deactivated and will not deploy should the
situation arise. If indicator lamp 45 is
not lit up, the front-passenger air bag is
activated and will deploy should the situation
arise. G
WARNING
Your vehicle is equipped with air bag
technology which disables the front- 36
Occupant safety
Safety

Problems with the SmartKey
Problem Possible causes/consequences and
M Solutions
You cannot lock or
unlock the vehicle
using the SmartKey. The SmartKey battery is discharged or nearly discharged.
X
Point the tip of the SmartKey at the driver's door handle from a
distance of approximately 1.5 ft (50 cm) and try to unlock or
lock the vehicle again.
If this does not work:
X Check the SmartKey battery and replace it if necessary
(Y page 62).
X Lock or unlock the vehicle using the mechanical key
(Y page 66). The SmartKey is faulty.
X
Lock or unlock the vehicle using the mechanical key
( Y page 66).
X Have the SmartKey checked at a qualified specialist workshop. You have lost a
SmartKey. X
Have the SmartKey canceled at an authorized Mercedes-Benz
Center.
X Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. You have lost the
mechanical key. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. The SmartKey cannot
be
turned

in the ignition
lock. The SmartKey has been in position
0
for a considerable time.
X Remove the SmartKey and reinsert it into the ignition lock.
X Check the battery and charge it if necessary ( Y page 231).
X Start the engine. The on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to turn the SmartKey again.
If this does not work:
X Check the battery and charge it if necessary ( Y page 231).
or
X Jump-start the vehicle (Y page 233).
or
X Consult a qualified specialist workshop.64
SmartKey
Opening/closing

X
To switch on manually: turn the
SmartKey to position 2 in the ignition lock
or start the engine.
X Briefly press button : of the headlamp
cleaning system.
The headlamps are cleaned with a high-
pressure water jet. Cornering light function
The cornering light function improves the
illumination of the road over a wide angle in
the direction
you are turning, enabling better
visibility in tight bends, for example. It can
only be activated if the low-beam headlamps
are switched on and the fog lamp is switched
off.
Active: if you are driving at speeds below
25 mph(40 km/h) and switch on the turn
signals and turn the steering wheel.
Not active: if you are driving at speeds above
25 mph(40 km/h) or switch off the turn signal
and turn the steering wheel to the straight-
ahead position.
The cornering lamp may remain lit for a short
time. Headlamps and indicator lamps
fogged up on the inside
The headlamps

and the indicator lamps in the
exterior mirrors may fog up on the inside if
there is high atmospheric humidity. X
Drive with the headlamps switched on.
The level of moisture diminishes,
depending on

the length of the journey and
the weather conditions (humidity and
temperature).
If the level of moisture does not diminish:
X Have the headlamps checked at a qualified
specialist workshop. Interior lighting
Overview of interior lighting
Front overhead control panel
:
t To switch the cargo compartment
lamp/rear interior lighting on/off
; p Switches the right-hand reading
lamp on/off
= Rocker switch (to control the interior
lighting)
? p Switches the left-hand reading lamp
on/off 92
Interior lighting
Lights and windshield wipers

otherwise fog up as, in air-recirculation
mode,
no
fresh air is drawn into the vehicle.
R Use the residual heat function if you want
to heat or ventilate the vehicle interior
when the ignition is switched off. The
"residual heat" function can only be
activated or deactivated with the ignition
switched off.
R At very low temperatures, the rear window
defroster is only switched on once the
vehicle interior has warmed up. Activating/deactivating climate
control
Important information G
WARNING
When the climate control system is
deactivated, the outside air supply and
circulation are also deactivated. Only choose
this setting for a short time. Otherwise the
windows could

fog up, impairing visibility and
endangering you and others.
i Switch on climate control primarily using
the à button ( Y page 107).
Activating/deactivating X
Turn the SmartKey to position 2 in the
ignition lock.
X To switch on:
turn
control : clockwise to
the desired position (except position 0)
(Y page 105).
X The previously selected settings come into
effect again.
X To switch off: turn control : counter-
clockwise to position 0(Y page 105). Activating/deactivating the cooling
with air dehumidification function
Important information The cooling with air dehumidification function
is only available when the engine is running.
The air inside the vehicle is cooled and
dehumidified according to the temperature
selected.
G
WARNING
If you switch off the cooling function, the
vehicle will not be cooled when weather
conditions are

warm. The windows can fog up
more quickly. Window fogging may impair
visibility and endanger you and others.
Condensation may drip from the underside of
the vehicle when it is in cooling mode. This is
normal and not a sign that there is a
malfunction.
i The cooling with air dehumidification
function uses refrigerant R134a. This
coolant does not contain
chlorofluorocarbons, and therefore does
not damage the ozone layer.
Activating/deactivating !
If the cooling with air dehumidification
does not switch on, it is possible that the
climate control system has lost coolant.
Have the cooling with air dehumidification
checked at

a qualified specialist workshop.
X To activate: press the Á button.
The indicator

lamp in the Á button lights
up.
X To switch off: press the Á button.
The indicator

lamp in the Á button goes
out. The cooling with air dehumidification
function has a delayed switch-off feature. 106
Operating the climate control system
Climate control

on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal.
! Warm up the engine quickly. Do not use
the engine's full performance until it has
reached operating temperature.
Only shift the automatic transmission to
the desired
drive position when the vehicle
is stationary.
Where possible, avoid spinning the drive
wheels when pulling away on slippery
roads. You could otherwise damage the
drive train.
! Avoid high engine speeds when the
engine is cold. The engine's service life
could otherwise be significantly shortened.
Do not use the engine's full performance
until it has reached operating temperature. SmartKey positions
g
To remove the SmartKey
1 Power supply for some consumers, such
as the windshield wipers
2 Ignition (power supply for all consumers)
and drive position
3 To start the engine i
You can only remove the SmartKey if:
R the SmartKey is in position
0 in the
ignition lock.
R the automatic transmission selector
lever is in P.
As soon

as the ignition is switched on, all the
indicator lamps in the instrument cluster light
up. If an indicator lamp does not go out after
the engine is started or if it lights up while the
vehicle is in motion, see ( Y page 180).
If the SmartKey is in position 0 in the ignition
lock for an extended period of time, it can no
longer be turned in the ignition lock. The
steering is then locked. To unlock, remove the
SmartKey and reinsert it into the ignition lock.
The steering is locked when you remove the
SmartKey from the ignition lock.
X Remove the SmartKey when the engine is
switched off.
The starter battery could otherwise be
discharged.
If you cannot turn the SmartKey in the ignition
lock, the starter battery may not be charged
sufficiently.
X Check the starter battery and charge if
necessary ( Y page 231).
or
X Jump-start the vehicle (Y page 233). Starting the engine
Important safety notes 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 Driving
115
Driving and parking
Z

Problem Possible causes/consequences and
M SolutionsThe engine is not
running smoothly and
is misfiring. There is a malfunction in the engine electronics or a mechanical
component of the engine management system.
X
Only depress the accelerator pedal slightly.
X Have the cause rectified immediately at a qualified specialist
workshop.
Otherwise, non-combusted fuel may get into the catalytic
converter and damage it. The coolant
temperature gauge
shows a value above
248 ‡
(120 †).
Additionally, a display
message
may appear in
the multifunction
display and a warning
tone may sound. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X
Stop as soon as possible and allow the engine and the coolant
to cool down.
X Check the coolant level (Y page 213). Observe the warning
notes as you do so and add coolant if necessary. Automatic transmission
Important safety notes
G
WARNING
It is dangerous to shift the automatic
transmission out of parking position P or
neutral position N if the engine speed is
higher than

idle speed. If your foot is not firmly
on the brake pedal, the vehicle could
accelerate quickly forward or in reverse. You
could lose control of the vehicle and hit
someone or something. Only shift into gear
when the engine is idling normally and when
your right foot is firmly on the brake pedal. 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 loss of control. 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.
i Bear in mind that the power transmission
between the engine and the transmission
is interrupted when the engine is switched
off. Therefore, to prevent the vehicle from
rolling away, shift the automatic
transmission to position P and apply the
parking brake when the engine is switched
off and the vehicle is stationary. Automatic transmission
119
Driving and parking Z

Problems with the automatic transmission
Problem Possible causes/consequences and
M Solutions
The acceleration ability
is deteriorating.
The transmission no
longer changes gear. The transmission is in emergency mode.
It is only possible to shift into
second
gear and reverse gear.
X Stop the vehicle.
X Shift the transmission to position P.
X Turn the SmartKey to position 0 in the ignition lock.
X Wait at least ten seconds before restarting the engine.
X Shift the transmission to position D or R.
If D
is

selected, the transmission shifts into second gear; if R is
selected, the transmission shifts into reverse gear.
X Have the transmission checked at a qualified specialist
workshop immediately. You hear a warning
tone. You have:
R
switched off the engine
R opened the driver's door
R not moved the selector lever to position P
X Move the selector lever to
P.
Releasing the parking lock manually
In the

event of a malfunction, it is possible to
release the selector lever lock manually to
move it out of position P, e.g. if you wish to
have the vehicle towed. X
Apply the parking brake.
X Insert a suitable implement :
into the
opening protected by the flap. X
Press implement : downwards and
simultaneously move

the selector lever out
of position P.
X Remove implement :.
The selector

lever can now be moved freely
until it is returned to position P.
i The protective

flap only closes completely
if you briefly press to selector lever towards
D-. Refueling
Important safety notes
G
WARNING
Gasoline is highly flammable and poisonous.
It burns violently and can cause serious
personal injury.
Never allow sparks, flames or smoking
materials near gasoline. 124
Refueling
Driving and parking