2012 MERCEDES-BENZ G-CLASS SUV Owners Manual

Problem Possible causes/consequences and
M Solutions
!
The red ABS warning
lamp is lit while the
engine is running.
ABS (Anti-lock Brake System) has been deactivated due to a fault.
BAS (Brake Assist), ESP
®
(Electronic Stability Program), the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, for example, are therefore also deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop.
If the ABS control unit is faulty, there is also a possibility that other
systems, such as the navigation system or the automatic trans-
mission, will not be available. 254
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
!
The red ABS warning
lamp is lit while the
engine is running.
ABS is temporarily unavailable. BAS, ESP
®
,E BD (electronic brake
force distribution), the HOLD function, hill star tassist, ESP ®
trailer
stabilisation and the adaptive brake lights, for example, are there-
fore also deactivated.
Possible causes:
R Self-diagnosis is not yet complete.
R The on-board voltage may be insufficient.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
There is a risk of an accident.
X Carefully drive on a suitable stretch of road making slight steer-
ing movements at a speed above 20 km/h.
The functions mentioned above are available againw hen the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
255On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
!
The red ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds.
EBD is faulty. Therefore, ABS, BAS, ESP
®
, the HOLD function, hill
start assist, the adaptive brake lights and ESP ®
trailer stabilisation
are also not available, for example.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. !
The red ABS warning
lamp is lit while the
engine is running.
You have engaged the differential locks. ABS is deactivated.
X
Disengage the differential locks.
Subsequently ABS is reactivated. J֌!
The yellow brake warn-
ing lamp, the yellow
ESP ®
and ESP ®
OFF
warning lamps and the
yellow ABS warning
lamp are lit while the
engine is running. ABS and ESP
®
are malfunctioning. Therefore, BAS, EBD, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation, for example, are also not available.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The front and rear wheels could therefore
lock if you brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 256
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
÷
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. ESP
®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X Only depress the accelerator pedal as far as necessary when
pulling away.
X Accelerate more gently while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
Exceptions: (Y page 62) å
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. ESP
®
is deactivated.
G WARNING
If ESP ®
is switched off, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Reactivate ESP ®
.
Exceptions: (Y page 62)
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Have ESP ®
checked at a qualified specialist workshop. ֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, the HOLD function, hill start assist, the adaptive brake
lights and ESP ®
trailer stabilisation are not available due to a mal-
function.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
257On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
֌
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, the HOLD function, hill start assist and ESP ®
trailer
stabilisation are temporarily unavailable.
BAS and the adaptive brake lights may also have failed.
Self-diagnosis is not yet complete.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Carefully drive on a suitable stretch of road making slight steer-
ing movements at a speed above 20 km/h.
The functions mentioned above are available again when the
warning lamp goes out.
If the warning lamp is still on:
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. å
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. You have engaged the differential locks. ABS, ESP
®
,4 ETS and BAS
have been deactivated.
X Disengage the differential locks.
ESP ®
, 4ETS and BAS ar esubsequently reactivated.
X Observe the additional display messages in the multifunction
display. 258
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
!
The yellow parking
brake warning lamp
comes on while the
vehicle is moving. A
warning tone also
sounds.
You are driving with the parking brake applied.
X
Release the parking brake.
The warning lamp goes out and the warning tone ceases. 6
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint Sys-
tem).
G WARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
X Drive on carefully.
X Have SRS checked at a qualified specialist workshop immedi-
ately.
For further information about the Supplemental Restraint System,
see (Y page 39). Engine
Problem Possible causes/consequences and
M Solutions
;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running.
There may be a fault, for example:
R
in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop. ;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running.
Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 159).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need not be
checked. Warning and indicator lamps in the instrument cluster
259On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated when the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. %
On diesel engine vehi-
cles, the preglow indi-
cator lamp does not
light up when the key is
in position
2(Y
page 143). The preglow system is malfunctioning.
X
Visit a qualified specialist workshop immediately. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the
start of the scale.
The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X
Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Engage the parking brake.
X Consult a qualified specialist workshop. 260
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be mal-
functioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X
Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Engage the parking brake.
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 293).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
X Do not start the engine again until the coolant temperature is
below 120 †. The engine may otherwise be damaged.
X Drive to the nearest qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in moun-
tainous terrain, and stop-start driving. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine
is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
Steam from an overheated engine can cause serious burns which
can occur just by opening the bonnet.
There is a risk of injury.
X Observe the additional display messages in the multifunction
display.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 163).Warning and indicator lamps in the instrument cluster
261On-board computer and displays Z