2012 MERCEDES-BENZ G-Class check engine

Display messages Possible causes/consequences and
M Solutions? The engine fan is defective.
X
At coolant temperatures under 248 ‡ (120 † ), drive to the next
qualified specialist workshop.
X Avoid subjecting the engine to heavy loads, e.g. driving in
mountainous terrain, and stop-and-go traffic. # The battery is not being charged.
Possible causes are:
R
a defective alternator
R a torn poly-V-belt
R a malfunction in the electronics
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 Visit a qualified specialist workshop. The battery voltage is too low.
X
Switch off electrical consumers that are not required.
X Have the battery and alternator checked at a qualified specialist
workshop. The battery has been charged or the vehicle has been jump-
started.
X
Have the battery and alternator checked at a qualified specialist
workshop. 4
Check
oil

level at
next gas station. The engine oil level has dropped to a critical level.
X
Check the oil level (Y page 211).
X If necessary, add engine oil ( Y page 213).
X Have the engine checked for leaks if the engine oil needs to be
refilled more often than usual. You have added too much engine oil. There is a risk of damaging
the engine or catalytic converter.
X
Siphon off excess engine oil until it is at the specified level.
Observe the legal requirements.172
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M SolutionsThere is water in the engine oil.
X
Have the engine oil examined at a qualified specialist workshop. The measuring system is malfunctioning.
X
Visit a qualified specialist workshop. 4
Engine Oil Level
Service Required The engine oil level has dropped to a critical level.
X
Check the oil level (Y page 211).
X If necessary, add engine oil ( Y page 213).
X Have the engine checked for leaks if the engine oil needs to be
refilled more often than usual. You have added too much engine oil. There is a risk of damaging
the engine or catalytic converter.
X
Siphon off excess engine oil until it is at the specified level.
Observe the legal requirements. There is water in the engine oil.
X
Have the engine oil checked. 4
At next gas
station add
1.0
qt.
engine oil.
(USA only)At next
gas station add
1.0 liter engine
oil.(Canada only) The engine oil level is too low.
X
Check the oil level (Y page 211).
X If necessary, add engine oil ( Y page 213).
X Have the engine checked for leaks if the engine oil needs to be
refilled more often than usual. Information on approved engine oils can be obtained from any qualified specialist workshop
or on the Internet at
http://bevo.mercedes-benz.com

.
! The oil level is too low. Avoid long journeys with too little engine oil. There is a risk of
engine damage.
The display messages and the corresponding symbol that indicate that the oil level is too
low must not be ignored. Display messages
173
On-board computer and displays Z

Display messages Possible causes/consequences and
M Solutions4
Engine Oil Level
Stop, Turn Engine
Off The engine oil level is too low. There is a risk of engine damage.
X
Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Switch off the engine.
X Add engine oil ( Y page 213) and check the oil level
(Y page 211). 8
Reserve Fuel The fuel level has fallen below the reserve range. The fuel gauge's
needle does not move any further down. The operation of the
auxiliary heating can no longer be guaranteed.
X
Refuel at the nearest gas station. 8
Gas cap is open. The fuel system pressure is too low. The fuel filler cap is not closed
correctly or the fuel system is leaking.
X
Check that the fuel filler cap is correctly closed.
X If the fuel filler cap is not correctly closed:
close the fuel filler
cap.
X If the fuel filler cap is closed: visit a qualified specialist
workshop. ´
Clean Fuel Filter There is water in the fuel filter. The water must be drained off.
X
Visit a qualified specialist workshop. Driving systems
Display messages Possible causes/consequences and
M SolutionsAAS
Service Required
G
Risk of accident
AAS is not available due to a malfunction. The vehicle may roll
back on a gradient as soon as you remove your foot from the
accelerator pedal.
X Drive on carefully.
X Visit a qualified specialist workshop immediately. Cruise Cont.
Inoperative Cruise control is inoperative.
X
Visit a qualified specialist workshop.174
Display messages
On-board computer and displays

Display messages Possible causes/consequences and
M Solutions©
TC
Shift
Procedure
Canceled The gear change process was not carried out.
X
Repeat the gearshift process. ©
TC Shift
Conditions Not
Fulfilled One or more conditions to shift the transfer case have not been
fulfilled.
X
Repeat the gearshift process. ©
TC In Neutral The transfer case is in the neutral position.
X
Shifting the transfer case into HIGH or LOW.©
Transfer Case
Service Required 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. 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. Warning and indicator lamps in the instrument cluster
Seat belts
Problem Possible causes/consequences and
M Solutions7
After starting the
engine, the red seat
belt
warning

lamp lights
up for six seconds. The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.
X
Fasten your seat belt ( Y page 41).7
After starting the
engine, the red seat
belt
warning

lamp lights
up. In addition, a
warning tone sounds
for up to six seconds. G
Risk of injury
The driver's seat belt is not fastened.
X Fasten your seat belt ( Y page 41).
The warning tone ceases. 178
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Safety systems
Problem Possible causes/consequences and
M Solutions
$ (USA only)
J (Canada only)
The red brake system
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. $
(USA only)
J (Canada only)
The red brake system
warning lamp

comes on
while the engine is
running. G
Risk of accident
There is not enough brake fluid in the brake fluid reservoir.
X Pull
over and stop the vehicle safely as soon as possible, paying
attention to

road and traffic conditions. Do not continue driving
under any circumstances.
X Engage the parking brake.
X Consult a qualified specialist workshop immediately.
X Observe the additional display messages in the multifunction
display.
Do not add brake fluid. This will not rectify the malfunction. G
WARNING
Driving
with the brake warning lamp illuminated can result in an accident. Have your brake system
checked immediately

if the brake warning lamp stays on. 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. 180
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Problem Possible causes/consequences and
M Solutions!
The
yellow
ABS warning
lamp is lit while the
engine is running. G
Risk of accident
ABS (Anti-lock Brake System) is deactivated due to a malfunction.
Therefore, BAS

(Brake Assist), ESP ®
(Electronic Stability Program),
EBD (electronic brake force distribution) and 4ETS are also
deactivated.
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
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 defective, other systems, such as the
navigation system or the automatic transmission, may also be
unavailable. !
The
yellow

ABS warning
lamp is lit while the
engine is running. G
Risk of accident
The on-board voltage is too low. ABS has been deactivated due to
undervoltage.
ESP ®
, BAS, EBD and 4ETS are therefore also deactivated, for
example.
The brake

system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Switch off consumers that are not required, e.g. the rear window
defroster or interior lighting.
ABS will be available again as soon as the vehicle's on-board
electrical system voltage increases.
If the warning lamp is still on:
X Have the battery and alternator checked at a qualified specialist
workshop. !
The
yellow

ABS warning
lamp is lit while the
engine is running. You have engaged the differential locks. ABS, BAS, EBD, ESP
®
and
4ETS are deactivated.
X Disengage the differential locks.
Subsequently, ABS, BAS, EBD, ESP ®
and 4ETS are reactivated. Warning and indicator lamps in the instrument cluster
181
On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions$ (USA only)
J (Canada only)
!
The red brake system
warning lamp and the
yellow ABS warning
lamp are on while
driving. In addition, a
warning tone sounds
for about five seconds.
G
Risk of accident
EBD is faulty.
The brake
system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
X Drive on carefully.
X Visit a qualified specialist workshop. ÷
The yellow ESP
®
warning lamp flashes
while the vehicle is in
motion. G
Risk of accident
ESP ®
or traction control is intervening because there is a risk of
skidding or because at least one wheel has started to spin.
X When pulling away, only depress the accelerator pedal as far as
necessary.
X Ease off the accelerator pedal after pulling away.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
For exceptions: (

Y page 55).å
The yellow ESP
®
OFF
warning lamp

is lit while
the engine is running. G
Risk of accident
ESP ®
is deactivated. ESP ®
will not stabilize the vehicle if it starts
to skid or if a wheel starts to spin.
X Reactivate ESP ®
.
For exceptions: (
Y page 55).
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. 182
Warning and indicator lamps in the instrument cluster
On-board computer and displays

Problem Possible causes/consequences and
M Solutionså
The yellow ESP
®
OFF
warning lamp
is lit while
the engine is running. You have engaged the differential locks. ABS, ESP
®
, 4ETS and BAS
have been deactivated.
X Disengage the differential locks.
ESP ®
, 4ETS and BAS are subsequently reactivated.
X Observe the additional display messages in the multifunction
display. +
The red SRS warning
lamp is lit while the
engine is running.
G
Risk of injury
The restraint systems are malfunctioning. The air bags or ETDs
may either be triggered unintentionally or, in the event of an
accident, not be triggered at all.
X Drive on carefully.
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. Warning and indicator lamps in the instrument cluster
183
On-board computer and displays Z