ECU MERCEDES-BENZ G-CLASS SUV 2015 Owner's Guide

Engine
Display messagesPossible causes/consequences andMSolutions
?
Coolant Too Hot
Stop Vehicle
Switch Engine Off
The coolant is too hot.
A warning tone also sounds.
GWARNING
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury. X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Ypage 110).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X Do not start the engine again until the display message goes out
and the coolant temperature is below 248 ‡ (120 †). Other-
wise, the engine could be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visit a qualified specialist
workshop immediately.
Under normal operating conditions and with the specified coolant
level, the coolant temperature may rise to 248 ‡ (120 †).
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 Check the poly-V-belt.
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, the engine could be damaged.
X Pay attention to the coolant temperature display.
X Visit a qualified specialist workshop.
Display messages155
On-board computer and displays
Z

Driving systems
Display messagesPossible causes/consequences andMSolutions
TC shift condiZ
tionsnotfulfilled
Apply the brake/
parking brake
The parking brake has not been applied and the brake pedal has
not been depressed. The transfer case has canceled the gear
change process and is inNeutral. There is no connection between
the engine and the drive wheels.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Depress the brake pedal and apply the parking brake.
X Shift the automatic transmission to neutral position N.
X Make sure all conditions for changing gears are met(Y page 132).
X Repeat the gearshift process.
TC malfunction
Consult workshop
aboutapplyingthe
parking brake
There is a malfunction in the transfer case.
X Do not shift the transfer case.
X When parking, secure the vehicle against rolling away (Y page 110).
X Have the vehicle checked at a qualified specialist workshop.
TC shift canceled
Reactivate
The transfer case has not performed the gear change process. XRepeat the gearshift process.
X Make sure all conditions for changing gears are met (Y page 132).
TC shift condiZ
tionsnotfulfilled
Max. speed 25 mph
You have exceeded the maximum speed for the gearshift process.
X Drive more slowly.
X Repeat the gearshift process.
TC shift condiZ
tionsnotfulfilled
SelectNEUTRALgear
You have not met one or more shift conditions.
X Shift the automatic transmission to neutral position N.
X Repeat the gearshift process.
TC shift condiZ
tionsnotfulfilled
Max. speed 40 mph
You have exceeded the maximum speed for the gearshift process.
X Drive more slowly.
X Repeat the gearshift process.
LOW RANGE
ON
The transfer case is in the LOW RANGEoff-road position.
HIGH RANGE
ON
The transfer case is in the HIGH RANGEon-road position.
156Displaymessages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Differential lock
only available in
LOW RANGE
The LOW RANGE button has been pressed. The transfer case is in
the LOW RANGE off-road driving position and a differential lock is
engaged.
X Disengage the differential locks ( Ypage 134).
X Repeat the gearshift process.
TC NEUTRAL
ON
The transfer case is in the Neutralneutral position.
A warning tone will also sound when the driver's door is opened
and the brake pedal is not depressed.
X Close the driver's door.
X Secure the vehicle against rolling away ( Ypage 110).
X Shift the transfer case according to driving conditions(Y page 132).
Preselected difZ
ferential lock
ESP unavailable
A differential lock has been engaged. The differential gear has not
yet locked the respective differential. The activation indicator
lamp (yellow) ( Ypage 134) of the switch lights up.
ESP is unavailable.
ABS is still available.
Differential lock
active
ABS and ESP
unavailable
A differential lock was engaged and the differential gear has
locked the respective differential. The activation indicator lamp
(yellow) and function indicator lamp (red) ( Ypage 134) on the
switch light up.
ABS and ESP are unavailable.
Display messages157
On-board computer and displays
Z

Tires
Display messagesPossible causes/consequences andMSolutions
Check TiresThe tire pressure in one or more tires has dropped significantly.
The wheel position is displayed in the multifunction display.
A warning tone also sounds.
GWARNING
With tire pressures which are too low, there is a risk of the fol-
lowing hazards:
R they may burst, especially as the load and vehicle speed
increase.
R they may wear excessively and/or unevenly, which may greatly
impair tire traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Ypage 110).
X If there is a flat tire, inspect the tires ( Ypage 216).
X Check the tire pressure ( Ypage 235).
X If necessary, correct the tire pressure.
Warning Tire MalZ
function
The tire pressure in one or more tires has dropped suddenly. The
wheel position is shown in the multifunction display.
A warning tone also sounds.
GWARNING
If you drive with a flat tire, there is a risk of the following hazards:
R a flat tire affects the ability to steer or brake the vehicle.
R you could lose control of the vehicle.
R continued driving with a flat tire will cause excessive heat build-
up and possibly a fire.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Ypage 110).
X If there is a flat tire, inspect the tires ( Ypage 216).
158Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
h
TirePressureWarnZ
ing, Tire MalfuncZ
tion
The tire pressure in one or more tires has dropped suddenly. The
wheel position is shown in the multifunction display.
A warning tone also sounds.
GWARNING
If you drive with a flat tire, there is a risk of the following hazards:
R a flat tire affects the ability to steer or brake the vehicle.
R you could lose control of the vehicle.
R continued driving with a flat tire will cause excessive heat build-
up and possibly a fire.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Ypage 110).
X If there is a flat tire, inspect the tires ( Ypage 216).
h
CheckTirePressure
The tire pressure in one or more tires has dropped significantly.
The wheel position is shown in the multifunction display.
A warning tone also sounds.
GWARNING
With tire pressures which are too low, there is a risk of the fol-
lowing hazards:
R they may burst, especially as the load and vehicle speed
increase.
R they may wear excessively and/or unevenly, which may greatly
impair tire traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Ypage 110).
X If there is a flat tire, inspect the tires ( Ypage 216).
X Check the tire pressure ( Ypage 235).
X If necessary, correct the tire pressure.
Display messages159
On-board computer and displays
Z

Vehicle
Display messagesPossible causes/consequences andMSolutions
AThe rear door is open.
GWARNING
When the engine is running, exhaust gases can enter the vehicle
interior if the tailgate is open.
There is a risk of poisoning.
X Close the rear door.
?The hood is open.
GWARNING
The open hood may block your view when the vehicle is in motion.
There is a risk of an accident.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Ypage 110).
X Close the hood.
D
PowerSteeringMalZ
function.SeeOperZ
ator's Manual
The power steering is malfunctioning.
A warning tone also sounds.
GWARNING
You will need to use more force to steer.
There is a risk of an accident.
X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop.
Warning and indicator lamps in the
instrument cluster
General notes
This section describes indicator and warning
lamps in the instrument cluster relevant to
safety and solutions. A description of other
indicator and warning lamps in the instrument cluster and their solutions can be found in the
Digital Operator's Manual.
160Warning and indicator lamps in the instrument cluster
On-board computer and displays

Safety
Seat belts
ProblemPossible causes/consequences and MSolutions
ü
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a warn-
ing tone sounds for up
to six seconds.The driver's seat belt is not fastened.
X Fasten your seat belt ( Ypage 46).
The warning tone ceases.
ü
The red seat belt warn-
ing lamp lights up after
the engine starts, as
soon as the driver's or
the front-passenger
door is closed.The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt ( Ypage 46).
The warning lamp goes out.
There are objects on the front-passenger seat.
X Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out.
ü
The red seat belt warn-
ing lamp flashes and an
intermittent audible
warning sounds.The driver or front passenger has not fastened their seat belt. The
vehicle is being driven faster than 15 mph (25 km/h) or has briefly been driven faster than 15 mph (25 km/h). X Fasten your seat belt ( Ypage 46).
The warning lamp goes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. The vehicle is being
driven faster than 15 mph (25 km/h) or has briefly been driven
faster than 15 mph (25 km/h).
X Remove the objects from the front-passenger seat and stow
them in a secure place.
The warning lamp goes out and the intermittent warning toneceases.
Warning and indicator lamps in the instrument cluster161
On-board computer and displays
Z

Safety systems
ProblemPossible causes/consequences andMSolutions
$(USA only)
J (Canada only)
USA only: the red
brake system warning
lamp is lit while the
engine is running. A
warning tone alsosounds.
Canada only: the yel-
low brake system warn-
ing lamp is lit while the
engine is running. A
warning tone alsosounds.GWARNING
The brake boosting effect is malfunctioning and the braking char- acteristics may be affected.
There is a risk of an accident.
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 Secure the vehicle against rolling away ( Ypage 110).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display.
$ (USA only)
J (Canada only)
USA only: the red
brake system warning
lamp is lit while the
engine is running. A
warning tone alsosounds.
Canada only: the yel-
low brake system warn-
ing lamp is lit while the
engine is running. A
warning tone alsosounds.There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There is a risk of an accident.
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 Secure the vehicle against rolling away ( Ypage 110).
X Do not add brake fluid. Adding more will not remedy the mal-
function.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display.
162Warning and indicator lamps in the instrument cluster
On-board computer and displays

Engine
ProblemPossible causes/consequences andMSolutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.The coolant temperature has exceeded 248 ‡ (120 †). The air-
flow to the engine radiator may be blocked or the coolant level may
be too low.
GWARNING
The engine is not being cooled sufficiently and may be damaged.
Do not drive when your engine is overheated. This can cause some
fluids which may have leaked into the engine compartment to
catch fire.
Steam from the overheated engine can also cause serious burns
which can occur just by opening the hood.
There is a risk of injury. X Observe the additional display messages in the multifunction display.
X Pull over and stop the vehicle safely and switch off the engine,
paying attention to road and traffic conditions.
X Secure the vehicle against rolling away ( Ypage 110).
X Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and add coolant, observing the warning
notes ( Ypage 208).
X If you need to add coolant more often than usual, have the
engine coolant system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by snow, slush or ice.
X At coolant temperatures below 248 ‡ (120 †), 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.
168Warning and indicator lamps in the instrument cluster
On-board computer and displays

Tires
ProblemPossible causes/consequences andMSolutions
h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) is lit.
Canada only:
The yellow tire pressure
monitor warning lamp
(pressure loss) is lit.The tire pressure monitor has detected a loss of pressure in at
least one of the tires.
GWARNING
Tire pressures that are too low pose the following hazards:
R they may burst, especially as the load and vehicle speed
increase.
R they may wear excessively and/or unevenly, which may greatly
impair tire traction.
R the driving characteristics, as well as steering and braking, may
be greatly impaired.
There is a risk of an accident.
X Stop the vehicle without making any sudden steering or braking
maneuvers. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away ( Ypage 110).
X Observe the additional display messages in the multifunction
display.
X If there is a flat tire, inspect the tires ( Ypage 216).
X Check the tire pressure ( Ypage 235).
X If necessary, correct the tire pressure.
h
USA only:
The yellow tire pressure
monitor warning lamp
(pressure loss/
malfunction) flashes for
approximately one
minute and then
remains lit.The tire pressure monitor is faulty.
GWARNING
The system is possibly unable to recognize or register low tire
pressure.
There is a risk of an accident.
X Observe the additional display messages in the multifunction
display.
X Visit a qualified specialist workshop.
170Warning and indicator lamps in the instrument cluster
On-board computer and displays