malfunction MERCEDES-BENZ GL-Class 2014 X166 Repair Manual

Display messages Possible causes/consequences and
M
MSolutions Tire Press.Monitor
Tire Press.Monitor
Currently Currently
Unavailable Unavailable Due to a source of radio interference, no signals can be received
from the wheel sensors. The tire pressure monitor is temporarily
malfunctioning.
X
Drive on.
The tire pressure monitor restarts automatically as soon as the
problem has been solved. TirePress. TirePress.
Sensor(s) Missing Sensor(s) Missing There is no signal from the tire pressure sensor of one or several
wheels. The pressure of the affected tire is not displayed in the
multifunction display.
X
Have the faulty tire pressure sensor replaced at a qualified
specialist workshop. Tire Pressure Tire Pressure
Monitor Monitor
Inoperative No Inoperative No
Wheel Sensors Wheel Sensors The wheels mounted do not have a suitable tire pressure sensor.
The tire pressure monitor is deactivated.
X
Mount wheels with suitable tire pressure sensors.
The tire pressure monitor is activated automatically after driving
for a few minutes. Tire Tire
Press.
Press. Monitor
Monitor
Inoperative
Inoperative The tire pressure monitor is faulty.
X
Visit a qualified specialist workshop. Vehicle
Display messages Possible causes/consequences and
M MSolutions Shift to 'P' or
Shift to 'P' or
'N' 'N'
to
toStart
Start Engine
Engine You have attempted to start the engine with the transmission in
position
Ror D.
X Shift the transmission to position Por N. Auxiliary Battery Auxiliary Battery
Malfunction Malfunction The auxiliary battery for the automatic transmission is no longer
being charged.
X
Visit a qualified specialist workshop at the next opportunity.
X Until then, set the automatic transmission to position Pbefore
you switch off the engine.
X Before leaving the vehicle, apply the electric parking brake.
X Secure the vehicle against rolling away ( Ypage 188). Apply Brake to Apply Brake to
Shift from 'P' Shift from 'P' You have attempted to move the transmission selector lever to
position
D,Ror Nwithout depressing the brake pedal.
X Depress the brake pedal. 320
Display
messagesOn-board computer and displays

Display messages Possible causes/consequences and
M
MSolutions Transmission Not
Transmission Not
in P Risk of in P Risk of
Vehicle Rolling Vehicle Rolling
Away Away The driver's door is open and the transmission is in position
R,N
or D.
A warning tone also sounds.
X Shift the transmission to position P.
X Secure the vehicle against rolling away ( Ypage 188). Service Required Service Required
Do Do
Not
Not Shift
Shift Gears
Gears
Visit Dealer
Visit Dealer You cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position
Dis selected:
X Drive to a qualified specialist workshop without shifting the
transmission from position D.
If transmission position R,Nor Pis selected:
X Notify a qualified specialist workshop or breakdown service. Only Shift to 'P' Only Shift to 'P'
when Vehicle is when Vehicle is
Stationary Stationary The vehicle is moving.
X
Stop the vehicle safely as soon as possible, paying attention to
road and traffic conditions.
X Shift the transmission to position P.A The tailgate is open.
G WARNING
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 tailgate. ? The hood is open.
G WARNING
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 188).
X Close the hood. C At least one door is open.
A warning tone also sounds.
X
Close all the doors. Display
messages
321On-board computer and displays Z

Display messages Possible causes/consequences and
M
MSolutions _
2nd 2nd
Seat
Seat Row,
Row,Left
Left
Not Locked
Not Locked or2nd
2nd
Seat Row, Right
Seat Row, Right
Not Locked Not Locked The second row of seats is not engaged on the left-hand or right-
hand side.
X
Fold back the second row of seats until it engages. _
3rd 3rd
Seat
Seat Row,
Row,Left
Left
Not Locked
Not Locked or3rd
3rd
Seat Row, Right
Seat Row, Right
Not Locked Not Locked The third row of seats is not engaged on the left-hand or right-hand
side.
X
Fold back the third row of seats until it engages. Ð
Power Steering Power Steering
Malfunction See Malfunction See
Owner's Manual Owner's Manual The power steering is malfunctioning.
A warning tone also sounds.
G WARNING
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. Phone No Service Phone No Service Your vehicle is outside the network provider's transmitter/
receiver range.
X
Wait until the mobile phone operational readiness symbol
appears in the multifunction display. ¥
Check Washer Fluid Check Washer Fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X
Add washer fluid ( Ypage 374). Wiper Wiper
Malfunctioning Malfunctioning The windshield wipers are malfunctioning.
X
Visit a qualified specialist workshop. Hazard Warning Hazard Warning
Flashers Flashers
Malfunctioning Malfunctioning The hazard warning lamps are faulty.
X
Visit a qualified specialist workshop. 322
Display
messagesOn-board computer and displays

Display messages Possible causes/consequences and
M
MSolutions Â
Key Not Detected Key Not Detected
(white display
message) The KEYLESS-GO key cannot be detected at present.
X
Change the location of the SmartKey with the KEYLESS-GO
functions in the vehicle.
If the KEYLESS-GO key is still not detected:
X Operate the vehicle with the SmartKey in the ignition lock. Â
Remove 'Start' Remove 'Start'
Button and Insert Button and Insert
Key Key KEYLESS-GO is temporarily malfunctioning or is defective. A
warning tone also sounds.
X
Insert the SmartKey into the ignition lock and turn it to the
desired position.
X Visit a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
Safety
Seat belts Problem Possible causes/consequences and
M MSolutions ü
After starting the
engine, the red seat
belt warning lamp lights
up for 6 seconds.
The seat belt warning lamp reminds the driver and front passenger
to fasten their seat belts.
X
Fasten your seat belt (Y page 57).ü
After starting the
engine, the red seat
belt warning lamp lights
up. In addition, a
warning tone sounds
for up to 6 seconds.
The driver's seat belt is not fastened.
X
Fasten your seat belt (Y page 57).
The warning tone ceases. ü
The red seat belt
warning 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 (Y page 57).
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. 324
Wa
rning and indi cator lamps in the instrument clusterOn-board computer and displays

Safety systems
Problem Possible causes/consequences and
M
MSolutions $
(USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the engine is
running. A warning tone
also sounds. G
WARNING
The brake boosting effect is malfunctioning and the braking
characteristics 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 (Y page 188).
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. $
(USA only)
J (Canada only)
The red brake system
warning lamp comes on
while the engine is
running. A warning tone
also sounds. There is not enough brake fluid in the brake fluid reservoir.
G WARNING
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 (Y page 188).
X Do not add brake fluid. Adding more will not remedy the
malfunction.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. 326
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running.
ABS (Anti-lock Braking System) is deactivated due to a
malfunction. For this reason, BAS (Brake Assist), BAS PLUS,
ESP
®
(Electronic Stability Program), PRE-SAFE ®
, PRE-SAFE ®
Brake, COLLISION PREVENTION ASSIST, the HOLD function, hill
start assist, crosswind driving assistance and ESP ®
trailer
stabilization are also deactivated, for example.
ATTENTION ASSIST is 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
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
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
transmission, will not be available. Warning and indicator lamps in the instrument cluster
327On-board computer and displays Z

Problem Possible causes/consequences and
M
MSolutions !
The yellow ABS warning
lamp is lit while the
engine is running. A
warning tone also
sounds.
EBD is malfunctioning. Therefore, ABS, BAS, BAS PLUS, ESP
®
,
PRE-SAFE ®
, PRE-SAFE ®
Brake, COLLISION PREVENTION ASSIST,
the HOLD function, hill start assist, crosswind driving assistance
and ESP ®
trailer stabilization, for example, are also not available.
ATTENTION ASSIST is deactivated.
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
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. $
(USA only)
J (Canada only)
֌!
The red brake warning
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. For this reason, BAS, BAS
PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, COLLISION PREVENTION
ASSIST, the HOLD function, hill start assist, crosswind driving
assistance and ESP ®
trailer stabilization, for example, are also not
available.
ATTENTION ASSIST is deactivated.
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
affected. The braking distance in an emergency braking situation
can increase.
If ESP ®
is not operational, ESP ®
is unable to stabilize the vehicle.
There is an increased risk of skidding and an accident.
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
329On-board computer and displays Z

Problem Possible causes/consequences and
M
MSolutions ÷
The yellow ESP
®
warning 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 When pulling away, only depress the accelerator pedal as far as
necessary.
X Ease off the accelerator pedal while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
In rare cases (Y page 72), it may be best to deactivate ESP ®
. 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 stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Reactivate ESP ®
.
In rare cases (Y page 72), it may be best to deactivate ESP ®
.
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, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, COLLISION
PREVENTION ASSIST, the HOLD function, hill start assist,
crosswind driving assistance and ESP ®
trailer stabilization are not
available due to a malfunction.
ATTENTION ASSIST is deactivated.
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 stabilize the vehicle.
There is an increased risk of skidding and an accident.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Visit a qualified specialist workshop. 330
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M
MSolutions F
(USA only)
! (Canada only)
The red electric parking
brake indicator lamp
flashes or lights up
and/or
!
warning lamp for the
electric parking brake
lights up. X
Observe the additional display messages in the multifunction
display. 6
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint
System).
G WARNING
The air bags or Emergency Tensioning Devices may either be
triggered unintentionally or, in the event of an accident, may not
be triggered.
There is an increased risk of injury.
X Observe the additional display messages in the multifunction
display.
X Drive on carefully.
X Have SRS checked at a qualified specialist workshop
immediately.
For further information about SRS, see (Y page 43).332
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Engine
Problem Possible causes/consequences and
M
MSolutions ;
The yellow Check
Engine warning lamp
lights up while the
engine is running.
There may be a malfunction, 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 gasoline engines)
R in the fuel system
The emission limit values may be exceeded and the engine may
be in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop.
i In some states, you must immediately visit a qualified
specialist workshop as soon as the yellow Check Engine warning
lamp lights up. This is due to the legal requirements in effect in
these states. If in doubt, check whether such legal regulations
apply in the state in which you are currently driving. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 185).
X Start the engine three to four times after refueling.
If the yellow Check Engine warning lamp goes out, emergency
running mode is canceled. The vehicle need not be checked. 8
The yellow reserve fuel
warning lamp lights up
while the engine is
running.
The fuel level has dropped into the reserve range.
X
Refuel at the nearest gas station. 8
The yellow reserve fuel
warning lamp flashes
while the vehicle is in
motion.
In addition, the
;
Check Engine warning
lamp may light up. 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. Warning and indicator lamps in the instrument cluster
333On-board computer and displays Z