Display messages Possible causes/consequences and
M Solutions
b
Left fog lamp
or
Right fog lamp The left-hand or right-hand fron
tfoglamp is faulty.
X Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Rear fog lamp The rear foglamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Front
left parking
lamp or
Front right parking lamp The front left or front right parking lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Reversing light The reversing lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Rear left marker
lamp or
Rear right marker lamp The rear left or right side marker lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Left daytime driv‐
ing lamp
or
Right dayt. driv‐ ing lamp The left or right daytime driving lamp is defective.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Malfunction The exterior lighting is faulty.
X
Visit a qualified specialist workshop. Display messages
263On-board computer and displays Z
Display messages Possible causes/consequences and
M Solutions
Vehicles with trailer tow hitch
:afuse may have blown.
X Check the fuses (Y page 354).
X If necessary, replace the blown fuse .Observe the warning notes
as you do so.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. b
AUTO
lights inoper‐
ative The light senso
ris faulty.
X Visit a qualified specialist workshop. b
Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X
Turn the light switch to Ã.Lights (12-button multifunction steering wheel)
i Display messages aboutL EDs:
This display message will only appear if all LEDs have failed. Display messages Possible causes/consequences and
M Solutions
b
Left cornering
light or
Right cor‐ nering light The left or right-hand cornering ligh
tis faulty.
X Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Left dipped beam
or
Right dipped beam The left or right-hand dipped-beam headlamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Trailer left tail
lamp or
Trailer right tail lamp The left or right-hand trailer tail lamp is faulty.
X
Check whether you are permitted to change the bulb yourself.
or
X Visit a qualified specialist workshop. 264
Display messagesOn-board computer and displays
Display messages Possible causes/consequences and
M Solutions
b
Left main beam
or
Right main beam The lef
torright-hand high beam is faulty.
X Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Left fog lamp
or
Right fog lamp The left-hand or right-hand front foglamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Rear fog lamp The rear foglamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Front
left parking
lamp or
Front right parking lamp The front left or front right parking lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Reversing light The reversing lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Rear left side
marker lamp or
Rear right side marker lamp The rear left or right side marker lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Left daytime driv‐
ing lamp or
Right daytime driving
lamp The left or right-hand daytime driving lamp is defective.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. 266
Display messagesOn-board computer and displays
Display messages Possible causes/consequences and
M Solutions
b
Intell. Light Sys‐
tem inoperative The Intelligent Light Syste
mis faulty. The lights remain available
without the Intelligent Light System.
X Visit a qualified specialist workshop. b
Malfunction See
Owner's Manual The exterior lighting is faulty.
X
Visit a qualified specialist workshop. Vehicles with trailer tow hitch: a fuse may have blown.
X
Check the fuses (Y page 354).
X If necessary, replace the blown fuse. Observe the warning notes
as you do so.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. b
AUTO
lights inoper‐
ative The light sensor is faulty.
X
Visit a qualified specialist workshop. b
Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X
Turn the light switch to Ã.Adaptive Main-beam
Assist inoperative Adaptive Highbeam Assist is faulty.
X
Visit a qualified specialist workshop. Adaptive Main-beam
Assist currently
unavailable See
Owner's Manual Adaptive Highbeam Assist is deactivated and temporarily inoper-
ative. Possible causes:
R
the windscreen is dirty in the camera's field of vision.
R visibility is impaired due to heavy rain, snow or fog.
X Cleant he windscreen.
If the system detects that the camera is fully operational again,
the Adaptive Main-beam Assist available again message
is displayed.
Adaptive Highbeam Assist is operational again. Display messages
267On-board computer and displays Z
Display messages Possible causes/consequences and
M Solutions
The HOLD function is deactivated. If the brake pedal is firmly
depressed, an activation condition is no longer fulfilled.
Aw
arning tone also sounds.
X Check the activation conditions for the HOLD function
(Y page 193). Radar sensor deac‐
tivated autom. See
Owner's Manual Vehicles with a navigation system: the vehicle is close to a radio
telescope facility and is therefore prohibited from transmitting any
radar signals. The radar sensor system has switched off automat-
ically (Y
page 389).
DISTRONI CPLUS (Y page 183) is deactivated automatically if it is
activated. Awarning tone also sounds.
Blind Spo tAssist (Y page 205) or Active Blind Spot Assist
(Y page 209) is deactivated automatically if it is activated. The
yellow 9indicator lamps also light up in the exterior mirrors.
BAS PLUS (Brake Assist PLUS) (Y page 73) and PRE-SAFE®
Brake
(Y page 78) are then also not available.
X Drive on.
Once you have moved far enough away from the radio telescope,
the above functions are available again. Vehicles with Becker
®
MAP PILOT: if the Becker ®
MAP PILOT is
not connected, the radar sensor system is deactivated automati-
cally.
BAS PLUS, DISTRONIC PLUS, Blind Spot Assist or Active Blind
Spot Assist and PRE-SAFE ®
Brake are not available.
X Connect the Becker ®
MAP PILOT; see the separate operating
instructions. Radar sensor
deactivated See
Owner's Manual The radar sensor system is deactivated.
X
Check whether or not the radar sensor system may be activated
(Y page 389).
X Switch on the radar sensor system (Y page 242).274
Display messagesOn-board computer and displays
Display messages Possible causes/consequences and
M Solutions
Blind Spot Assist
currently unavail‐
able See Owner's
Manual orActive
Blind Spot Assist
currently unavail‐
able See Owner's
Manual Blind Spot Assis
torActive Blind Spot Assist is temporarily inop-
erative .Possible causes:
R you have established the electrical connection between the
trailer and your vehicle.
R the sensors are dirty.
R function is impaired due to heavy rain or snow.
R the radar sensor system is outside the operating temperature
range.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
The yellow 9indicator lamps also light up in the exterior mir-
rors.
X When towing a trailer, confirm the display message with a.
If you are driving without a trailer and the display message does
not disappear:
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Apply the parking brake.
X Clean the sensors (Y page 330).
X Restart the engine.
If the system detects that the sensors are fully operational, the
display message disappears.
Blind Spot Assist or Active Blind Spot Assist is operational again. Blind Spot Assist
inopera‐
tive orActive Blind
Spot Assist inoper‐
ative Blind Spot Assist or Active Blind Spot Assist is faulty.
The yellow
9indicator lamps also light up in the exterior mir-
rors.
X Visit a qualified specialist workshop. Parking Guidance
inoperative Parking Guidance is malfunctioning (Y
page 199).
X Restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. 276
Display messagesOn-board computer and displays
Warning and indicator lamps in the instrument cluster
Seat belts
Problem Possible causes/consequences and
M Solutions
7
Only for certain coun-
tries: the red sea
tbelt
warning lamp lights up
for six seconds after
the engine starts. The seat belt warning lamp reminds the driver and fron
tpassenger
to fasten their seat belts.
X Faste nyour seat belt (Y page 53). 7
Only for certain coun-
tries: the red seat belt
warning lamp lights up
after the engine starts.
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 53).
The warning tone ceases. 7
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.
G
Risk of injury
The driver or front passenger has not fastened their seat belt.
X Fasten your seat belt (Y page 53).
The warning lamp goes out. G
Risk of injury
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. Warning and indicator lamps in the instrument cluster
291On-board computer and displays Z
Safety systems
Problem Possible causes/consequences and
M Solutions
J
The red brake system
warning lamp comes on
while the engine is run-
ning. A warning tone
also sounds. G
Risk of accident
There is insufficient brake fluid in the 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 Apply the parking brake.
X Consult a qualified specialist workshop immediately.
X Observe the additional display messages in the multifunction
display.
Do not top up the brake fluid. This does not correct the error. !
The yellow ABS warning
lamp is lit while the
engine is running. G
Risk of accident
ABS (Anti-lock Brake System) has been deactivated due to a fault.
For this reason, BAS (Brake Assist), BAS PLUS, ESP ®
(Electronic
Stability Program), PRE-SAFE ®
,P RE-SAFE ®
Brake ,the HOLD func-
tion, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are 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.
ATTENTION ASSIST is deactivated.
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. Warning and indicator lamps in the instrument cluster
293On-board computer and displays Z