Display messages Possible causes/consequences and
M Solutions
b
Trailer brake lamp The trailer brake lamp is faulty.
X
Chec kwhether you are permitted to change the bulb yourself.
or
X Visit a qualified specialist workshop. b
Rear
left indicator
or
Rear right indi‐ cator The rear left-hand or rear right-hand turn signal 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 indica‐
tor or
Front right indicator The front left-hand or front right-hand turn signal 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
mirror indica‐
tor or
Right mir‐ ror indicator The turn signal in the left-hand or right-hand exterior mirror is
faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Third brake lamp The third brake 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
Tail/brake lamp,
left or
Tail/brake lamp, right The left or right-hand tail lamp/brake 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 main beam
or
Right main beam The left or right-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. 262
Display messagesOn-board computer and displays
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
Trailer left indi‐
cator or
Trailer right indicator The lef
torright-hand trailer tur nsignal lamp is faulty.
X Check whether you are permitted to change the bulb yourself.
or
X Visit a qualified specialist workshop. b
Trailer brake lamp The trailer brake lamp is faulty.
X Check whether you are permitted to change the bulb yourself.
or
X Visit a qualified specialist workshop. b
Rear
left indicator
or
Rear right indi‐ cator The rear left-hand or rear right-hand tur
nsignal 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 indica‐
tor or
Front right indicator The front left-hand or front right-hand turn signal 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
mirror indica‐
tor or
Right mir‐ ror indicator The turn signal in the left-hand or right-hand exterior mirror is
faulty.
X Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. b
Third brake lamp The third brake 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-hand tail
lamp/brake lamp or
Right-hand tail lamp/brake lamp The left or right-hand tail lamp/brake lamp is faulty.
X
Check whether you are permitted to change the bulb yourself
(Y page 125).
or
X Visit a qualified specialist workshop. Display messages
265On-board computer and displays Z
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
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
Display messages Possible causes/consequences and
M Solutions
Check trailer
hitch lock G
Risk of accident
Vehicles with a retractable trailer coupling:
The trailer tow hitch is no tcorrectly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 217). Pwr. steering
malfunc. G
Risk of accident
The power steering assistance is faulty. You will need to use more
force to steer.
Aw arning tone also sounds.
X Chec kwhether 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. Top up
washer fluid The washer fluid level in the washer fluid reservoir has dropped
below the minimum.
X
Top up the washer fluid (Y page 325).Vehicle (12-button multifunction steering wheel)
Display messages Possible causes/consequences and
M Solutions
To start engine,
shift to either P
or N You have attempted to start the engine with the transmission in
position
Ror D.
X Shift the transmission to position Por N. P
Select Park (P) You have switched off the engine with the Start/Stop button and
opened the driver's door.
You wanted to lock the vehicle.
Aw
arning tone also sounds.
or
You have switched off the engine with the Start/Stop butto nand
opened the driver's door with the transmission in position N.
X Shift the transmission to position P. Display messages
285On-board computer and displays Z
Display messages Possible causes/consequences and
M Solutions
j
Check trailer
hitch lock G
Risk of accident
The trailer tow hitch is no tcorrectly engaged.
Aw arning tone also sounds.
X Stop the vehicle immediately, paying attentio ntoroad and traf-
fic conditions, and switch off the engine.
X Apply the parking brake.
X Allow the trailer tow hitch ball coupling to engage in the end
position (Y page 217). D
Power
steering mal‐
function See Own‐
er's Manual G
Risk of accident
The power steering assistance is faulty.
You will need to use more force to steer.
Aw arning tone also sounds.
X Chec kwhether 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. &
inoperative Bat‐
tery low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 143).
X Drive for a longer distance.
The battery is being charged. The auxiliary heating is operational
again as soon as the on-board electrical system voltage is suf-
ficient. &
inoperative
Refuel
vehicle The fuel level in the fuel tank is too low. The auxiliary heating can-
not be switched on (Y page 143).
X Refuel at the nearest filling station. &
inoperative See
Owner's Manual The auxiliary heating has a temporary malfunction or is faulty.
X
When the vehicle is on alevel surface and the engine has cooled
down, make up to four attempts to switch on the auxiliary heat-
ing, waiting several minutes between each attempt
(Y page 143).
X If the auxiliary heating does not switch on, consult a qualified
specialist workshop. Display messages
287On-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