Display messages Possible causes/consequences and
M Solutions
J
Check brake fluid
level There is insufficien
tbrake fluid in the brake flui dreservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
G WARNING
The braking efficiency 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 .Donot continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 177).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake pad
wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. PRE-SAFE
inoperative See
Owner's Manual Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
Functions cur‐
rently limited See
Owner's Manual PRE-SAFE
®
Brake is temporarily inoperative. Possible causes:
R the function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and in the bumpers are dirty.
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.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
PRE-SAFE ®
Brake is operational again.
If 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 Secure the vehicle against rolling away (Y page 177).
X Clean the sensors in the radiator trim and in the bumpers
(Y page 317).
X Restart the engine. Display messages
253On-board computer and displays Z
Display messages Possible causes/consequences and
M Solutions
b
Switch off lights The lights are still switched on when you leave the vehicle. A
warning tone also sounds.
X Tur nthe 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. Engine
Display messages Possible causes/consequences and
M Solutions
+
Top
up coolant See
Owner's Manual The coolant level is too low.
!
Avoid making long journeys with too little coolant in the engine
cooling system. The engine will otherwise be damaged.
X Top up the coolant, observing the warning notes before doing
so (Y page 310).
X If the coolant needs topping up more often than usual, have the
engine coolant system checked at a qualified specialist work-
shop. ? The fan motor is faulty.
X
If the coolant temperature is below 120 †, you can continue
driving to the nearest qualified specialist workshop.
X Avoid heavy loads on the engine as you do so, e.g. driving in
mountainous terrain and stop-start traffic. Display messages
259On-board computer and displays Z
Display messages Possible causes/consequences and
M Solutions
?
Coolant Stop vehi‐
cle Switch engine
off The coolan
tis too hot.
Aw arning tone also sounds.
G WARNING
Never drive with an overheated engine. Driving when your engine
is overheated can cause som efluids which may have leaked into
the engine compartment to catch fire.
Steam fro manoverheated engine can cause serious burns, which
can occur just by opening the bonnet.
This poses a risk of injury.
X Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 177).
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 frozen slush.
X Do not start the engine again until the display message goes out
and the coolant temperature is under 120 †. The engine may
otherwise be damaged.
X Pay attention to the coolant temperature display.
X If the temperature increases again, visi taqualified specialist
workshop immediately.
The reading may rise up to 120 †undernormal driving conditions
if the coolant has been filled correctly. 260
Display messagesOn-board computer and displays
Display messages Possible causes/consequences and
M Solutions
Blind Spot Assis
torActive Blind Spot Assist is temporarily inop-
erative .Possible causes:
R the sensors are dirty.
R the 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.
Once the causes listed above no longer apply, the display message
goes out.
Blind Spot Assist or Active Blind Spot Assist is operational again.
If 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 Secure the vehicle against rolling away (Y page 177).
X Clean the sensors (Y page 317).
X Restart the engine. Blind Spot Assist
inoperative or
Active Blind Spot Assist inoperative 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 203).
X Restart the engine.
If the display message continues to be displayed:
X Visit a qualified specialist workshop. Display messages
265On-board computer and displays Z
Display messages Possible causes/consequences and
M Solutions
DISTRONIC PLUS cur‐
rently unavailable
See Owner's Manual DISTRONIC PLU
Sis temporarily inoperative. Possible causes:
R the function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and in the bumpers are dirty.
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.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Aw arning tone also sounds.
Once the causes listed abov eno longer apply, the display message
goes out.
DISTRONIC is operational again.
If 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 Secure the vehicle against rolling away (Y page 177).
X Clean the sensors in the radiator trim and in the bumpers
(Y page 317).
X Restart the engine. DISTRONIC PLUS
inoperative DISTRONIC PLUS is faulty.
BAS PLUS and PRE-SAFE
®
Brake may also have failed.
Aw arning tone also sounds.
X Visi taqualified specialist workshop. DISTRONIC PLUS
inactive You have depressed the accelerator pedal. DISTRONIC PLUS is no
longer controlling the speed of the vehicle.
X
Remove your foot from the accelerator pedal. DISTRONIC PLUS
--- km/h An activation condition for DISTRONIC PLUS is not fulfilled.
X
Check the activation conditions for DISTRONIC PLUS
(Y page 188). DISTRONIC PLUS and
SPEEDTRONIC DISTRONIC PLUS and SPEEDTRONIC are faulty. A warning tone
also sounds.
X Visit a qualified specialist workshop. Cruise control and
SPEEDTRONIC inop‐
erative SPEEDTRONIC and cruise control are malfunctioning.
Aw arning tone also sounds.
X Visi taqualified specialist workshop. Display messages
267On-board computer and displays Z
Tyres
Display messages Possible causes/consequences and
M Solutions
Tyre pressure
Check tyres The tyre pressure loss warning system has detected a significant
loss in pressure.
Aw
arning tone also sounds.
G WARNING
With tyre pressures which are too low, there is a ris kofthe fol-
lowing hazards:
R the tyres may burst, especially as the load and vehicle speed
increase.
R the tyres may wear excessively and/or unevenly, which may
greatly impair tyre 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
manoeuvres. Pay attention to the traffic conditions as you do
so.
X Secure the vehicle against rolling away (Y page 177).
X If there is a flat tyre, inspect the tyres (Y page 324).
X Check the tyre pressures and, if necessary, correct the tyre
pressure.
X Restart the tyre pressure loss warning system when the tyre
pressure is correct (Y page 345).Check tyre pres‐
sures
then restart Run
Flat Indicator The tyre pressure loss warning system generated a displaym
es-
sage and has not been restarted since.
X Set the correct tyre pressure in all four tyres.
X Restart the tyre pressure loss warning system (Y page 345).Run Flat Indicator
inoperative The tyre pressure loss warning system is faulty.
X
Visit a qualified specialist workshop. Display messages
269On-board computer and displays Z
Vehicle
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. While the HOLD functio
norDISTRONIC PLUS is active, you have:
R opened the driver's door and released the seat belt or
R switched off the engine or
R opened the bonnet
At one may also sound at regular intervals. If you attempt to lock
the vehicle, the tone becomes louder.
You cannot start the engine.
X Shift the transmission to position P.
You can restart the engine. Without changing
gear,
consult workshop You cannot change the transmission position due to a malfunction.
Aw
arning 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 Consult a qualified specialist workshop. N The boot lid is open.
X
Close the boot lid. 270
Display messagesOn-board computer and displays
Display messages Possible causes/consequences and
M Solutions
Telephone 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. K
Convertible Top
Operation possible
to 40 km/h If you drive at speeds of more than 40 km/h, you canno
topen or
close the soft top.
X Fully open or close the soft top (Y page 93).K
Top lowering The soft top is not fully opened or closed. The hydraulics are dep-
ressurised.
X
Fully open or close the soft top (Y page 93).K
Open/close
top com‐
pletely The soft top is not locked.
If you drive at speeds of more than 40 km/
h,you canno topen or
close the soft top.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Push or pull the soft-top switch until the soft top is fully open or
closed (Y page 93). K
Start Engine See
Owner's Manual The on-board voltage is too low.
X
Start the engine. The soft top has been opened and closed several times in a row.
The soft-top drive has been switched off automatically for safety
reasons.
You can open and close the soft top again after approximately ten
minutes.
X
Switch off the ignition and turn it back on.
X Repeat the opening or closin gprocedure (Y page 93). ¥
Top
up washer fluid The washer fluid level in the washer fluid reservoi
rhas dropped
below the minimum.
X Top up the washe rfluid (Y page 310). Display messages
273On-board computer and displays Z