2016 MERCEDES-BENZ C-CLASS CABRIOLET ECU

Display messages
Possible causes/consequences and
M
MSolutions DTR+: steering
DTR+: steering
assist. currently assist. currently
unavailable unavailable
See
SeeOwn‐
Own‐
er's Manual
er's Manual Steering Assist and Stop&Go Pilot are temporarily inoperative.
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
R There are no lane markings for an extended period
R The lane markings are worn, dark or covered, e.g. by dirt or snow
Once the causes listed above no longer apply, the display message
disappears.
Steering Assist and Stop&Go Pilot are operational again.
If the display message does not disappear:
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 159).
X Clean the windscreen. DTR+: steering DTR+: steering
assistant inopera‐ assistant inopera‐
tive tive Steering Assist and Stop&Go Pilot are faulty.
However, the DISTRONIC PLUS functions are still available.
A warning tone also sounds.
X Consult a qualified specialist workshop. Cruise control and Cruise control and
SPEEDTRONIC inoper‐ SPEEDTRONIC inoper‐
ative ative SPEEDTRONIC and cruise control are faulty.
A warning tone also sounds.
X Consult a qualified specialist workshop. Speed Speed
limit
limit(winter
(winter
tyres) XXX mph
tyres) XXX mph You have reached the stored speed limit for winter tyres. It is not
possible to exceed this speed. You can suppress the display message
by pressing the abutton. The display message will not reappear
until the ignition has been switched on again. SPEEDTRONIC suspen‐ SPEEDTRONIC suspen‐
ded ded When you depress the accelerator pedal beyond the pressure point
(kickdown), SPEEDTRONIC is switched to passive mode.
The speed limitation is not active.
X Drive more slowly than the stored speed without kickdown.
or X Set a new speed.
or X Call up the last speed stored again.
When the display message disappears, the speed limitation is active. SPEEDTRONIC Limit SPEEDTRONIC Limit
- - - mph - - - mph SPEEDTRONIC cannot be activated, as not all the activation conditions
have been met.
X Check the activation conditions for SPEEDTRONIC (Y page 169). Display
messages
263On-board computer and displays Z

Tyres
Display messages
Possible causes/consequences and
M
MSolutions Tyre
Tyre
pressure
pressure Check
Check
tyres
tyres The tyre pressure loss warning system has detected a significant loss
in pressure.
A warning tone also sounds.
Possible causes:
R you have changed the positions of the wheels and tyres or fitted new
wheels and tyres
R the tyre pressure in one or more tyres has dropped
G WARNING
Underinflated tyres pose the following risks:
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 159).
X Check the tyres and, if necessary, follow the instructions for a flat
tyre (Y page 326).
X Check the tyre pressures and, if necessary, correct the tyre pres-
sure.
X Restart the tyre pressure loss warning system when the tyre pres-
sure is correct (Y page 347). Check tyre pres‐ Check tyre pres‐
sures then restart sures then restart
Run Flat Indicator Run Flat Indicator The tyre pressure loss warning system generated a display message
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 347).Run Flat Indicator Run Flat Indicator
inoperative inoperative The tyre pressure loss warning system is faulty.
X Consult a qualified specialist workshop. Rectify tyre pres‐
Rectify tyre pres‐
sure sure The tyre pressure is too low in at least one of the tyres, or the tyre
pressure difference between the wheels is too great.
X Check the tyre pressures at the next opportunity (Y page 348).
X If necessary, correct the tyre pressure.
X Restart the tyre pressure monitor (Y page 349). Display
messages
265On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Check tyre(s)
Check tyre(s) The tyre pressure in one or more tyres has dropped significantly. The
wheel position is displayed on the multifunction display.
A warning tone also sounds.
G WARNING
Underinflated tyres pose the following risks:
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 159).
X Check the tyres and, if necessary, follow the instructions for a flat
tyre (Y page 326).
X Check the tyre pressure (Y page 348).
X If necessary, correct the tyre pressure. Warning tyre defect Warning tyre defect The tyre pressure in one or more tyres has dropped suddenly. The
wheel position is displayed on the multifunction display.
G WARNING
If you drive with a flat tyre, there is a risk of the following hazards: R a flat tyre affects the ability to steer or brake the vehicle
R you could lose control of the vehicle
R continued driving with a flat tyre 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
manoeuvres. Pay attention to the traffic conditions as you do so.
X Secure the vehicle against rolling away (Y page 159).
X Check the tyres and, if necessary, follow the instructions for a flat
tyre (Y page 326). Tyre Tyre
press.
press. monitor
monitor
currently unavaila‐
currently unavaila‐
ble ble No signals can be received from the tyre pressure sensors due to
strong RF interference. The tyre pressure monitor is temporarily mal-
functioning.
X Drive on.
The tyre pressure monitor restarts automatically as soon as the
cause has been rectified. 266
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Wheel sensor(s)
Wheel sensor(s)
missing missing There is no signal from the tyre pressure sensor of one or several
wheels. The pressure of the affected tyre is not displayed on the mul-
tifunction display.
X
Have the faulty tyre pressure sensor replaced at a qualified spe-
cialist workshop. Tyre Tyre
press.
press. monitor
monitor
inoperative No
inoperative No
wheel sensors wheel sensors The wheels fitted do not have suitable tyre pressure sensors. The tyre
pressure monitor is deactivated.
X Fit wheels with suitable tyre pressure sensors.
The tyre pressure monitor is activated automatically after driving for
a few minutes. Tyre Tyre
press.
press. monitor
monitor
inoperative
inoperative The tyre pressure monitor is faulty.
X Consult a qualified specialist workshop. Vehicle
Display messages
Possible causes/consequences and
M
MSolutions To start engine,
To start engine,
shift to either P shift to either P
or N or N You have attempted to start the engine with the transmission in posi-
tion Ror D.
X Shift the transmission to position Por N. Apply
Apply
brake
braketo
todese‐
dese‐
lect Park (P) posi‐
lect Park (P) posi‐
tion tion You have attempted to shift the transmission to position
D,Ror N
without depressing the brake pedal.
X Depress the brake pedal. To shift out of P
To shift out of P
or or
N,
N,depress
depress brake
brake
and start engine
and start engine With the engine switched off, you have attempted to shift the trans-
mission out of position Por Ninto another transmission position.
X Depress the brake pedal.
X Start the engine. Risk of vehicle
Risk of vehicle
rolling Transmis‐ rolling Transmis‐
sion not in P sion not in P The driver's door is open or not fully closed and the transmission is in
position R,Nor D.
A warning tone also sounds.
G WARNING
The vehicle may roll away.
There is a risk of an accident.
X Shift the transmission to position P.
X Secure the vehicle against rolling away (Y page 159).
X Close the driver's door fully. Only select Park
Only select Park
(P) (P)
when
when vehicle
vehicle is
is
stationary
stationary The vehicle is moving.
X
Stop the vehicle, paying attention to road and traffic conditions.
X Shift the transmission to position P. Display
messages
267On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Without changing
Without changing
gear, consult work‐ gear, consult work‐
shop shop 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 trans-
mission from position D.
If transmission position R,Nor Pis selected:
X Secure the vehicle against rolling away (Y page 159).
X Consult a qualified specialist workshop. Reversing Reversing
not
not poss.
poss.
Consult workshop
Consult workshop You can no longer shift to transmission position
Rdue to a malfunc-
tion.
The transmission positions P,Nor Dcontinue to be available.
A warning tone also sounds.
X Consult a qualified specialist workshop. Transmission Mal‐ Transmission Mal‐
function Stop function Stop A malfunction has occurred in the mechanical transmission compo-
nents.
A warning tone also sounds. The transmission shifts automatically to position N.
X Stop the vehicle, paying attention to road and traffic conditions.
X Shift the transmission to position P.
X Secure the vehicle against rolling away (Y page 159).
X Consult a qualified specialist workshop. Stop vehicle Leave Stop vehicle Leave
engine engine
running
running Wait
Wait
Transmission cool‐
Transmission cool‐
ing ing The transmission has overheated. Pulling away can be temporarily
impaired or not possible.
X Stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving.
X Leave the engine running.
X Wait until the display message disappears before pulling away. Depress clutch
Depress clutch
fully to start fully to start
engine engine You have attempted to start the engine without depressing the clutch
pedal.
X Depress the clutch pedal.
X Restart the engine. The engine has stalled while pulling away, e.g. because the clutch
pedal was released too quickly.
X Depress the clutch pedal again.
The engine starts automatically.
X Slowly release the clutch pedal to pull away. 268
Display
messagesOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions Clutch overheated
Clutch overheated
Avoid pulling away Avoid pulling away
Engage/disengage Engage/disengage
clutch quickly if clutch quickly if
req. req. The clutch is under considerable load and the permitted operating
temperature has been exceeded. A warning tone also sounds.
Avoid frequent pulling away and driving at walking pace over longer
distances.
X Stop the vehicle, paying attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 159).
X Leave the engine running.
The clutch is cooled more quickly with the engine running.
or X If possible, drive on at a steady speed.
X Remove your foot from the clutch pedal and do not allow the clutch
to slip.
The clutch may also cool down during the journey.
It may take several minutes for it to cool down. When the clutch has
cooled down, the display message disappears. The clutch is fully
operational again. N The boot lid is open.
X Close the boot lid. M The bonnet is open. A warning tone also sounds.
G WARNING
The open bonnet may then block your view when the vehicle is in
motion.
There is a risk of an accident.
X Stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions.
X Secure the vehicle against rolling away (Y page 159).
X Close the bonnet. Active bonnet mal‐ Active bonnet mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The active bonnet (pedestrian protection) is not active due to a mal-
function or because it has already been triggered.
X Consult a qualified specialist workshop. C At least one door is open. A warning tone also sounds.
X Close all doors. _
Front left seat Front left seat
backrest backrest
not
notlocked
locked
or Front right seat
Front right seat
backrest not locked
backrest not locked The driver's or front-passenger's seat backrest is not engaged. A
warning tone also sounds.
X Push the backrest back until it engages. Display
messages
269On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions j
Check Check
trailer
trailer hitch
hitch
lock
lock The trailer tow hitch is not correctly engaged.
A warning tone also sounds.
G WARNING
If the ball coupling is not engaged, the trailer may come loose. There
is a risk of an accident.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Secure the vehicle against rolling away (Y page 159).
X Engage the ball coupling of the trailer tow hitch in the end position
(Y page 214). Ð
Power steering mal‐ Power steering mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The power steering assistance is faulty.
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 steering force
required.
If you are able to steer safely:
X Drive on carefully.
X Consult a qualified specialist workshop immediately.
If you are unable to steer safely:
X Do not drive on.
X Consult a qualified specialist workshop. Ð
Steering malfunc‐ Steering malfunc‐
tion See Owner's tion See Owner's
Manual Manual Vehicles with manual transmission:
The electric steering lock is malfunctioning.
G WARNING
The steering may be locked by the electric steering lock.
There is a risk of an accident.
X Stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions.
X Secure the vehicle against rolling away (Y page 159).
X Do not drive on.
X Consult a qualified specialist workshop. _
Before Before
starting
starting the
the
engine, turn the
engine, turn the
steering wheel. steering wheel. Vehicles with manual transmission:
The electric steering lock is malfunctioning.
X Remove the key from the ignition lock.
X To unlock the steering, move the steering wheel slightly.
X Insert the key into the ignition lock again. 270
Display
messagesOn-board computer and displays

Key
Display messages
Possible causes/consequences and
M
MSolutions Â
Key Key
does
does not
notbelong
belong
to vehicle
to vehicle You have put the wrong key in the ignition lock.
X Use the correct key. Â
Replace key Replace key The key needs to be replaced.
X Consult a qualified specialist workshop. Â
Change Change
key
keybatteries
batteries The key battery is discharged.
X Replace the batteries (Y page 84).Â
Key not detected Key not detected
(white display message) The key is currently undetected.
X Change the location of the key in the vehicle.
If the key still cannot be detected:
X Insert the key into the ignition lock and turn it to the desired posi-
tion. Â
Key not detected Key not detected
(red display message) The key is not in the vehicle.
A warning tone also sounds.
If the engine is switched off, you can no longer lock the vehicle cen-
trally or start the engine.
X Stop the vehicle immediately, paying attention to road and traffic
conditions.
X Secure the vehicle against rolling (Y page 159).
X Locate the key.
X Press aon the steering wheel to confirm the display message. Because there is interference from a strong source of radio waves, the
key is not detected whilst the engine is running.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traffic
conditions.
X Secure the vehicle against rolling (Y page 159).
X Insert the key into the ignition lock and bring into key mode. Â
Remove Remove
starting
starting but‐
but‐
ton,
ton, then
theninsert
insert key
key The key is continually undetected.
The key detection function has a temporary malfunction or is faulty. A
warning tone also sounds.
X Insert the key into the ignition lock and turn it to the desired posi-
tion.
X Consult a qualified specialist workshop. 272
Display
messagesOn-board computer and displays