2018 MERCEDES-BENZ C-CLASS CABRIOLET engine

Display messagesPossible causes/consequences andMSolutions
TrafficSignAssistCurrently Unavaila‐ble See Operator' sManual
Traffic SignAssis tis temporarily inoperative.
Possibl ecauses are:
RThe windshield in th ecamera' sfield of vision is dirty.
RVisibilit yis impaire ddue to heav yrain ,snow or fog .
XClean thewindshield.
If th esystem detects that th ecamera is full yoperational, th edisplay
message disappears.
Traffic Sig nAssis tis operational again .
TrafficSignAssistInoperativeTraffic Sig nAssis tis malfunctioning .
XVisitaqualified specialist workshop .
ë
Off
The HOLD function is deactivated. The vehicl eis skidding.
A warning tone also sounds.
XReactivat eth eHOLD function later (Ypage 162).
The HOLD function is deactivated. Whe nth ebrak epedal is firmly
depressed, an activation condition is no tfulfilled .
A warning tone also sounds.
XChec kth eactivation condition sfor th eHOLD function
(Ypage 161).
Distance Pilot OffDistanc ePilo tDISTRONI Cis deactivated (Ypage 158).
If it was no tdeactivated by th edriver , awarning tone also sounds.
Distance Pilot NowAvailableDistanc ePilo tDISTRONI Cis operational again after having been tem-
porarily unavailable .You can no wreactivat eDistanc ePilo t
DISTRONI C (
Ypage 155).
Distance Pilot Cur ‐rently UnavailableSee Operator'sMan ‐ual
Distanc ePilo tDISTRONI Cis temporarily inoperative.
Steering Pilo tis also temporarily inoperative.
Possibl ecauses are:
RThe radar sensor system is temporarily inoperative, e.g. due to
electromagneti cradiation emitted by nearby TV or radi ostation sor
other source sof electromagneti cradiation .
RThe system is outside th eoperating temperature range.
RThe on-boar dvoltag eis to olow.
A warning tone also sounds.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
Distanc ePilo tDISTRONI Cis operational again .
If th edisplay message does no tdisappear :
XPull overand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 143).
XRestart th eengine.
Display messages23 1
On-board computer and displays
Z

Display messagesPossible causes/consequences andMSolutions
TirePressure Moni‐tor Inoperative NoWheel Sensor s
The wheels mounte ddo no thav e a suitable tire pressur esensor .The
tire pressur emonitor is deactivated.
XMoun twheels wit hsuitable tire pressur esensors.
The tire pressur emonitor is activated automatically after drivin gfor
a few minutes.
Tir ePress.Monito rInoperativeThe tire pressur emonitor is faulty.
XVisit aqualified specialist workshop .
Tires OverheatedThe tire temperature monitoring function is no tavailable in all vehi-
cles.
At least on etire has overheated. Affecte dtires are shown in red .At
temperatures close to th elimi tvalue ,th etires are shown in yellow .
XDrive moreslowly.
Tires Overheate dDecrease SpeedThe tire temperature monitoring function is no tavailable in all vehi-
cles.
At least on etire has overheated.
GWARNIN G
Overheated tires can burst, particularly at high speeds .
XDrive moreslowly so that th etires cool down .
Vehicle
Display messagesPossible causes/consequences and MSolutions
Shiftto'P'or'N'to Start EngineYou haveattempte dto start th eengin ewit hth etransmission in posi-
tion korh.
XShift th etransmission to position jori .
Apply Brake toShift fro m'P'You hav eattempte dto shift th etransmission to position h,kori
without depressing th ebrak epedal .
XDepress th ebrak epedal .
ToDeselectPorN,Depres sBrake andStart Engine
Wit hth eengin eswitched off ,you hav eattempte dto shift th etrans -
mission out of position jori intoanother transmission position .
XDepress thebrak epedal .
XStart th eengine.
To Engage Trans‐miss. Position RFirst DepresstheBrake
You hav eattempte dto shift from position hto position k.
XDepress thebrak epedal .
XShift th etransmission to position k.
236Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
StopVehicl eLeaveEngineRunnin gWaitTransmission Cool‐ing
The transmission has overheated. Pullin gaway can be temporarily
impaire dor no tpossible.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions. Do no tcontinu edrivin g
under any circumstances.
XLeav eth eengin erunning.
XWait until th edisplay message disappear sbefore pullin gaway.
NThe trunk lid is open .
XCloseth etrunk lid.
MThe hoo dis open . Awarning tone also sounds.
GWARNIN G
The open hoo dmay bloc kyour vie wwhen th evehicl eis in motion .
There is aris kof an accident.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 143).
XCloseth ehood.
CAt least on edoor is open . Awarning tone also sounds.
XClos eall th edoors.
_
Front Lef tSea tBackrestNotLockedorFront Right Sea tBackrest Not Locked
The driver's or fron tpassenger's seat backrest is no tengaged. A
warning tone also sounds.
XPush th ebackrest bac kuntil it engages.
Ð
Power Steering Mal ‐function See Opera‐tor's Manual
The powersteering is malfunctioning .
A warning tone also sounds.
GWARNIN G
You will need to use mor eforce to steer .
There is aris kof an accident.
XChec kwhether you are able to apply th eextr aforce required.
If you ar eabl eto steer safely:
XDrive on carefully.
XVisit aqualified specialist workshop immediately.
If you ar eunable to steer safely:
XDo no tdrive on .
XConsult aqualified specialist workshop .
238Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Phone No ServiceYour vehicleis outside th enetwork provider' stransmitter/receiver
range.
XWait until th emobile phone operational readiness symbol appear s
in th emultifunction display.
J
TrunkPartitionOpe n
The trunk partition is open .
XCloseth etrunk partition (Ypage 90).
K
While stationary,apply the brakesbefore operatingthe softtop .
The vehicl eis stationary and you tr yto open or close th esof ttop.
XDepress th ebrak epedal .
XPush or pull th esof tto pswitch again until th esof tto pis full yopen
or closed (Ypage 89).
K
Convertible TopOperation Possibleto 35 mph
If you drive at speeds of mor ethan 35 mph (60 km/h), you canno t
open or close th esof ttop.
XDo no tdrive at speeds abov e35 mph (60 km/h).
XFull yopen or close th esof tto p (Ypage 89) .
K
ConvertibleTopLow‐ering
The sof tto pis no tfully opened or closed .The hydraulic sare depres-
surized.
XFull yopen or close th esof tto p (Ypage 89).
K
Open/Clos eConver ‐tibleTopCompletel y
The roofis no tlocked.
If you drive at speeds of mor ethan 35 mph (60 km/h), you canno t
open or close th esof ttop.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XPush or pull and hold th esoft-to pswitch until th esof tto pis full y
open or closed (Ypage 89).
K
Start Engine SeeOperator'sManual
The on-boar dvoltag eis to olow.
XStart th eengine.
¥
Check Washer Fluid
The washer flui dlevel in th ewasher flui dreservoir has dropped belo w
th eminimum .
XAddwasher flui d (Ypage 285).
Display messages239
On-board computer and displays
Z

SmartKey
Display messagesPossible causes/consequences andMSolutions
Â
KeyDoesNotBelongto Vehicle
You have put the wrong SmartKey in the ignition lock.
XUse the correct SmartKey.
Â
Take Your Key fromIgnition
The SmartKey is in the ignition lock.
A warning tone sounds
XRemove the SmartKey.
Â
Obtain a New Key
The SmartKey needs to be replaced.
XVisit a qualified specialist workshop.
Â
Replace Key Battery
The SmartKey battery is discharged.
XChange the batteries (Ypage 79).
Â
Don't Forget YourKey
The SmartKey is not in the ignition lock. You have opened the driver's
door with the engine switched off. A warning tone sounds
This display message is displayed for a maximum of 60 seconds and is
simply a reminder.
XTake the SmartKey with you when you leave the vehicle.
Â
Key Not Detected(white display message)
The SmartKey is currently undetected.
XChange the location of the SmartKey in the vehicle.
If the SmartKey still cannot be detected:
XInsert the SmartKey into the ignition lock and turn it to the desired position.
Â
Key Not Detected(red display message)
The SmartKey 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.
XPull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
XSecure the vehicle against rolling away (Ypage 143).
XLocate the SmartKey.
XPress aon the steering wheel to confirm the display message.
240Display messages
On-board computer and displays

Display messagesPossible causes/consequences andMSolutions
Becausethere is interferenc efrom astron gsource of radi owaves, th e
SmartKey is no tdetecte dwhils tth eengin eis running.
A warning tone also sounds.
XPull ove rand stop th evehicl esafely as soo nas possible, payin g
attention to roa dand traffic conditions.
XSecur eth evehicl eagainst rollin gaway (Ypage 143).
XInsertth eSmartKey int oth eignition loc kand drive in SmartKey
mode.
Â
Remove 'Start 'But ‐ton and Insert Key
The SmartKey is continually undetected.
The SmartKey detection function has atemporar ymalfunction or is
faulty. Awarning tone also sounds.
XInser tth eSmartKey int oth eignition loc kand tur nit to th edesire d
position .
XVisitaqualified specialist workshop .
Warning and indicat orlamps in the instrume nt cluster
General notes
Some systems carry out aself-diagnosis when th eignition is switched on .Therefore ,som eindicator
and warning lamp smay ligh tup or flas htemporarily. This behavio ris non-critical .These indicator
and warning lamp sonly indicat e amalfunction if they ligh tup or flas hafter starting th eengin eor
whils tdriving.
Safety
Seat belts
Warning/
indicator
lam pNSignal type
Possible causes/consequences and M
Solutions
üNAfte rstarting th eengine, th ered seat belt warning lamp lights up for six sec -
onds.
The seat belt warning lamp remind sth edriver and fron tpassenger to faste ntheir
seat belts.
XFaste nyour seat belt (Ypage 47).
üNAfte rstarting th eengine, th ered seat belt warning lamp lights up. In addition , a
warning tone sounds for up to six seconds.
The driver's seat belt is no tfastened.
XFaste nyour seat belt (Ypage 47).
The warning tone ceases .
Warning and indicator lamps in the instrument cluster241
On-board computer and displays
Z

Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
üNThe 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.
XFasten your seat belt (Ypage 47).
The warning lamp goes out.
There are objects on the front-passenger seat.
XRemove the objects from the front-passenger seat and stow them in a secure
place.
The warning lamp goes out.
üN The red seat belt warning lamp flashes and an intermittent audible warning
sounds.
The driver or front passenger has not fastened their seat belt. The vehicle is being driven faster than 15 mph (25 km/h) or has briefly been driven faster than 15 mph
(25 km/h).
XFasten your seat belt (Ypage 47).
The warning lamp goes out and the intermittent warning tone ceases.
There are objects on the front-passenger seat. The vehicle is being driven faster
than 15 mph (25 km/h) or has briefly been driven faster than 15 mph (25 km/h).
XRemove the objects from the front-passenger seat and stow them in a secure
place.
The warning lamp goes out and the intermittent warning tone ceases.
242Warning and indicator lamps in the instrument cluster
On-board computer and displays

Safety systems
Warning/
indicator
lampNSignal type
Possible causes/consequences and M
Solutions
$JN$ (USA only), J(Canada only): the red brake system warning lamp is lit
while the engine is running.
A warning tone also sounds.
GWARNING
The brake boosting effect is malfunctioning and the braking characteristics may be
affected.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 143).
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction display.
$JN $ (USA only), J(Canada only): the red brake system warning lamp lights
up while the engine is running.
A warning tone also sounds.
There is not enough brake fluid in the brake fluid reservoir.
GWARNING
The braking effect may be impaired.
There is a risk of an accident.
XPull over and stop the vehicle safely as soon as possible, paying attention to road
and traffic conditions. Do not continue driving under any circumstances.
XSecure the vehicle against rolling away (Ypage 143).
XDo not add brake fluid. Adding more will not correct the malfunction.
XConsult a qualified specialist workshop.
XObserve the additional display messages in the multifunction display.
$N USA only: the red brake system warning lamp is lit while the engine is running.
The multifunction display also shows a display message with the #symbol.
The brake pads/linings have reached their wear limit.
XVisit a qualified specialist workshop.
Warning and indicator lamps in the instrument cluster243
On-board computer and displays
Z