2018 MERCEDES-BENZ C-CLASS CABRIOLET check engine

ProblemPossible causes/consequences andMSolutions
The engine does not
start. The starter motor
can be heard. The
reserve fuel warning
lamp is lit and the fuel
gauge display is at the
reserve level.The fuel tank is empty.
XRefuel the vehicle.
The engine does not
start. You cannot hear
the starter motor.The on-board voltage is too low because the battery is too weak or
discharged.
XJump-start the vehicle (Ypage 304).
If the engine does not start despite attempts to jump-start it:
XConsult a qualified specialist workshop.
The starter motor was exposed to a thermal load that was too high.
XTry to start the engine again (Ypage 125).
If the engine still does not start:
XConsult a qualified specialist workshop.
The engine is not running
smoothly and is misfir-
ing.There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
XOnly depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic converter
and damage it.
XHave the cause rectified immediately at a qualified specialist work-
shop.
The coolant temperature
display is pointing to the
red mark.The coolant level is too low. The coolant is too hot and the engine is no
longer being cooled sufficiently.
XStop as soon as possible and allow the engine and the coolant to
cool down.
XCheck the coolant level (Ypage 284). Observe the warning notes
as you do so and add coolant if necessary.
DYNAMIC SELECT switch
Mercedes-AMG vehicles
General information
Use the DYNAMIC SELECT switch to select the
drive program. Available drive programs for Mercedes-
AMG C 43 4MATIC:
S+
Sport PlusParticularly sporty driving
characteristics
SSportSporty driving characteris-
tics
C ComfortComfortable and economi-
cal driving characteristics
EEconomyParticularly economical
driving characteristics
IIndividualIndividual settings
130DYNAMIC SELECT switch
Driving and parking

leave children or animals unattended in the
vehicle. Always keep the SmartKey out of
reach of children.
XIf the transmission is in positionhork:
push the DIRECT SELECT lever up or down to
the first point of resistance.
XIf the transmission is in position j: depress
the brake pedal and push the DIRECT SELECT
lever up or down to the first point of resist-
ance.
If you switch the engine off with the transmis-
sion in position korh, the automatic trans-
mission shifts to iautomatically.
With the SmartKey: if you then open the driv-
er's door or the front-passenger door or remove the SmartKey from the ignition lock, the auto-
matic transmission shifts to jautomatically.
With the Start/Stop button: if you then open
the driver's door or the front-passenger door,
the automatic transmission shifts to jauto-
matically.
If you want the automatic transmission to
remain in neutral i, e.g. when having the vehi-
cle cleaned in an automatic, tow-through car
wash:
XVehicles with KEYLESS-GO or KEYLESS-
GO start function: remove the Start/Stop
button from the ignition lock.
XInsert the SmartKey into the ignition lock.
XAll vehicles: switch the ignition on.
XDepress the brake pedal and keep it
depressed.
XEngage neutral i.
XRelease the brake pedal.
XRelease the electric parking brake.
XSwitch off the ignition and leave the SmartKey
in the ignition lock.
Engaging the drive position
XIf the transmission is in position kori:
push the DIRECT SELECT lever down past the first point of resistance.
XIf the transmission is in position j: depress
the brake pedal and push the DIRECT SELECT lever down past the first point of resistance.
Transmission position and drive pro-
gram display
The current transmission position and drive pro-
gram appear in the multifunction display.
:Status symbol drive program
;Transmission position
=Gear
The arrows in the transmission position display
show how and into which transmission positions
you can shift using the DIRECT SELECT lever.
If the transmission position display in the mul-
tifunction display is not working, you should pull
away carefully to check whether the desired
transmission position is engaged. Ideally, you
should select transmission position hand
drive program E(for Mercedes-AMG vehicles:
drive program C) orS.
134Automatic transmission
Driving and parking

Transmission positions
BPark position
This prevents the vehicle from rolling
away when stopped.
Only shift the transmission into posi-
tion j(
Ypage 133) when the vehi-
cle is stationary. The parking lock
should not be used as a brake when
parking. Always apply the electronic
parking brake in addition to the park-
ing lock in order to secure the vehi-
cle.
Park position jis automatically
engaged if:
Ryou switch off the engine using the SmartKey and remove the Smart-
Key
Ryou switch off the engine using theSmartKey or using the Start/Stop
button and open the driver's door
or front-passenger door
Ryou open the driver's door when
the vehicle is stationary or when
driving at a very low speed and thetransmission is in position hor
k
In the event of a malfunction of the
vehicle's electronics, the transmis-
sion may lock in position j. Have
the vehicle electronics checked
immediately at a qualified specialist
workshop.
CReverse gear
You can only shift the transmission
into position kwhen the vehicle is
stationary (
Ypage 133).
ANeutral
Do not shift the transmission to i
while driving. Otherwise, the auto-
matic transmission could be dam-
aged.
No power is transmitted from the
engine to the drive wheels.
Releasing the brake pedal will allow
you to move the vehicle freely, e.g. to
push it or tow it.
If ESP
®is deactivated or faulty: shift
the transmission to position iif the
vehicle is in danger of skidding, e.g.
on icy roads.
If you switch the engine off with the
transmission in position korh,
the automatic transmission shifts to
i automatically.
!Coasting in neutral imay
cause damage to the drive train.
7Drive
The automatic transmission changes
gear automatically. All forward gears
are available.
Driving tips
Changing gear
The automatic transmission shifts through the
individual gears automatically when it is in trans-
mission position h. This automatic gear shift-
ing behavior is determined by:
Rthe selected drive program
Rthe position of the accelerator pedal
Rthe road speed
Accelerator pedal position
Your style of driving influences how the auto-
matic transmission shifts gear:
Rlittle throttle: early upshifts
Rmore throttle: late upshifts
Double-clutch function
When shifting down, the double-clutch function
is active regardless of the currently selected
drive program. The double-clutch function
Automatic transmission135
Driving an d parking
Z

Kickdown
XFormaximum acceleration ,depress th e
accelerato rpedal beyon dth epressur epoint.
The automatic transmission shift sto alower
gear depending on th eengin espeed.
XShift bac kup once th edesire dspee dis
reached. If you apply full throttle, th
eautomatic trans -
mission shift sup to th enext gear when th e
maximum engin espeed is reached. This pre -
vents th eengin efrom overrevving .
Mercedes-AMG vehicles: kickdown is only
possibl ein th etemporar ysetting .
Problems with the trans mission
ProblemPossible causes/consequences and MSolutions
The transmission has
problemsshifting gear .The transmission is losing oil.
XHaveth etransmission checke dat aqualified specialist workshop
immediately.
The acceleration abilit y
is deteriorating .
The transmission no lon -
ger changes gear .The transmission is in emergenc ymode.
It is possibl eto shift to agear and revers egear only.
XStop th evehicle.
XShift th etransmission to position j.
XSwitchoff th eengine.
XWait at least te nseconds before restarting th eengine.
XShift th etransmission to position hork.
If h is selected, th etransmission only shift sto on egear ;if k is
selected, th etransmission shift sto revers egear .
XHaveth etransmission checke dat aqualified specialist workshop
immediately.
Transfer case
This section is only valid for vehicles wit h4-
whee ldrive (4MATIC). Powe ris always trans -
mitte dto bot haxles.
!Performance test smay only be carrie dout
on a2-axl edynamometer. The brak esystem
or transfer cas ecould otherwise be damaged.
Contac t aqualified specialist workshop for a
performance test .
!Since ESP®engagesautomatically, th eigni-
tion mus tbe switched off (the SmartKey or
Start/Sto pbutto nmus tbe in position gor
1) if
Rtheelectrical parking brak eis bein gtested
usin g adynamometer
Rthevehicl eis bein gtowed wit honly on e
axl eraised (not permitte dfor vehicles wit h
4MATIC) Otherwise
,th ebrak esystem can be dam-
aged .
!Vehicles wit h4MATIC mus tno tbe towed
wit heither th efron tor th erear axl eraised, as
doin gso will damag eth etransmission .
Refueling
Important safety notes
GWARNIN G
Fue lis highly flammable. If you handle fuel
incorrectly, there is aris kof fir eand explo-
sion .
You mus tavoid fire, open flames, creating
sparks and smoking .Switc hoff th eengin e
and ,if applicable, th eauxiliary heating before
refueling.
Refueling141
Driving and parking
Z

This helps you to avoid overheating the
brakes and wearing them out excessively.
When you take advantage of engine braking, a
drive wheel may not turn for some time, e.g.
on a slippery road surface. This could cause
damage to the drive train. This type of damage is not covered by the Mercedes-Benz war-
ranty.
Heavy and light loads
GWARNING
If you rest your foot on the brake pedal while
driving, the braking system can overheat. This increases the stopping distance and can even
cause the braking system to fail. There is a
risk of an accident.
Never use the brake pedal as a footrest. Never
depress the brake pedal and the accelerator
pedal at the same time.
!Depressing the brake pedal constantly
results in excessive and premature wear to
the brake pads.
If the brakes have been subjected to a heavy
load, do not stop the vehicle immediately. Drive
on for a short while. This allows the airflow to
cool the brakes more quickly.
Wet roads
If you have driven for a long time in heavy rain
without braking, there may be a delayed reac-
tion from the brakes when braking for the first
time. This may also occur after the vehicle has
been washed or driven through deep water.
You have to depress the brake pedal more
firmly. Maintain a greater distance from the
vehicle in front.
After driving on a wet road or having the vehicle
washed, brake firmly while paying attention to
the traffic conditions. This will warm up the
brake discs, thereby drying them more quickly
and protecting them against corrosion.
Limited braking performance on salt-
treated roads
If you drive on salted roads, a layer of salt resi-
due may form on the brake discs and brake
pads. This can result in a significantly longer
braking distance.
RIn order to prevent any salt build-up, apply the
brakes occasionally while paying attention to
the traffic conditions.
RCarefully depress the brake pedal and the
beginning and end of a journey.
RMaintain a greater distance to the vehicle
ahead.
Servicing the brakes
!The brake fluid level may be too low, if:
Rif the red brake warning lamp lights up in
the instrument cluster and
Ryou hear a warning tone while the engine is
running
Observe additional warning messages in the
multifunction display.
The brake fluid level may be too low due to
brake pad wear or leaking brake lines.
Have the brake system checked immediately.
Consult a qualified specialist workshop to
arrange this.
!Vehicles with 4MATIC: function or per-
formance tests may only be carried out on a 2-
axle dynamometer. If you wish to operate the
vehicle on such a dynamometer, please con-
sult a qualified specialist workshop in
advance. You could otherwise damage the
drive train or the brake system.
!Vehicles with 4MATIC: the ESP®system
operates automatically. If the electric parking
brake is tested on a brake dynamometer, the
engine and ignition must be switched off: turn
the SmartKey in the ignition lock to position
u or1 or press the Start/Stop button
repeatedly in accordance with the given
SmartKey positions.
Braking triggered automatically by ESP
®may
cause severe damage to the brake system.
All checks and maintenance work on the brake
system must be carried out at a qualified spe-
cialist workshop.
Have brake pads installed and brake fluid
replaced at a qualified specialist workshop.
If the brake system has only been subject to
moderate loads, you should test the functional-
ity of your brakes at regular intervals.
Information on BAS (Brake Assist System)
(
Ypage 65) and Active Brake Assist with cross-
traffic function (Ypage 71).
Driving tips149
Driving and parking
Z

For safety reasons, Mercedes-Benz recom-
mends only installing the following brake disks
and brake pads/linings:
Rbrake disks that have been approved by
Mercedes-Benz
Rbrake pads/linings that have been approved
by Mercedes-Benz or that are of an equivalent
standard of quality
Other brake disks or brake pads/linings can
compromise the safety of your vehicle.
Always replace all brake disks and brake pads/
linings on an axle at the same time. Always
install new brake pads/linings when replacing
brake disks.
The vehicle is equipped with lightweight brake
disks to which the wheel assembly with rim and
threaded connection is matched.
The use of brake disks other than those
approved by Mercedes-Benz can change the
track width and is subject to approval, if appli-
cable.
Shock-type loads when handling the brake
discs, such as when changing wheels, can lead
to a reduction in comfort when driving with light-
weight brake discs. Avoid shock-type loads on
the lightweight brake disks, particularly on the
brake plate.
Mercedes-Benz recommends that you only use
brake fluid that has been specially approved for
your vehicle by Mercedes-Benz, or which corre-
sponds to an equivalent quality standard. Brake
fluid which has not been approved for
Mercedes-Benz vehicles or which is not of an
equivalent quality could affect your vehicle's
operating safety.
High-performance and ceramic brakes
(Mercedes-AMG vehicles)
The AMG brake systems are designed for heavy
loads. This may lead to noise when braking. This
will depend on:
RSpeed
RBraking force
REnvironmental conditions, such as tempera-
ture and humidity
The wear of individual components of the brake
system, such as the brake pads/linings or brake
discs, depends on the individual driving style
and operating conditions.
For this reason, it is impossible to state a mile-
age that will be valid under all circumstances. An aggressive driving style will lead to high wear.
You can obtain more information on this from a
qualified specialist workshop.
New and replaced brake pads and discs only
reach their optimum braking effect after several
hundred kilometers of driving. Compensate for
this by applying greater force to the brake pedal.
Keep this in mind, and adapt your driving and
braking accordingly during this break-in period.
Excessive heavy braking results in correspond-
ingly high brake wear. If the brake pads/linings
have reached their wear limit, the multifunction
display shows a corresponding message. Espe-
cially for high performance driving, it is impor-
tant to maintain and have the brake system
checked regularly.
Driving on wet roads
Hydroplaning
If water has accumulated to a certain depth on
the road surface, there is a danger of hydro-
planing occurring, even if:
Ryou drive at low speeds
Rthe tires have adequate tread depth
For this reason, in the event of heavy rain or in
conditions in which hydroplaning may occur,
you must drive in the following manner:
Rlower your speed
Ravoid ruts
Ravoid sudden steering movements
Rbrake carefully
Driving on flooded roads
!Bear in mind that vehicles traveling in front
or in the opposite direction create waves. This
may cause the maximum permissible water
depth to be exceeded.
Failure to observe these notes may result in
damage to the engine, electrical systems and
transmission.
If you have to drive on stretches of road on which
water has collected, please bear in mind that:
Rin the case of standing water, the water level may be no higher than the lower edge of the
vehicle body
Ryou should drive no faster than walking pace
150Driving tips
Driving and parking

Rear view camera
General notes
Rear view camera :is an optical parking and
maneuvering aid. It shows the area behind the
vehicle with guide lines in the multimedia sys-
tem.
The area behind the vehicle is displayed as a
mirror image, as in the rear view mirror.
iThe text shown in the multimedia system
depends on the language setting. The follow-
ing are examples of rear view camera displays
in the multimedia system.
Important safety notes
The rear view camera is only an aid. It is not a
replacement for your attention to your immedi-
ate surroundings. You are always responsible
for safe maneuvering and parking. Make sure
that there are no persons, animals or objects in
the maneuvering area while maneuvering and
parking in parking spaces.
Under the following circumstances, the rear
view camera will not function, or will function in
a limited manner:
Rif the trunk lid is open
Rin heavy rain, snow or fog
Rat night or in very dark places
Rif the camera is exposed to very bright light
Rif the area is lit by fluorescent bulbs or LED
lighting (the display may flicker)
Rif there is a sudden change in temperature,
e.g. when driving into a heated garage in win- ter
Rif the camera lens is dirty or obstructed.
Observe the notes on cleaning
(
Ypage 292)
Rif the rear of your vehicle is damaged. In this
case, have the camera position and setting
checked at a qualified specialist workshop
The field of vision and other functions of the rear
view camera may be restricted due to additional
accessories on the rear of the vehicle (e.g.
license plate holder, rear bicycle rack).
The rear view camera is protected from rain-
drops and dust by means of a flap. When the rear view camera is acti vated
, this flap opens.
The flap closes again when:
Ryou have finished the maneuvering process
Ryou switch off the engine
Ryou open the trunk
Observe the notes on cleaning (
Ypage 292).
For technical reasons, the flap may remain open
briefly after the rear view camera has been
deactivated.
Activating/deactivating the rear view
camera
XTo activate: make sure that the Activa‐
tion by R gearfunction is selected in the
multimedia system (see the Digital Operator's
Manual).
XEngage reverse gear.
The rear view camera flap opens. The multi-
media system shows the area behind the vehi-
cle with guide lines.
The image from the rear view camera is avail- able throughout the maneuvering process.
XTo deactivate: shift the transmission to posi-
tion j.
or
XTo deactivate: Drive forwards at a speed
greater than 7 mph (12 km/h).
Multimedia display
The rear view camera may show a distorted view
of obstacles, show them incorrectly or not at all.
The rear view camera does not show objects in
the following positions:
Rvery close to the rear bumper
Runder the rear bumper
Driving systems173
Driving and parking
Z

Display messagesPossible causes/consequences andMSolutions
The yellow!warning lamp lights up and th ered F (USAonly)
or ! (Canada only) indicator lamp flashes .
It is no tpossibl eto apply th eelectric parking brak emanually.
XShift th etransmission to position j.
XVisitaqualified specialist workshop .
$(USAonly)
J(Canada only)
Check Brake Fluid
Level
There is no tenough brak efluid in th ebrak efluid reservoir .
In addition ,th e$ (USAonly) or J(Canada only) warning lamp
lights up in th einstrumen tcluste rand awarning tone sounds.
GWARNIN G
The braking effec tmay be impaired.
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. Do no tcontinu edrivin g
under any circumstances.
XSecur eth evehicl eagainst rollin gaway (Ypage 143).
XConsult aqualified specialist workshop .
XDo notadd brak efluid .This does no tcorrec tth emalfunction .
#
CheckBrakePadWear
The brak epads/linings hav ereached their wear limit.
US Aonly: th e$ red brak esystem warning lamp is lit while th e
engin eis running.
XVisit aqualified specialist workshop .
G
Inoperative
Oneor mor emain features of th embrace system are malfunctioning .
XVisitaqualified specialist workshop .
ActiveBrakeAssistFunctionsCurrentlyLimitedSee Opera‐tor's Manual
Active Brake Assis tis 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.
Whe nth ecauses state dabov eno longer apply, th edisplay message
disappears.
Active Brake Assis tis 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.
218Display messages
On-board computer and displays