2012 MERCEDES-BENZ E-CLASS CABRIOLET stop start

Key
Display messages Possible causes/consequences and
M Solutions
Â
Key does not
belong to vehicle You have put the wrong key in the ignition lock.
X
Use the correct key. Â
Replace key The key needs to be replaced.
X
Visit a qualified specialist workshop. Â
Change key batter‐
ies The batteries of the KEYLESS-GO key are discharged.
X
Change the batteries ( Ypage 79). Â
Key not detected
(red display message) The KEYLESS-GO key is not in the vehicle.
Aw
arning tone also sounds.
If the engine is switched off, you can no longer loc kthe vehicle
centrally or start the engine.
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 Locate the KEYLESS-GO key. The KEYLESS-GO key is not detected while the engine is running
because there is interference from a strong source of radio waves.
Aw
arning tone also sounds.
X Pull ove rand stop the vehicle safely as soo nas possible, paying
attention to road and traffic conditions.
X Secure the vehicle against rolling away (Y page 177).
X Operate the vehicle with the key in the ignition lock if necessary. Â
Key not detected
(white display mes-
sage) The KEYLESS-GO key cannot be detected at present.
X
Change the location of the key with the KEYLESS-GO functions
in the vehicle.
If the KEYLESS-GO key is still not detected:
X Operate the vehicle with the key in the ignition lock if necessary. Â
Key still in vehi‐
cle The KEYLESS-GO key has been detected inside the vehicle during
locking.
X
Remove the KEYLESS-GO key from the vehicle. 274
Display messagesOn-board computer and displays

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. There is insufficient brake fluid in the brake fluid reservoir.
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. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 177).
X Do not top up the brake fluid. Topping up will not rectify the
fault.
X Consult a qualified specialist workshop.
X Observe the additional display messages in the multifunction
display. !
The yellow ABS warning
lamp is lit while the
engine is running. 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.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above. The wheels could therefore lock if you
brake hard, for example.
The steerability and braking characteristics may be severely affec-
ted. The braking distance in an emergency braking situation can
increase.
If ESP ®
is not operational, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
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
277On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
8
The yellow reserve fuel
warning lamp lights up
while the engine is run-
ning.
The fuel level has dropped into the reserve range.
Operation of the auxiliary heating is deactivated if the fuel level
drops into the reserve range.
X
Refuel at the nearest filling station. ?
The red coolant warn-
ing lamp lights up while
the engine is running
and the coolant tem-
perature gauge is at the
start of the scale.
The temperature sensor for the coolant temperature gauge is
faulty.
The coolant temperature is no longer being monitored. There is a
risk of engine damage if the coolant temperature is too high.
X
Stop the vehicle immediately, paying attention to road and traf-
fic conditions, and switch off the engine. Do not continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 177).
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
281On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning.
The coolant level is too low.
If the coolant level is correct, the airflow to the engine radiator
may be blocked or the electric engine radiator fan may be mal-
functioning.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
X
Observe the additional display messages in the multifunction
display.
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 Check the coolant level and top up the coolant, observing the
warning notes (Y page 310).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
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 coolant temperature is
under 120 †. The engine may otherwise be damaged.
X Drive 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. ?
The red coolant warn-
ing lamp comes on
while the engine is run-
ning. A warning tone
also sounds.
The coolant temperature has exceeded 120 †. The airflow to the
engine radiator may be blocked or the coolant level may be too
low.
G WARNING
The engine is not being cooled sufficiently and may be damaged.
Never drive with an overheated engine. Driving when your engine
is overheated can cause some fluids which may have leaked into
the engine compartment to catch fire.
Steam from an overheated engine can cause serious burns, which
can occur just by opening the bonnet.
This poses a risk of injury.
X Observe the additional display messages in the multifunction
display.
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).282
Warning and indicator lamps in the instrument clusterOn-board computer and displays

Problem Possible causes/consequences and
M Solutions
X
Leave the vehicle and keep a safe distance from the vehicle until
the engine has cooled down.
X Check the coolant level and top up the coolant, observing the
warning notes (Y page 310).
X If you have to top up the coolant frequently, have the engine
cooling system checked.
X Make sure that the air supply to the engine radiator is not
blocked, e.g. by frozen slush.
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. Driving systems
Problem Possible causes/consequences and
M Solutions
·
The red distance warn-
ing lamp lights up while
the vehicle is in motion.
The distance to the vehicle in front is too small for the speed
selected.
X Increase the distance. ·
The red distance warn-
ing lamp lights up while
the vehicle is in motion.
Aw
arning tone also
sounds. You are approaching a vehicle or a stationary obstacle in your line
of travel at too high a speed.
X
Be prepared to brake immediately.
X Pay careful attention to the traffic situation. You may have to
brake or take evasive action.
Further information on DISTRONIC PLUS (Y page 188).
Further information on PRE-SAFE ®
Brake (Y page 69). Warning and indicator lamps in the instrument cluster
283On-board computer and displays Z

Other service products
Checking the coolant level G
WARNING
The cooling system is pressurised. Therefore,
only unscrew the cap once the engine has
cooled down. The coolant temperature gauge
must display less than 70 †.Otherwise, you
could be scalded if hot coolant escapes. X
Park the vehicle on a level surface.
Only check the coolant level if the vehicle
is on a level surface and the engine has
cooled down.
X Turn the key to position 2in the ignition
lock (Y page 159).
On vehicles with KEYLESS-GO, press the
Start/Stop button twice (Y page 159).
X Check the coolant temperature display in
the instrument cluster.
The coolant temperature must be below
70 †.
X Turn the key to position 0(Y page 159) in
the ignition lock.
X Slowly tur ncap : half a turn anti-clock-
wise to allow excess pressure to escape.
X Turn cap :further anti-clockwise and
remove it.
If the coolant is at the level of marker bar
= in the fille rneck when cold, there is
enough coolant in coolant expansion
tank ;.
If the coolant level is approximately
1.5 cm above marker bar =in the filler neckw
hen warm, there is enough coolant
in coolant expansion tank ;.
X If necessary, top up with coolant that has
been tested and approved by Mercedes-
Benz.
X Replace cap :and turn it clockwise as far
as it will go.
For further information on coolant, see
(Y page 376).
Topping up the windscreen washer sys-
tem/headlampc leaning system G
WARNING
Windscreen washer fluid/antifreeze is highly
flammable. Avoid spilling windscreen washer
fluid/antifreeze on hot engine components as
it can ignite and burn. Severe burns could be
the result. X
To open: pull cap:upwards by the tab.
X Top up with the premixed washer fluid.
X To close: press cap :onto the filler neck
until it engages.
The washer fluid reservoir is used for both the
windscreen washer syste mand the headlamp
cleaning system.
Further informatio nonwindscreen washer
fluid/antifreeze (Y page 377).310
Engine compartmentMaintenance and care

Cleaning AIRCAP
Cleaning the wind deflector
!
Do no tuse high-pressure cleaning equip-
ment to clean the net.
Cleant he wind deflector on the windscreen
with the soft top closed.
X Apply the parking brake firmly.
X Vehicles with key: turn the key to position
2 (Y page 159) in the ignition lock.
X Vehicles with KEYLESS-GO: press the
Start/Stop button twice (Y page 159).
X Open the cover on the lower centre con-
sole.
The AIRCAP button is under the cover. X
Press AIRCAP button :.
The wind deflector between the wind-
screen and the soft top is extended. X
Cleann et; of the wind deflector with a
soft brush or a moist cloth. For heavier soil-
ing, clean it with the care and cleaning
agents recommended and approved by Mercedes-Benza
nd rinse it with clean
water.
Cleaning the AIRCAP draught stop
Clea nthe AIRCAP draught stop with the soft
top open.
X Vehicles with key: turn the key to position
2 (Y page 159) in the ignition lock.
X Vehicles with KEYLESS-GO: press the
Start/Stop button twice (Y page 159).
X Open the soft top (Y page 93). X
Press rear seat head restraints button :.
The rear seat head restraints and AIRCAP
draught stop rise upwards. X
Cleann et; of the AIRCAP draught stop
with a moist cloth together with the care
and cleaning agents recommended and
approved by Mercedes-Benz.
Cleaning the wheels !
Do not use acidic wheel cleaning products
to remove brake dust. This could damage
wheel bolts and brake components. Care
315Maintenance and care Z

!
Do not park up the vehicle for an extended
period straight after cleaning it, particularly
after having cleaned the wheels with wheel
cleaner. Wheel cleaners could cause
increased corrosion of the brake discs and
brake pads/linings. For this reason, you
should drive for a few minutes after clean-
ing. Braking heats the brake discs and the
brake pads/linings, thus drying them. The
vehicle can then be parked up.
Cleaning the windows G
WARNING
Switch off the windscreen wipers and remove
the key from the ignition lock before cleaning
the windscreen or the wiper blades. On vehi-
cles with KEYLESS-GO, press the Start/Stop
button repeatedly until all indicator lamps in
the instrument cluster have gone off. The
windscreen wipers could otherwise move and
injure you.
! Do not use dry cloths, abrasive products,
solvents or cleaning agents containing sol-
vents to clean the inside of the windows.
Do not touch the insides of the windows
with hard objects, e.g. an ice scraper or
ring. There is otherwise a risk of damaging
the windows.
! Cleant he water drainage channels of the
windscreen and the rear window at regular
intervals. Deposits such as leaves, petals
and pollen may under certain circumstan-
ces prevent water from draining away.T his
can lead to corrosion damage and damage
to electronic components.
X Cleant he inside and outside of the win-
dows with a damp cloth and a cleaning
agent that is recommended and approved
by Mercedes-Benz.
Cleaning the wiper blades G
WARNING
Switch off the windscreen wipers and remove
the key from the ignition lock before cleaning the windscreen or the wiper blades. On vehi-
cles with KEYLESS-GO, press the Start/Stop
button repeatedly until all indicator lamps in
the instrument cluster have gone off. The
windscreen wipers could otherwise move and
injure you.
! Do not pull on the wiper blade. Otherwise,
the wiper blade could be damaged.
! Do not clean wiper blades too often and
do not rub them too hard. Otherwise, the
graphite coating could be damaged. This
could cause wiper noise.
! Hold the wiper arm securely when folding
back. The windscreen could be damaged if
the wiper arm hits against it suddenly.
X Fold the wiper arms away from the wind-
screen.
X Carefully clean the wiper blades with a
damp cloth.
X Fold the windscreen wipers back again
before switching on the ignition.
Cleaning the exterior lighting !
Only use cleaning agents or cleaning
cloths that are suitable for plastic lenses.
Unsuitable cleaning agents or cleaning
cloths could scratch or damage the plastic
lenses of the exterior lighting.
X Cleant he plastic lenses of the exterior
lighting using a wet sponge and a mild
cleaning agent, e.g. Mercedes-Ben zcar
shampoo or cleaning cloths.
Mirror turn signal !
Only use cleaning agents or cleaning
cloths that are suitable for plastic lenses.
Unsuitable cleaning agents or cleaning
cloths could scratch or damage the plastic
lenses of the mirror tur nsignals.
X Clean the plasti clenses of the mirror turn
signals in the exterior mirror housing using
a wet sponge and mild cleaning agent, e.g. 316
CareMaintenance and care