2012 MERCEDES-BENZ E-CLASS CABRIOLET check engine light

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

Problem Possible causes/consequences and
M Solutions
ä
The yellow ESP
®
warn-
ing lamp flashes while
the vehicle is in motion. ESP
®
or traction control has intervened because there is a risk of
skidding or at least one wheel has started to spin.
Cruise control or DISTRONIC PLUS is deactivated.
X Only depress the accelerator pedal as far as necessary when
pulling away.
X Accelerate more gently while the vehicle is in motion.
X Adapt your driving style to suit the road and weather conditions.
X Do not deactivate ESP ®
.
For exceptions, see: (Y page 67).å
The yellow ESP
®
OFF
warning lamp is lit while
the engine is running. ESP
®
is deactivated.
G WARNING
If ESP ®
is switched off, ESP ®
is unable to stabilise the vehicle.
The danger of skidding and having an accident increases.
X Reactivate ESP ®
.
For exceptions, see: (Y page 67).
X Adapt your driving style to suit the road and weather conditions.
If ESP ®
cannot be activated:
X Drive on carefully.
X Have ESP ®
checked at a qualified specialist workshop. äå
The yellow ESP
®
and
ESP ®
OFF warning
lamps are lit while the
engine is running. ESP
®
, BAS, BAS PLUS, PRE-SAFE ®
, PRE-SAFE ®
Brake, the HOLD
function, hill start assist, the adaptive brake lights and ESP ®
trailer
stabilisation are not available due to a malfunction.
ATTENTION ASSIST is deactivated.
G WARNING
The brake system continues to function normally, but without the
functions listed above.
The braking distance in an emergency braking situation can thus
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. Warning and indicator lamps in the instrument cluster
279On-board computer and displays Z

Problem Possible causes/consequences and
M Solutions
J
The red brake system
warning lamp comes on
while the vehicle is
moving. A warning tone
also sounds.
You are driving with the parking brake applied.
X
Release the parking brake.
The warning lamp goes out and the warning tone ceases. 6
The red SRS warning
lamp is lit while the
engine is running.
There is a malfunction in the SRS (Supplemental Restraint Sys-
tem).
G WARNING
The airbags or belt tensioners may either be triggered uninten-
tionally or, in the event of an accident, may not be triggered.
This poses an increased risk of injury.
X Drive on carefully.
X Have SRS checked at a qualified specialist workshop immedi-
ately.
For further information about the Supplemental Restraint System,
see (Y page 41). Engine
Problem Possible causes/consequences and
M Solutions
;
The yellow engine diag-
nostics warning lamp
lights up while the
engine is running. There may be a fault, for example:
R
in the engine management
R in the fuel injection system
R in the exhaust system
R in the ignition system (for vehicles with petrol engines)
R in the fuel system
The emission limit values may be exceeded and the engine may
be running in emergency mode.
X Have the vehicle checked as soon as possible at a qualified
specialist workshop. Vehicles with a diesel engine: the fuel tank has been run dry
(Y
page 176).
X Start the engine three to four times after refuelling.
If the yellow engine diagnostics warning lamp goes out, emer-
gency running mode is cancelled. The vehicle need not be
checked. 280
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

tha
tno ignition position has been selected
with KEYLESS-GO. All indicator lamps must be
off in the instrument panel.
! Make sure that the windscreen wipers are
not folded away from the windscreen. Oth-
erwise, you could damage the windscreen
wipers or the bonnet. X
Make sure that the windscreen wipers are
switched off.
X Pull release lever :on the bonnet.
The bonnet is released. X
Reach into the gap, pull bonnet catch han-
dle ;up and lift the bonnet.
If you lift the bonnet by approximately
40 cm, the bonnet is opened and held open
automatically by the gas-filled strut.
Closing the bonnet G
WARNING
Make sure that nobody can become trapped
as you close the bonnet. X
Lower the bonnet and let it fall from a
height of approximately 20 cm.
X Check that the bonnet has engaged prop-
erly.
If the bonnet can be raised slightly, it is not
properly engaged. Open it again and close
it with a little more force. Radiator
Vehicles with adiesel engine: do not cover
the radiator .Do not use thermal mats, insect
protection covers or anything similar. Doing
so can cause the Onboard Diagnostics Sys-
tem to display inaccurate values. Some of
these values are legally required and must
always be correct. Engine oil
General notes Depending on your driving style, the vehicle
consumes up to 0.8 l of oil per 1,000 km. The
oil consumption may be higher than this when
the vehicle is new or if you frequently drive at
high engine speeds.
Depending on the engine, the oil dipstick may
be installed at a different location.
When checking the oil level:
R park the vehicle on a level surface.
R the engine should be switched off for
approximately five minutes if the engine is
at normal operating temperature.
R if the engine is not at normal operating
temperature, e.g. if the engine was only
started briefly: wait about 30 minutes
before carrying out the measurement. 308
Engine compartmentMaintenance and care

!
When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses. X
To open: pull out cover :slightly at the
bottom in the direction of arrow =.
X Pull cover :outwards in the direction of
arrow ;and remove it.
X To close: clip in cover :on the front of
the dashboard.
X Fold cover :inwards until it engages. Fuse box in the engine compartment
G
WARNING
Make sure that the windscreen wipers are
turned off and the key is pulled out of the igni-
tion lock before you open the cover of the fuse
box. Otherwise, the windscreen wipers and
the wiper rods above the cover could be set
in motion. This could lead to you or others
being injured by the wiper rods.
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses.
X Make sure that the windscreen wipers are
switched off.
X Open the bonnet. X
Remove any existing moisture from the
fuse box using a dry cloth.
X To open: take lines ;from the guides.
X Move aside lines ;.Route the lines behind
connection =to do this.
X Open clamps :.
X Remove the fuse box cover forwards.
X To close: check whether the rubber seal is
lying correctly in the cover.
X Insert the cover at the rear of the fuse box
into the retainer.
X Fold down cover and close clamps :.
X Secure lines ;in the guides.
X Close the bonnet. Fuse box in the boot
! Make sure that no moisture can enter the
fuse box when the cover is open.
! When closing the cover, make sure that it
is lying correctly on the fuse box. Moisture
seeping in or dirt could otherwise impair
the operation of the fuses.
X Open the boot lid. Electrical fuses
337Breakdown assistance Z