2012 MERCEDES-BENZ E-CLASS CABRIOLET check engine light

Key functions
:
& To loc kthe vehicle
; F To unlock the boot lid
= % To unlock the vehicle
X To unlock centrally: press the%but-
ton.
If you do not open the vehicle within
approximately 40 seconds of unlocking:
R the vehicle is locked again.
R the anti-theft system is primed again.
X To lock centrally: press the&button.
The key centrally locks/unlocks:
R the doors
R the boot lid
R the fuel filler flap
When unlocking, the turn signals flash once.
When locking, they flash three times.
You can also set an audible signal to confirm
that the vehicle has been locked. The audible
signal can be activated and deactivated using
the on-board computer (Y page 245).
When it is dark, the surround lighting also
comes on if it is activated in the on-board
computer (Y page 244). KEYLESS-GO
General notes Bear in mind that the engine can be started
by any of the vehicle occupants if there is a
KEYLESS-GO key in the vehicle. Locking and unlocking centrally You can start, lock or unlock the vehicle using
KEYLESS-GO. To do this, you only need carry
the key with you. When you touch the surface
of the sensors on the vehicle's outside door
handles, KEYLESS-GO establishes a radio
connection between the vehicle and the key.
When the engine is started and whilst you are
driving, KEYLESS-GO also checks whether a
valid key is in the vehicle by periodically
establishing radio contact.
You can combine the KEYLESS-GO functions
with those of a conventional key, e.g. using
KEYLESS-GO to unlock and pressing the
&
button to lock.
When locking or unlocking with KEYLESS-GO,
the distance between the key and the corre-
sponding door handle must not be greater
than 1 m. X
To unlock the vehicle: touch the inner
surface of the door handle.
X To lock the vehicle: touch sensor sur-
face :.
X Convenience closing feature: touch
recessed sensor surface ;for an exten-
ded period.
X To unlock the boot lid: pull the handle on
the boot lid.
Further information on the convenience clos-
ing feature (Y page 90). Key
77Opening and closing Z

Problem Possible causes/consequences and
M Solutions
You have lost the emer-
gency key element. X
Report the loss immediately to the vehicle insurers.
X If necessary, have the locks changed as well. The engine cannot be
started using the key. the on-board voltage is too low.
X
Switch off non-essential consumers, e.g. seat heating or interior
lighting, and try to start the engine again.
If this does not work:
X Check the starter battery and charge it if necessary
(Y page 330).
or
X Jump-start the vehicle (Y page 331).
or
X Consult a qualified specialist workshop. Only vehicles without a
DIRECT SELECT lever:
The engine cannot be
started using the key. The steering lock is mechanically blocked.
X
Remove the key and reinsert it into the ignition lock. While doing
this, turn the steering wheel in both directions. The engine cannot be
started using KEYLESS-
GO. The key is in the
vehicle. Ad
oor is open. Therefore, the key cannot be detected as easily.
X Close the door and try to start the vehicle again. There is interference from a powerful source of radio waves.
X
Start your vehicle with the key in the ignition lock. Doors
Important safety notes
G
WARNING
Only for the United Kingdom: if the vehicle
has been locked with the key or with KEY-
LESS-GO, the double lock function is activa-
ted as standard. It is then not possible to open
the doors from inside the vehicle.
Therefore, do not leave any people behind in
the vehicle, particularly children, elderly peo-
ple or people requiring special assistance. As
a result, they may not be able to free them-
selves in the event of an emergency. They
could be seriously or even fatally injured by
prolonged exposure to extremely high or low
temperatures, for example. In this case, res- cuing people from outside the vehicle is diffi-
cult.
Deactivate the interior motion sensor before
you lock the vehicle. The doors can then be
opened from the inside after the vehicle has
been locked from the outside.
G
WARNING
If children are left unsupervised in the vehicle,
they could:
R open a door from inside the vehicle at any
time, even if it has been locked
R start the vehicle using akey which has been
left in the vehicle
R release the parking brake 82
DoorsOpening and closing

The interior lighting automatically switches
on if you:
R unlock the vehicle
R open a door
R remove the key from the ignition lock
The interior lighting is activated for a short
time when the key is removed from the igni-
tion lock. You can activate this delayed
switch-off using the on-board computer
(Y page 245).
Manual interior lighting control Front overhead control panel
:
u To switch the rear interior lighting
on/of f(Coupé only)
; | To switch the automatic interior
lighting control on/off
= p To switch the right-hand reading
lamp on/off
? c To switch the front interior lighting
on/off
A p To switch the left-hand reading lamp
on/off
X To switch the front interior lighting on/
off: press the cbutton.
X To switch the rea rinterior lighting on/
off (Coupé only): press theubutton.
X To switch the reading lamps on/off:
press the pbutton. Crash-responsive emergency lighting
The interior lighting is activated automatically
if the vehicle is involved in an accident.
X To switch off the crash-responsive
emergency lighting: press the hazard
warning lamp button.
or
X Lock and then unlock the vehicle using the
key. Replacing bulbs
Important safety notes
Xenon bulbs G
DANGER
Xenon bulbs are under high voltage. If you
touch the electrical contacts of a xenon bulb,
you could suffer an electric shock and be seri-
ously or even fatally injured. For this reason,
do not remove the cover of xenon bulbs.
Do not change the xenon bulbs yourself, but
have them replaced at a qualified workshop.
If your vehicle is equipped with xenon bulbs,
you can recognise this by the following: the
cone of light from the xenon bulbs moves
from the top to the bottom and back again
when you start the engine. For this to be
observed, the lights must be switched on
before starting the engine.
Bulbs and lamps are an important aspect of
vehicle safety. You must therefore make sure
that these function correctly at all times.
Have the headlamp setting checked regularly.
Other bulbs G
WARNING
Bulbs and lamps can be very hot. You should
therefore allow them to cool down before you
change them. Otherwise, you could be burned
if you touch them. 132
Replacing bulbsLights and windscreen wipers

Problem Possible causes/consequences and
M Solutions
Vehicles with a petrol
engine:
The engine is not run-
ning smoothly and is
misfiring. There is a malfunction in the engine electronics or in a mechanical
component of the engine management system.
X
Only depress the accelerator pedal slightly.
Otherwise, non-combusted fuel may get into the catalytic con-
verter and damage it.
X Have the cause rectified immediately at a qualified specialist
workshop. The coolant tempera-
ture display is showing
more than 120 †. The
coolant warning lamp
may also be lit and a
warning tone may
sound. The coolant level is too low. The coolant is too hot and the engine
is no longer being cooled sufficiently.
X
Stop as soon as possible and allow the engine and the coolant
to cool down.
X Check the coolant level (Y page 310). Observe the warning
notes as you do so and top up the coolant if necessary. If the coolant level is correct, the engine radiator fan may be faulty.
The coolant is too hot and the engine is no longer being cooled
sufficiently.
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. Manual transmission
Important safety notes
G
WARNING
The movement of the pedals must not be
impaired in any way. Do not keep any objects
in the driver's footwell. Make sure that floor-
mats or carpets are correctly secured and
that there is sufficient clearance for the ped-
als.
Do not place several floormats on top of one
another. G
WARNING
Do not change down for additional engine
braking on a slippery road surface. This could
cause the drive wheels to lose their grip and
the vehicle could skid. This could cause you to lose control of your vehicle and cause an
accident.
Gear lever
! Only engage gear when the clutch pedal
is depressed.
! When shifting between 5thand 6thgear,
you should always push the gear lever all
the way to the right. Otherwise, you could
shift unintentionally into 3rdor4th gear
and damage the transmission.
If you shift down at too high a speed (trans-
mission braking), this can cause the engine
to overrev, leading to engine damage.
Do not use the clutch bite point to keep the
vehicle stationary on uphill gradients.
There is otherwise a risk of damaging the
clutch. 166
Manual transmissionDriving and parking

or winding roads). You may otherwise
cause an accident.
R on slippery roads. The drive wheels may
lose their grip when braking or accelerating
and the vehicle may skid.
R when there is low visibility, e.g. due to fog,
heavy rain or snow.
General notes Cruise control maintains a constant road
speed for you. It brakes automatically in order
to avoid exceeding the set speed. You must
select a low gear in good time on long and
steep downhill gradients, especially if the
vehicle is laden or towing a trailer. On vehicles
with automatic transmission, select shift
range 1,2or 3.B y doing so, you will make
use of the braking effec tofthe engine. This
relieves the load on the brake system and
prevents the brakes from overheating and
wearing too quickly.
Use cruise control only if road and traffic con-
ditions make it appropriate to maintain a
steady speed for a prolonged period. You can
store any road speed above 30 km/h.
Cruise control lever :
To activate or increase speed
; LIM indicator lamp
= To activate at the current speed/last
stored speed
? To activate or reduce speed A
To switch between cruise control and var-
iable SPEEDTRONIC
B To deactivate cruise control
You can operate cruise control and variable
SPEEDTRONIC with the cruise control lever.
The LIM indicator lamp on the cruise control
lever indicates which system you have selec-
ted:
R LIM indicator lamp off: cruise control is
selected.
R LIM indicator lamp on: variable SPEED-
TRONIC is selected.
When you activate cruise control, the stored
speed is shown in the multifunction display
for five seconds. In the multifunction display,
the segments between the stored speed and
the maximum speed light up.
Activation conditions To activate cruise control, all of the following
activation conditions must be fulfilled:
R
the parking brake must be released.
R you must be driving faster than 30 km/h.
R ESP ®
must be switched on, but not inter-
vening.
R the transmission must be in position D.
R the cruise control function must be selec-
ted (Y page 183).
Selecting cruise control X
Check whether LIM indicator lamp :is off.
If it is off, cruise control is already selected. Driving systems
183Driving and parking Z

:
Yellow indicator lamp/red warning lamp
If Blind Spot Assist is switched on, indicator
lamp :in the exterior mirrors lights up yel-
low up to a speed of 30 km/h. At speeds
above 30 km/h, the indicator lamp goes out
and Blind Spot Assist is operational.
If a vehicle is detected within the monitoring
range of Blind Spot Assist at speeds above
30 km/h, warning lamp :on the corre-
sponding side lights up red. This warning
always occurs when a vehicle enters the blind
spot monitoring rang efrom behind or from
the side .When you overtake a vehicle, the
warning only occurs if the difference in speed
is less than 12 km/h.
The yellow indicator lamp goes out if reverse
gear is engaged. Blind Spot Assist is then
deactivated.
The brightness of the indicator/warning
lamps is adjusted automatically according to
the ambient light.
Collision warning
If a vehicle is detected in the monitoring range
of Blind Spot Assist and you switch on the
corresponding turn signal, a double warning
tone sounds. Red warning lamp :flashes. If
the turn signal remains on, detected vehicles
are indicated by the flashing of red warning
lamp :.There are no further warning tones.
Switching on Blind Spot Assist
X Make sure that the radar sensor system
(Y page 245) and Blind Spot Assist (Y
page 241) are activated in the on-board
computer.
X Turn the key to position 2in the ignition
lock.
Warning lamps :in the exterior mirrors
light up red for approximately
1.5 seconds and then turn yellow.
Towing atrailer
If you attach a trailer, make sure tha tyou have
correctly established the electrical connec-
tion. This can be accomplished by checking
the trailer lighting. Blind Spot Assist is then
deactivated. The indicator lamp lights up yel-
low in the exterior mirrors and the message:
Blind Spot Assist currently unavail‐
able See Owner's Manual appears in the
multifunction display.
i You can deactivate the indicator lamps in
the exterior mirrors.
To do so, switch off Blind Spot Assist if:
R the key is in position 2in the ignition
lock.
R the engine is not running.
R the electrical connection to the trailer
has been established.
Lane Keeping Assist Important safety notes
G
WARNING
Lane Keeping Assist does not keep your vehi-
cle in its lane. It is only an aid and may detect
the lane markings on the road incorrectly or
not at all.
The system may be impaired or may not func-
tion if:
R there is poor visibility, e.g. due to insuffi-
cient illumination of the road, or due to
snow, rain, fog or spray.
R there is glare, e.g. from oncoming traffic,
the sun, or reflection from other vehicles. 212
Driving systemsDriving and parking

X
Press the abutton.
The multifunction display shows Speed
Limit Assist.
X Press the :button.
The curren tselection is displayed.
X To activate or deactivate: pressa.
If the Speed Limit Assist message function
is activated, a detected speed limit is auto-
matically displayed for five seconds. Other
items in the multifunction display are not
shown during this time.
If Speed Limit Assist is operational and the
message function is activated, the multifunc-
tion display shows the Äsymbol when the
ignition is switched on.
Showing the distance display X
Press the =or; button on the steer-
ing wheel to select the Assist. menu.
X Press the 9or: button to select
Distance display .
X Press the abutton.
The DISTRONIC PLUS distance display
appears in the multifunction display
(Y page 195).
If the Sensors deactivated message
appears, the radar sensor system is deacti-
vated.
X Check whether or not the radar sensor sys-
tem is permitted to be activated
(Y page 382).
X Switch on the radar sensor system
(Y page 245).
Deactivating/activating ESP ®G
WARNING
If you deactivate ESP ®
, ESP ®
no longer sta-
bilises the vehicle. There is an increased risk
of skidding and an accident.
Only deactivate ESP ®
in the situations descri-
bed in the following. For further information about ESP
®
, see
(Y page 67).
X Start the engine.
X Press the =or; button on the steer-
ing wheel to select the Assist. menu.
X Press the 9or: button to select
ESP .
X Press the abutton.
The curren tselection is displayed.
X To activate/deactivate: press thea
button again.
ESP ®
is deactivated if the åwarning lamp
in the instrument cluster lights up continu-
ously when the engine is running.
If the ä warning lamp and the åwarn-
ing lamp are lit continuously, ESP ®
is not
available due to a malfunction.
It may be best to deactivate ESP ®
in the fol-
lowing situations:
R when using snow chains
R in deep snow
R on sand or gravel
Observe the information on warning lamps
(Y page 278).
Observe the information on display messages
(Y page 250).
Activating/deactivating the PRE-SAFE ®
Brake PRE-SAFE
®
Brake is only available in vehicles
with DISTRONIC PLUS.
X Press the =or; button on the steer-
ing wheel to select the Assist. menu.
X Press the 9or: button to select
PRE-SAFE Brake .
X Press the abutton.
The curren tselection is displayed.
X To activate/deactivate: press thea
button again.
When PRE-SAFE ®
Brake is activated, the mul-
tifunction display shows the Äsymbol as 240
Menus and submenusOn-board computer and displays

Display messages Possible causes/consequences and
M Solutions
J
Check brake fluid
level There is insufficien
tbrake fluid in the brake flui dreservoir.
In addition, the red Jwarning lamp lights up in the instrument
cluster and a warning tone sounds.
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 .Donot continue driving
under any circumstances.
X Secure the vehicle against rolling away (Y page 177).
X Consult a qualified specialist workshop.
X Do not top up the brake fluid. This does not correct the error. #
Check brake pad
wear The brake pads/linings have reached their wear limit.
X Visit a qualified specialist workshop. PRE-SAFE
inoperative See
Owner's Manual Important functions of PRE-SAFE
®
have failed. All other occupant
safety systems, e.g. airbags, remain available.
X Visit a qualified specialist workshop immediately. PRE-SAFE
Functions cur‐
rently limited See
Owner's Manual PRE-SAFE
®
Brake is temporarily inoperative. Possible causes:
R the function is impaired due to heavy rain or snow.
R the sensors in the radiator trim and in the bumpers are dirty.
R the radar sensor system is temporarily inoperative, e.g. due to
electromagnetic radiation emitted by nearby TV or radio sta-
tions or other sources of electromagnetic radiation.
R the system is outside the operating temperature range.
R the on-board voltage is too low.
Once the causes listed above no longer apply, the display message
goes out.
PRE-SAFE ®
Brake is operational again.
If the display message does not disappear:
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 Clean the sensors in the radiator trim and in the bumpers
(Y page 317).
X Restart the engine. Display messages
253On-board computer and displays Z