2015 MERCEDES-BENZ E-CLASS CABRIOLET battery

Folding in the ball coupling
i
Fold the ball coupling back in if you are not
using the trailer tow hitch.
X Place the protective covering on the ball cou-
pling.
Opening the cover: X Turn handle :anti-clockwise and fold down
cover ;.
Unlocking and lowering the ball coupling:
X Pull out release wheel ?.
X Turn release wheel ?anti-clockwise.
The ball coupling unlocks and lowers. Indica-
tor lamp =flashes.
X Press the ball coupling in the direction of the
arrow until it engages behind the bumper.
Indicator lamp =goes out and the message
in the multifunction display disappears. Coupling up a trailer
X Make sure that the transmission is in position
P .
X Apply the parking brake.
X Position the trailer horizontally behind the
vehicle.
X Couple up the trailer.
X Establish the electric connection between the
vehicle and the trailer.
X Check that the trailer lighting system is work-
ing.
A connected trailer is only recognised when
the electrical connection is established cor-
rectly and when the lighting system is working
properly. The function of other systems, such
as ESP ®
, PARKTRONIC and Active Parking
Assist also depends on this. Uncoupling a trailer
G
WARNING
If you uncouple a trailer with an engaged over- run brake, you could trap your hand between
the vehicle and the trailer drawbar. This poses a risk of injury.
Do not uncouple a trailer with an engaged
overrun brake. G
WARNING
Vehicles with level control:
If you disconnect the trailer cable, the vehicle is lowered. This can cause you or others to
become trapped between the vehicle body
and tyres, or underneath the vehicle. This
poses a risk of injury.
Make sure that no-one is in the immediate
vicinity of the wheel arch or underneath the
vehicle when disconnecting the trailer cable.
! Do not disconnect a trailer with an engaged
overrun brake. Otherwise, your vehicle could
be damaged by the rebounding of the overrun
brake.
X Make sure that the transmission is in position
P.
X Apply the parking brake.
X Secure the trailer against rolling away.
X Remove the trailer cable and decouple the
trailer. Trailer power supply
! You can connect accessories to the perma-
nent power supply up to a maximum of 240 W.
You cannot charge a trailer battery using the
power supply.
X To switch the connected power supply on
or off: turn the key in the ignition lock to
position 2or 0respectively (Y page 139).
When it leaves the factory, your vehicle's trailer
socket is equipped with a permanent power
supply and a power supply that is switched on
via the ignition lock.
The permanent power supply is supplied via
trailer socket pin 9.
The power supply that is switched on via the
ignition lock is supplied via trailer socket pin 10.
The trailer's permanent power supply is
switched off in the event of low vehicle supply
voltage and after six hours at the latest.
You can find more information about fitting the
trailer electrics at a qualified specialist work-
shop. Towing a trailer
211Driving and parking Z

X
Press the :or9 button to select the
Automatic door locks
Automatic door locks function.
If the Autom. locking
Autom. locking function is switched
on, the multifunction display shows the vehi-
cle's doors in orange.
X Press the abutton to save the setting.
If you activate the Auto.
Auto. door
doorlocks
locks function,
the vehicle is centrally locked above a speed of around 15 km/h.
For further information on the automatic locking feature; see (Y page 82).
Activating/deactivating the acoustic
locking confirmation If you switch on the Acoustic AcousticLock
Lockfunction, an
acoustic signal sounds when you lock the vehi-
cle.
X Press the =or; button on the steering
wheel to select the Settings Settingsmenu.
X Press the :or9 button to select the
Vehicle
Vehicle submenu.
X Press ato confirm.
X Press the :or9 button to select the
Acoustic Lock
Acoustic Lock function.
If the Acoustic Lock
Acoustic Lock function is activated,
the & symbol in the multifunction display
lights up orange.
X Press the abutton to save the setting.
Heating Auxiliary heating departure time
G
DANGER
If the exhaust pipe is blocked or sufficient
ventilation is not possible, toxic exhaust
fumes can enter the vehicle, especially car-
bon monoxide. This is the case, e.g. in
enclosed spaces, or if the vehicle is stuck in
snow. There is a risk of fatal injuries.
You should switch off the auxiliary heating in
enclosed spaces which do not have an extrac- tion system, e.g. a garage. If the vehicle is
stuck in snow and you must leave the auxiliary
heating running, keep the exhaust pipe and
the area around the vehicle clear of snow. To guarantee a sufficient supply of fresh air, open
a window on the side of the vehicle away from the wind. G
WARNING
When the auxiliary heating is switched on,
parts of the vehicle can become very hot.
Flammable materials such as leaves, grass or twigs may ignite if they come into contact
with:
R hot parts of the exhaust system
R the exhaust gas itself
There is a risk of fire.
When the auxiliary heating is switched on,
make sure that:
R no flammable materials come into contact
with hot vehicle components
R the exhaust gas can escape from the
exhaust pipe unhindered
R the exhaust gas does not come into contact
with flammable materials.
! Operating the auxiliary heating/ventilation
draws on the vehicle battery. After you have
heated or ventilated the vehicle a maximum of two times, drive for a longer distance.
Only vehicles with auxiliary heating have this
function.
In the Heating Heating submenu, you can select a
stored departure time or change a departure
time.
The auxiliary heating timer function calculates
the switch-on time according to the outside
temperature so that the vehicle is preheated by the departure time. When the departure time isreached, the auxiliary heating continues to heat
for a further five minutes and then switches off. The auxiliary heating adopts the THERMATIC orTHERMOTRONIC temperature setting.
You can switch off the auxiliary heating by using
the remote control or the auxiliary heating but-
ton on the centre console.
i Switch the auxiliary heating on regularly
once a month for about ten minutes.
Further information on auxiliary heating
(Y page 132). 226
Menus and submenusOn-board computer and displays

Display messages
Possible causes/consequences and
M
MSolutions #
See Owner's Manual See Owner's Manual The battery is not being charged.
A warning tone also sounds.
Possible causes:
R faulty alternator
R torn poly-V-belt
R a malfunction in the electronics
! Do not continue driving. The engine could otherwise overheat.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
X Consult a qualified specialist workshop. #
Stop vehicle See Stop vehicle See
Owner's Manual Owner's Manual The battery is no longer being charged and the battery charge level is
too low.
A warning tone also sounds.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Safeguard the vehicle against rolling away (Y page 157).
X Observe the instructions in the #See SeeOwner's
Owner's Manual
Manualdisplay
message.
X Consult a qualified specialist workshop. 4
Check Check
eng.
eng.oil
oillev.
lev.
when
when next
nextrefuelling
refuelling The engine oil level has dropped to the minimum level.
A warning tone also sounds.
! Avoid long journeys when there is too little coolant in the cooling
system. Otherwise the engine will be damaged.
X Check the oil level when next refuelling, at the latest (Y page 291).
X If necessary, top up the engine oil (Y page 292).
X Have the engine checked at a qualified specialist workshop if the
engine oil needs topping up more often than usual.
Information on approved engine oils can be obtained from any quali-
fied specialist workshop or on the Internet at http://bevo.mercedes-
benz.com. 8
Reserve fuel level Reserve fuel level 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. C There is very little fuel in the fuel tank.
The auxiliary heating cannot be operated.
X Refuel at the nearest filling station without fail. Display
messages
239On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Risk of vehicle
Risk of vehicle
rolling rolling
Transmission Transmission
not
notin
in
P
P The driver's door is open or not fully closed and the transmission is in
position R,Nor D.
A warning tone also sounds.
G WARNING
The vehicle may roll away.
There is a risk of an accident.
X Shift the transmission to position P.
X Safeguard the vehicle against rolling away (Y page 157).
X Close the driver's door fully. Only
Only
select
select Park
Park(P)
(P)
when
when vehicle
vehicle is
issta‐
sta‐
tionary
tionary The vehicle is moving.
X
Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Shift the transmission to position P.Without changing Without changing
gear, gear,
consult workshop consult workshop You cannot change the transmission position due to a malfunction.
A warning tone also sounds.
If transmission position
Dis selected:
X Drive to a qualified specialist workshop without shifting the trans-
mission from position D.
If transmission position R,Nor Pis selected:
X Safeguard the vehicle against rolling away (Y page 157).
X Consult a qualified specialist workshop. Reversing not poss. Reversing not poss.
consult workshop consult workshop You cannot shift into the transmission position
Rdue to a malfunction.
The transmission positions P,N or Dcontinue to be available.
A warning tone also sounds.
X Consult a qualified specialist workshop. Transmission Mal‐
Transmission Mal‐
function Stop function Stop A malfunction has occurred in the mechanical transmission compo-
nents.
A warning tone also sounds. The transmission shifts automatically to position N.
X Pull over and stop the vehicle safely as soon as possible, paying
attention to road and traffic conditions.
X Shift the transmission to position P.
X Safeguard the vehicle against rolling away (Y page 157).
X Consult a qualified specialist workshop. Auxiliary battery Auxiliary battery
Malfunction
Malfunction The auxiliary battery for the transmission is no longer being charged.
X Consult a qualified specialist workshop at the next opportunity.
X Until then, set the transmission to position Pbefore you switch off
the engine.
X Before leaving the vehicle, apply the parking brake. Display
messages
249On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions j
Check Check
trailer
trailer hitch
hitch
lock
lock The trailer tow hitch is not correctly engaged.
A warning tone also sounds.
G WARNING
If the ball coupling is not engaged, the trailer may come loose. There
is a risk of an accident.
X Stop the vehicle immediately, paying attention to road and traffic
conditions, and switch off the engine.
X Apply the parking brake.
X Engage the trailer coupling's ball coupling in the end position
(Y page 210). &
inoperative inoperative
Battery
Battery
Low
Low The on-board voltage is too low. The auxiliary heating has switched
itself off or cannot be switched on (Y page 132).
X Drive for a considerable distance.
The battery charges. The auxiliary heating is operational again as
soon as the on-board electrical system voltage is sufficient. &
inoperative Refuel inoperative Refuel
vehicle vehicle There is too little fuel in the fuel tank. The auxiliary heating cannot be
switched on (Y page 132).
X Refuel at the nearest filling station. &
inoperative inoperative
See
SeeOwn‐
Own‐
er's Man.
er's Man. The auxiliary heating is temporarily malfunctioning or faulty.
X When the vehicle is on a level surface and the engine has cooled
down, make up to four attempts to switch on the auxiliary heating,
waiting several minutes between each attempt (Y page 132).
X If the auxiliary heating does not switch on, consult a qualified spe-
cialist workshop. Telephone Telephone
No
Noservice
service Your vehicle is outside the network provider's transmitter/receiver
range.
X Wait until the mobile phone operational readiness symbol appears
in the multifunction display. Ð
Power steering mal‐ Power steering mal‐
function See Own‐ function See Own‐
er's Manual er's Manual The power steering assistance is faulty.
A warning tone also sounds.
G WARNING
You will need to use more force to steer.
There is a risk of an accident.
X Check whether you are able to apply the extra force required.
X If you are able to steer safely: carefully drive on to a qualified
specialist workshop.
X If you are unable to steer safely: do not drive on. Contact the
nearest qualified specialist workshop. Display
messages
251On-board computer and displays Z

Display messages
Possible causes/consequences and
M
MSolutions Â
Change Change
key
keybatteries
batteries The battery of the KEYLESS-GO key is discharged.
X Change the replace (Y page 77).Â
Key not detected Key not detected
(red display message) The KEYLESS-GO key 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.
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 157).
X Locate the KEYLESS-GO key. A strong source of radio waves is causing interference, this means that
the KEYLESS-GO key is not recognised when the engine is running.
A warning tone also sounds.
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 157).
X Insert the key into the ignition lock and bring into key mode. Â
Key not detected Key not detected
(white display message) 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
Remove Remove
starting
starting but‐
but‐
ton,
ton, then
theninsert
insert key
key The KEYLESS-GO key is not continually detected.
KEYLESS-GO is temporarily malfunctioning or is defective. A warning tone also sounds.
X Insert the key into the ignition lock and turn it to the desired posi-
tion.
X Consult a qualified specialist workshop. Warning and indicator lamps in the instrument cluster
General notes
Some systems carry out a self-diagnosis when the ignition is switched on. Several warning and
indicator lamps can thereby temporarily light up or flash. This behaviour is non-critical. These
warning and indicator lamps only indicate a malfunction if they light up or flash after the engine is started or during a journey. Wa
rning and indi cator lamps in the instrument cluster
253On-board computer and displays Z

X
To open: pull cover ;out by its top edge.
X To remove the insert: press release button
= and lift the insert up and out.
X To fit the insert: fit insert:into the holder
from above and press down into the holder
until it engages. Cigarette lighter
Important safety notes G
WARNING
You can burn yourself if you touch the hot
heating element or the socket of the cigarette lighter.
In addition, flammable materials can ignite if:
R the hot cigarette lighter falls
R a child holds the hot cigarette lighter to
objects, for example
There is a risk of fire and injury.
Always hold the cigarette lighter by the knob.
Always make sure that the cigarette lighter is
out of reach of children. Never leave children unattended in the vehicle.
Your attention must always be focused on the
traffic conditions. Only use the cigarette lighter when road and traffic conditions permit.
Cigarette lighter in the front compart-
ment Example: vehicles with automatic transmission X
Turn the key to position 2in the ignition lock
(Y page 139).
X To open: slide cover :forwards until it
engages.
X Press in cigarette lighter ;.
Cigarette lighter ;will pop out automatically
when the heating element is red-hot.
X To close: briefly press cover :at the front.
The cover retracts. 12 V sockets
General notes X
Turn the key to position 1in the ignition lock
(Y page 139).
The sockets can be used for accessories with a
maximum draw of 180 W(15 A). Accessories
include such items as mobile phone chargers.
If you use the sockets for long periods when the engine is switched off, the battery may dis-
charge.
An emergency cut-off ensures that the on-boardvoltage does not drop too low. If the on-board
voltage is too low, the power to the sockets is
automatically cut. This ensures that there is suf-
ficient power to start the engine.
Socket in the front centre console Example: vehicles with automatic transmission
X To open: slide cover :forwards until it
engages.
X Lift up the cover of socket ;.
X To close: briefly press cover :at the front.
The cover retracts. 280
FeaturesStowing and fea
tures

Further information on windscreen washer
fluid/antifreeze (Y page 342).Service
ASSYST PLUS
Service messages The ASSYST PLUS service interval display
informs you of the next service due date.
Information on the type of service and service
intervals (see the separate Service Booklet).
You can obtain further information from a
Mercedes-Benz Service Centre.
i The ASSYST PLUS service interval display
does not show any information on the engine oil level. Observe the notes on the engine oil
level (Y page 291).
The multifunction display shows a service mes-
sage for a few seconds, e.g.:
R Service A in .. days Service A in .. days
R Service A overdue
Service A overdue
R Service A overdue by .. days
Service A overdue by .. days
Depending on the operating conditions of the
vehicle, the remaining time or distance until the next service due date is displayed.
The letter indicates which service is due. A A
stands for a minor service and B
Bfor a major ser-
vice. A number or another letter may be dis-
played after the letter.
Only for certain countries: the position after the
letter A
A or B Bindicates any necessary additional
maintenance work to be performed. If you notify a qualified specialist workshop of this display,
you will receive a statement on the associated
costs.
The ASSYST PLUS service interval display does
not take into account any periods of time during
which the battery is disconnected.
Maintaining the time-dependent service sched-
ule:
X Note down the service due date displayed in
the multifunction display before disconnect-
ing the battery.
or X After reconnecting the battery, subtract the
battery disconnection periods from the ser-
vice date shown on the display. Hiding service messages X
Press the aor% button on the steering
wheel.
Displaying service messages X
Switch the ignition on.
X Press the =or; button on the steering
wheel to select the Service Servicemenu.
X Press the 9or: button to select the
ASSYST
ASSYST PLUS
PLUSsubmenu and confirm by press-
ing the abutton.
The service due date appears in the multi-
function display.
Information about Service Resetting the ASSYST PLUS service inter-
val display
! If the ASSYST PLUS service interval display
has been inadvertently reset, this setting can
be corrected at a qualified specialist work-
shop.
Have service work carried out as described in
the Service Booklet. This may otherwise lead to increased wear and damage to the major
assemblies or the vehicle.
A qualified specialist workshop, e.g. a
Mercedes-Benz Service Centre, will reset the
ASSYST PLUS service interval display after the
service work has been carried out. You can also
obtain further information on maintenance
work, for example.
Special service requirements The prescribed service interval is based on nor-
mal operation of the vehicle. Service work will
need to be performed more often if the vehicle is operated under arduous conditions or increased
loads, for example:
R regular city driving with frequent intermediate
stops
R if the vehicle is primarily used to travel short
distances
R for frequent operation in mountainous terrain
or on poor road surfaces
R if the engine is often left idling for long periods
In these or similar operating conditions, have,
for example, the air filter, engine oil and oil filter changed more frequently. The tyres must be
checked more frequently if the vehicle is oper- 294
ServiceMaintenance and care