2015 MERCEDES-BENZ E-CLASS CABRIOLET key battery

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

occupants from suffering acid burns should the
battery be damaged in the event of an accident.
In order for the battery to achieve the maximum possible service life, it must always be suffi-
ciently charged.
Like other batteries, the vehicle battery may
discharge over time if you do not use the vehicle. In such cases, have the battery disconnected ata qualified specialist workshop. You can also
charge the battery with a charger recommended
by Mercedes-Benz. For more information,
please contact a qualified specialist workshop.
Have the battery charge checked more fre-
quently if you use the vehicle mainly for short
trips or if you leave it standing idle for a lengthy period. Consult a qualified specialist workshop
if you wish to leave your vehicle parked up for a
long period of time.
When you park the vehicle, remove the key if you do not require any electrical consumers. The
vehicle will then use very little energy, thus con- serving battery power.
If the power supply has been interrupted, e.g. if the battery was discharged, you will have to:
R set the clock. Information on setting the clock
can be found in the Digital Owner's Manual.
On vehicles with a multimedia system, the
time is set automatically.
R reset the function for folding the exterior mir-
rors in/out automatically, by folding the mir-
rors out once (Y page 111). Charging the battery
G
WARNING
During charging and jump-starting, explosive
gases can escape from the battery. There is a risk of an explosion.
Particularly avoid fire, naked flames, creating
sparks and smoking. Ensure there is sufficient
ventilation while charging and jump-starting.
Do not lean over a battery. G
WARNING
Battery acid is caustic. There is a risk of injury. Avoid contact with the skin, eyes or clothing.
Do not breathe in any battery gases. Do not
lean over the battery. Keep the batteries out
of the reach of children. Immediately rinse off battery acid thoroughly with plenty of clean
water and seek medical attention at once. G
WARNING
A discharged battery can freeze at tempera-
tures below freezing point. When jump-start-
ing the vehicle or charging the battery, gases can escape from the battery. There is a risk of
an explosion.
Allow the frozen battery to thaw out before
charging it or jump-starting.
! Only use battery chargers with a maximum
charging voltage of 14.8 V.
! Only charge the battery using the jump-start
connection point.
The jump-starting connection point is in the
engine compartment (Y page 313).
X Open the bonnet.
X Connect the battery charger to the positive
terminal and earth point in the same order as
when connecting the donor battery in the
jump-starting procedure (Y page 313).
If the indicator/warning lamps do not light up at
low temperatures, it is very likely that the dis-
charged battery has frozen. In this case, you
may neither charge the battery nor jump-start
the vehicle. The service life of a battery that has been thawed may be reduced. The starting char-
acteristics may be impaired, especially at low
temperatures. Have the thawed battery
checked at a qualified specialist workshop.
Never charge a battery still installed in the vehi-
cle unless a battery charger unit approved by
Mercedes-Benz is being used. A battery charger unit specially adapted for Mercedes-Benz vehi-
cles and tested and approved by Mercedes-
Benz is available as an accessory. This device
permits charging of the battery in position. Con-
tact a Mercedes-Benz Service Centre for infor-
mation and availability. Read the battery charg- er's operating instructions before charging the
battery. 312
Battery (vehicle)Breakdown assistance

Do not use a rapid charging device to start the vehicle. If your vehicle's battery is discharged, the
engine can be jump-started from another vehicle or from a second battery using jump leads.
Observe the following points:
R The battery is not accessible in all vehicles. If the other vehicle's battery is not accessible, jump-
start the vehicle using a second battery or a jump-starting device.
R Vehicles with a petrol engine: only jump-start the vehicle when the engine and exhaust system
are cold.
R Jump-starting may only be performed using batteries with a nominal voltage of 12 V.
R Only use jump leads that have a sufficient cross-section and insulated terminal clamps.
R If the battery is fully discharged, leave the battery that is being used to jump-start connected for
a few minutes before attempting to start. This charges the empty battery a little.
R Make sure that the two vehicles do not touch.
Make sure that:
R The jump leads are not damaged.
R Non-insulated parts of the terminal clamps do not come into contact with other metal parts while
the jump leads are connected to the battery.
R The jump leads cannot come into contact with parts which can move when the engine is running,
such as the V-belt pulley or the fan.
X Firmly depress the parking brake.
X Manual transmission: depress the clutch pedal fully and shift to neutral.
X Automatic transmission: shift the transmission to position P.
X Make sure the ignition is switched off. All indicator lamps in the instrument cluster must be off.
When using the key, turn the key to position 0in the ignition lock and remove it (Y page 139).
X Switch off all electrical consumers, e.g. rear window heating, lighting etc.
X Open the bonnet. Position number
Bidentifies the charged battery of the other vehicle or an equivalent jump-starting
device. 314
Jump-startingBreakdown assistance

R
Observe the brake lamps of the towing
vehicle while driving. Always maintain a dis-
tance a distance so that the tow rope does not sag.
R Do not use steel cables or chains to tow
your vehicle. You could otherwise damage
the vehicle.
! Do not use the towing eye for recovery, this
could damage the vehicle. If in doubt, recover
the vehicle with a crane.
! Pull away smoothly when towing away or
tow-starting a vehicle. If the tractive power is
too high, the vehicles could be damaged.
! On vehicles with KEYLESS-GO, use the key
instead of the Start/Stop button. Turn the key
to position 2in the ignition lock and shift the
automatic transmission to N. Then, turn the
key back to 0and leave it in the ignition lock.
! You may tow the vehicle for a maximum of
50km. A towing speed of 50 km/h must not
be exceeded.
For towing distances over 50 km, the entire
vehicle must be lifted up and transported.
! If you tow or tow-start another vehicle, its
weight must not exceed the maximum per-
missible gross vehicle weight of your vehicle.
Observe the legal requirements for the relevant
countries when towing and tow-starting.
It is better to have the vehicle transported than
to have it towed.
If the vehicle has suffered transmission damage, have it transported on a transporter or trailer.
When towing away a vehicle with an automatic
transmission, the transmission must be in posi-
tion N.
The battery must be connected and charged.
Otherwise, you:
R cannot turn the key to position 2in the igni-
tion lock
R cannot shift the transmission to position Non
vehicles with automatic transmission
In the event of damage to the electrical sys-
tem
If the battery is defective, the automatic trans-
mission will be locked in position P. To shift the
automatic transmission to position N, you must
provide power to the vehicle's on-board electri- cal system in the same way as when jump-start-
ing (Y page 313). Have the vehicle transported on a transporter or
trailer.
Deactivate the automatic locking feature beforetowing the vehicle (Y page 82). You could oth-
erwise be locked out when pushing or towing
the vehicle.
Deactivate tow-away protection before the vehi- cle is towed away (Y page 72). Fitting/removing the towing eye
Fitting the towing eye G
WARNING
The exhaust tail pipe may be extremely hot.
There is a risk of burning when removing the
rear cover.
Do not touch the exhaust tail pipe. Use
extreme caution when removing the rear
cover. The mountings for the removable towing eyes
are located in the bumpers. They are at the rear
and at the front, under covers :.
X Remove the towing eye from the vehicle tool
kit (Y page 305).
X Press the mark on cover :inwards in the
direction of the arrow. 316
Towing away and tow-startingBreakdown assistance

X
Vehicles with manual transmission:
depress the clutch pedal fully and engage
neutral.
X Vehicles with automatic transmission:
turn the key to position
2in the ignition lock.
X Shift the automatic transmission to position
N.
As soon as the vehicle is loaded: X Prevent the vehicle from rolling away by
applying the parking brake.
X Vehicles with manual transmission:
depress the clutch pedal fully and engage first
or reverse gear.
X Vehicles with automatic transmission:
shift the automatic transmission to position
P.
X Turn the key to position 0in the ignition lock
and remove it.
X Secure the vehicle. Tow-starting (emergency engine
starting)
! Vehicles with automatic transmission must
not be tow-started. The transmission may
otherwise be damaged.
i You can find information on "Jump-starting"
under (Y page 313).
Before tow-starting, the following conditions
must be fulfilled:
R the battery is connected
R the engine has cooled down
R the exhaust system has cooled down
When tow-starting, it is important that you
observe the safety notes (Y page 315) and the
legal requirements in each respective country.
X Switch on the hazard warning lamps
(Y page 116).
X Fit the towing eye (Y page 316).
X Secure the rigid towing bar or the towing
rope.
X Depress the brake pedal and keep it
depressed.
X Turn the key to position 2in the ignition lock.
X Depress the clutch pedal fully, engage second
gear and continue to keep the clutch pedal
fully depressed.
X Release the brake pedal. X
Tow-start the vehicle.
X Release the clutch pedal slowly, do not
depress the accelerator pedal while doing so.
X When the engine has been started, immedi-
ately depress the clutch pedal fully and shift
to neutral.
X Pull over at a suitable place and stop the vehi-
cle safely, paying attention to road and traffic
conditions.
X Depress the parking brake.
X Remove the rigid towing bar or towing rope.
X Remove the towing eye (Y page 317).
X Switch off the hazard warning lamps. Electrical fuses
Important safety notes
G
WARNING
If you manipulate, bridge or replace a faulty
fuse with a fuse of a higher amperage, the
electric cables could be overloaded. This may result in a fire. There is a risk of an accident
and injury.
Always replace faulty fuses with specified new fuses of the correct amperage.
Blown fuses must be replaced with fuses of the same rating, which you can recognise by the
colour and fuse rating. The fuse ratings are listed
in the fuse allocation chart.
The fuse allocation chart is located in the vehicle tool kit in the stowage compartment under the
boot floor (Y page 305).
If the newly inserted fuse also blows, have the
cause traced and rectified at a qualified special- ist workshop, e.g. a Mercedes-Benz Service
Centre.
! Only use fuses that have been approved for
Mercedes-Benz vehicles and which have the
correct fuse rating for the system concerned.
Otherwise, components or systems could be
damaged.
! 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 seep-
ing in or dirt could otherwise impair the oper- ation of the fuses. 318
Electrical fusesBreakdown assistance