2005 MERCEDES-BENZ C320 key battery

95 Controls in detail
Locking and unlocking
Trunk lid emergency release
The emergency release button is located
on the inside of the trunk lid.
1Emergency release button
Briefly press emergency release
button1.
The trunk lid unlocks and the trunk lid
opens.Illumination of the emergency release
button:


The button will flash for 30 minutes
after opening the trunk.


The button will flash for 60 minutes
after closing the trunk.
!The trunk lid swings open upwards
automatically.
iThe emergency release button unlocks
and opens the trunk while the vehicle is
standing still or in motion.iThe emergency release button does
not open the trunk lid if the vehicle
battery is discharged or disconnected.
iIf the vehicle has previously been
locked from the outside with the
SmartKey, opening the trunk from the
inside using the emergency release
button will trigger the anti-theft alarm
system*.
To cancel the alarm, do one of the
following:

Press buttonŒ or‹ on the
SmartKey.


Insert the SmartKey in the starter
switch.

301 Practical hints
What to do if …
Where will I find ...?
Unlocking/locking in an emergency
Opening/closing in an emergency
Replacing SmartKey batteries
Replacing bulbs
Replacing wiper blades
Flat tire
Battery
Jump starting
Towing the vehicle
Fuses

342 Practical hintsReplacing SmartKey batteriesIf the batteries in the SmartKey are
discharged, the vehicle can no longer be
locked or unlocked. It is recommended to
have the batteries replaced at an
authorized Mercedes-Benz Center.Batteries contain materials that can harm
the environment if disposed of improperly.
Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.Warning!
G
Keep the batteries out of reach of children.
If a battery is swallowed, seek medical help
immediately.
iWhen inserting the batteries, make
sure they are clean and free of lint.iWhen replacing batteries, always
replace both batteries.
The required replacement batteries are
available at any Mercedes-Benz
Center.

343 Practical hints
Replacing SmartKey batteries
SmartKey
Replacement batteries: Lithium, type
CR 2025 or equivalent.
Remove the mechanical key
(page 337).
1Mechanical key
2Battery compartment

Insert mechanical key1 in side
opening and push grey slide.
Battery compartment2 is unlatched.

Pull battery compartment2 out of the
housing in direction of arrow.

Remove the batteries.
3Battery
4Contact spring

Using a lint-free cloth, insert new
batteries3 under contact spring4
with the plus (+) side facing up.

Return battery compartment2 into
housing until it locks into place.

Slide mechanical key1 back into the
SmartKey.

Check the operation of the SmartKey.

360 Practical hintsBatteryThe battery is located in the engine
compartment on the right hand side.
1Clamps
Removing filter box:
Release clamps1.

Remove filter box.
Installing filter box:

Insert filter box properly.

Secure it with clamps1.
Warning!
G
Failure to follow these instructions can
result in severe injury or death.
Observe all safety instructions and
precautions when handling automotive
batteries (
page 284).
Never lean over batteries while connecting,
you might get injured.
Battery fluid contains sulfuric acid. Do not
allow this fluid to come in contact with eyes,
skin or clothing. In case it does, immediately
flush affected area with water and seek
medical help if necessary.
A battery will also produce hydrogen gas,
which is flammable and explosive. Keep
flames or sparks away from battery, avoid
improper connection of jumper cables,
smoking, etc.
!Never loosen or detach battery termi-
nal clamps while the engine is running
or the SmartKey is in the starter switch.
Otherwise the alternator and other
electronic components could be se-
verely damaged.
Have the battery checked regularly by
an authorized Mercedes-Benz Center.
Refer to Maintenance Booklet for
maintenance intervals or contact an
authorized Mercedes-Benz Center for
further information.Warning!
G
Do not place metal objects on the battery as
this could result in a short circuit.
Use leak-proof battery only to avoid the risk
of acid burns in the event of an accident.

361 Practical hints
Battery
1Negative terminal
2Positive terminal cover
Disconnecting the battery
Turn off the engine (
page 56).

Turn off all electrical consumers.

Remove SmartKey from starter switch.

Open the hood (
page 278).

Remove the filter box (
page 360).

Disconnect the battery negative lead
from negative terminal1.

Remove cover2 from the positive
terminal.

Disconnect the battery positive lead.
Removing the battery
Remove the screw-nuts securing the
battery.

Remove the battery bracket.

Take out the battery.
Charging and reinstalling the battery
Charge battery in accordance with the
instructions of the battery charger
manufacturer.

Reinstall the charged battery. Follow
the previously described steps in
reverse order.
Warning!
G
With a disconnected battery

you will no longer be able to turn the
SmartKey in the starter switch


the gear selector lever will remain
locked in positionP
Warning!
G
Never charge a battery while still installed in
the vehicle. Gases may escape during charg-
ing and cause explosions that may result in
paint damage, corrosion or personal injury.

362 Practical hintsBatteryReconnecting the battery
Turn off all electrical consumers.

Remove SmartKey from starter switch.

Connect the battery positive lead and
fasten its cover2.

Connect the battery negative lead.

Reinstall the filter box (
page 360).Batteries contain materials that can harm
the environment if disposed of improperly.
Large 12 volt storage batteries contain
lead. Recycling of batteries is the preferred
method of disposal. Many states require
sellers of batteries to accept old batteries
for recycling.
!NEVER invert the terminal connections!!The battery, its filler caps and the vent
tube must always be securely installed
when the vehicle is in operation.
iThe following procedures must be
carried out following any interruption of
battery power (e.g. due to reconnec-
tion):

Set the clock (
page 137).
Vehicles with COMAND*:
See COMAND operator’s manual.


Synchronize side windows
(page 226).


Synchronize tilt/sliding sunroof*
(page 230).

367 Practical hints
Towing the vehicle
Warning!
G
With the engine not running, there is no
power assistance for the brake and steering
systems. In this case, it is important to keep
in mind that a considerably higher degree of
effort is necessary to brake and steer the ve-
hicle. Adapt your driving accordingly.
!When towing the vehicle with all wheels
on the ground, please note the
following:
With the automatic central locking
activated and the SmartKey in starter
switch position2, the vehicle doors
lock if the left front wheel as well as the
right rear wheel are turning at vehicle
speeds of approx. 9 mph (15 km/h) or
more.
Switch off the tow-away alarm*
(page 85).
To prevent the vehicle doors from
locking, deactivate the automatic
central locking (
page 145).
Towing of the vehicle should only be
done using the properly installed
towing eye bolt. Never attach tow
cable, tow rope or tow rod to vehicle
chassis, frame or suspension parts.
iIf the battery is disconnected or
discharged

the SmartKey will not turn in the
starter switch. For more informa-
tion, see “Battery” (
page 360)
and “Jump starting” (page 363).


the gear selector lever will remain
locked in positionP. For informa-
tion on manually unlocking the
transmission gear selector lever
see (
page 340).