2004 MERCEDES-BENZ C320 Vent flap

82 Controls in detailLocking and unlocking
In the “Controls in detail” section you will
find detailed information on how to oper-
ate the equipment installed on your vehi-
cle. If you are already familiar with the
basic functions of your vehicle, this section
will be of particular interest to you.
To quickly familiarize yourself with the ba-
sic functions of the vehicle, refer to the
“Getting started” section of this manual.
The corresponding page numbers are giv-
en at the beginning of each segment.
Locking and unlocking
SmartKey
Your vehicle comes supplied with two
SmartKeys, each with remote control and
a removable mechanical key. The locking
tabs for the mechanical key portion of the
two SmartKeys are a different color to help
distinguish each SmartKey unit.
The SmartKey provides an extended oper-
ating range. To prevent theft, however, it is
advisable to only unlock the vehicle when
you are in close proximity to it.
The SmartKey centrally locks and unlocks:

the doors


the trunk


the fuel filler flap
SmartKey with remote control1‹ Lock button
2Š Opening button for the trunk lid
3Mechanical key locking tab
4ΠUnlock button
5Battery check lamp
6Â Panic button* (
page 71).
iYou can also open and close the power
windows (
page 202) and
sliding/pop-up roof* (
page 204)
from outside using the SmartKey.
iCanada only:
Only vehicles equipped with an
anti-theft alarm system* have
SmartKeys with integrated panic
button*6.

83 Controls in detail
Locking and unlocking
Factory setting
Global unlocking
Press buttonŒ.
All turn signal lamps flash once. The
locking knobs in the doors move up.
The vehicle will lock again automatically
within approximately 40 seconds of
unlocking if:


neither door nor trunk is opened


the SmartKey is not inserted in the
starter switch


the central locking switch is not
activatedGlobal locking

Press button‹.
All turn signal lamps flash three times.
The locking knobs in the doors move
down.
Selective setting
If you frequently travel alone, you may wish
to reprogram the SmartKey so that
pressingŒ only unlocks the driver’s
door and the fuel filler flap.

Press and hold buttonsŒ and‹
simultaneously for about five seconds
until battery check lamp5 flashes
twice.
The SmartKey will then function as
follows:
Unlocking driver’s door and fuel filler
flap
Press buttonΠonce.Global unlocking

Press buttonΠtwice.
Global locking

Press button‹.
Restoring to factory setting

Press and hold buttonsŒ and‹
simultaneously for about six seconds
until battery check lamp5 flashes
twice.
!To prevent possible malfunction, avoid
exposing the SmartKey to high levels of
electromagnetic radiation.
Warning!
G
When leaving the vehicle, always remove the
SmartKey from the starter switch, take it
with you and lock the vehicle. Do not leave
children unattended in the vehicle, or with
access to an unlocked vehicle. It is possible
for children to open a locked door from the
inside, which could result in an accident
and/or serious injury.

212 Controls in detailLoadingRemoving the ski sack
You can remove the ski sack for cleaning
or drying.
1Button
2Ski sack frame
3Flap
Open trunk lid.

Press button1.
The flap3 opens downward.

Press button1 firmly until ski sack
frame2 is released.

Pull ski sack frame2 with ski sack
out.Installing the ski sack
Install the ski sack in the reverse order.

Push ski sack frame2 with ski sack
inward until the ski sack frame snaps
into place.

Close flap3.

Close trunk lid.
Split rear bench seat*
To expand the cargo area, you can fold
down the left and right rear seat backrests.
The two sections can be folded down
separately.
Warning!
G
Never drive vehicle with trunk open while
the ski sack is removed. Deadly carbon
monoxide (CO) gases may enter vehicle in-
terior, resulting in unconsciousness and
death.iTo prevent unauthorized persons from
accessing the trunk, always close the
flap.
Warning!
G
When expanding the luggage area, always
fold the seat cushions fully forward.
Unless you are transporting cargo, the
backrests must remain properly locked in
the upright position.
In an accident, during hard braking or
sudden maneuvers, loose items will be
thrown around inside the vehicle, and cause
injury to vehicle occupants unless the items
are securely fastened in the vehicle.

250 OperationAt the gas station
Open fuel filler flap by pushing at the
point indicated by the arrow.
The fuel filler flap springs open.

Turn fuel cap to the left and hold on to
it until possible pressure is released.

Take off cap and set it in the recess on
fuel filler flap.
To prevent fuel vapors from escaping
into open air, fully insert filler nozzle
unit.

Only fill your tank until the filler nozzle
unit cuts out – do not top up or overfill.

Replace fuel cap by turning it to the
right.
You will hear when fuel cap is
tightened.

Close fuel filler flap.Warning!
G
Overfilling of the fuel tank may create
pressure in the system which could cause a
gas discharge. This could cause the gas to
spray back out when removing the fuel
pump nozzle, which could cause personal
injury.
iOnly use premium unleaded gasoline
with a minimum Posted Octane Rating
of 91 (average of 96 RON/86 MON).
Information on gasoline quality can
normally be found on the fuel pump.
More information on gasoline can be
found in the Factory Approved Service
Products pamphlet.
Flexible Fuel Vehicles are identified by
a label reading Premium gasoline or
E85 only! on fuel filler flap.
For more information, see “Flexible
Fuel Vehicles” (
page 354).
iLeaving the engine running and the fuel
cap open can cause the? malfunc-
tion indicator lamp to illuminate.
For more information, see “Practical
hints” (
page 276).


354 Technical dataFuels, coolants, lubricants, etc.Gasoline additives
A major concern among engine
manufacturers is carbon build-up caused
by gasoline. Mercedes-Benz recommends
only the use of quality gasoline containing
additives that prevent the build up of
carbon deposits.
After an extended period of using fuels
without such additives, carbon deposits
can build up especially on the intake valves
and in the combustion area, leading to
engine performance problems such as:

Warm-up hesitation


Unstable idle


Knocking/pinging


Misfire


Power loss
Do not blend any specific fuel additives
with fuel. This only results in unnecessary
cost and may be harmful to engine
operation.Damage or malfunctions resulting from
poor fuel quality or from blending specific
fuel additives are not covered by the
Mercedes-Benz Limited Warranty.
Flexible Fuel Vehicles
Flexible Fuel Vehicles are identified by a
label reading Premium gasoline or E85
only! on fuel filler flap.
These vehicles are designed to operate on
premium unleaded gasoline or Ethanol
fuel (E85), or on any mixture of these two.
Ethanol fuel (E85) is a mixture of
approximately 85% Ethanol and 15%
unleaded gasoline.Switching fuels
For best performance and driveability it is
recommended to use either one or the
other fuel. A refueling pattern that
alternates between the two different fuels
should be avoided if possible.
Warning!
G
Ethanol fuel (E85) and its fumes are highly
flammable, poisonous and burn easily. Etha-
nol fuel can cause serious injuries if ignited
or if you come into contact with it or inhale
fumes of it. Avoid inhalation of Ethanol
fumes and skin contact with Ethanol. Extin-
guish all open flames before fueling. Never
smoke or create sparks close to Ethanol.