change key battery MERCEDES-BENZ C240 2001 W203 Owner's Manual

27 Central locking system
Te ch n i c a l
data Instruments
and controlsOperationDrivingInstrument
cluster displayPractical hints Car care Index Locking and unlocking with remote control
Unlocking:
Press transmit button Œ. All turn signal lamps blink
once to indicate that the vehicle is unlocked.
The remote control can be programmed for two kinds of
unlocking modes (see below):
Selective unlocking mode –
Press transmit button Œ once to unlock driver’s door
and fuel filler flap.
Press transmit button Πtwice to unlock all doors,
fuel filler flap, and trunk.
Global unlocking mode –
Press transmit button Πonce to unlock all doors,
fuel filler flap, and trunk.
Notes:
If the trunk was previously locked separately, it will
remain locked, see page 35.
The presently active unlocking mode (selective or
global) can only be determined by unlocking the vehicle
with the remote control (see below for changing mode).If within 40 seconds of unlocking with the remote
control, neither door or trunk is opened, the electronic
key is not inserted in the starter switch, or the central
locking switch is not activated, the vehicle will
automatically lock.
Locking:
Press transmit button ‹ once. All turn signal lamps
blink three times to indicate that the vehicle is locked. If
they do not blink three times, a door or trunk is not
properly closed.
Note:
If the vehicle cannot be locked or unlocked by pressing
the transmit button, then it may be necessary to change
the batteries in the electronic main key (if ok, battery
check lamp in electronic main key will light briefly
when pressing transmit button) or to synchronize the
remote control, see pages 332 and 334.
Choosing global or selective mode on remote control
Press and hold transmit buttons‹ andŒ
simultaneously for five seconds to reprogram the
remote control. Battery check lamp will blink two times
indicating the completed mode change.

332 Electronic main key
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index
Changing batteries in the electronic main key
1Transmit buttons
2Lamp for battery check and function control
Checking batteries
If one of the transmit buttons (1) is pressed, the battery
check lamp (2) lights up briefly – indicating that the
batteries are in order.
Change batteries if the battery check lamp (2) does not
light up briefly.Changing batteries
Move locking tab (3) in direction of right arrow and
remove mechanical key (4, left arrow).
P80.20-2201-26
1
2
P80.35-2029-26
4
3

333 Electronic main key
Te ch n i c a l
data Instruments
and controlsOperation DrivingInstrument
cluster displayPractical hintsCar care Index Insert mechanical key (4) in side opening (5) to open
latch. Press briefly (do not use mechanical key as lever)
to release battery compartment.
Remove mechanical key from side opening.
Carefully remove battery compartment in direction of
arrow (6).Change batteries (7), inserting new ones under contact
spring (8) with plus (+) side facing up.
Return battery compartment into housing until locked
in place and slide mechanical key back into electronic
main key.
P80.35-2025-26
5
4
6
P80.35-2027-26
78