Receiver; Transmission Code - Mitsubishi Eclipse Technical Information Manual

Transmission switch

Transmission code

Data code
Cyclic code

RECEIVER

The receiver is mounted at the driver's side rear
quarter panel. The receiver has a code registration
switch by which the receiver is switched between
the system operation mode and code registration
mode.
Normal keyless entry system operations are per-
formed in the system operation mode. In the system
operation mode, the signals transmitted from the
transmitter are compared with the code stored in
the EEPROM in the receiver. Only when the results
are in agreement, a signal is output to the ETACS-
ECU to lock or unlock the doors and cause the
dome light to flash (when the doors are locked)
or steadily light (when the doors are unlocked). (The
dome light switch, however, must be in the "DOOR"
position.)
When the transmitter or receiver is replaced, note
that the secret code unique to the transmitter and
Code registration switch
Transmission Code
The illustration at left shows a code transmitted from the trans-
mitter. When the switch is operated once, three data codes
following the cyclic code are sent. One data code comprises
a total of 51 bits, of which 21 bits are used to constitute a
secret code for identification of the user, and the remaining
25 bits are used for system identification, etc. The secret code
for user identification is a combination of "OS" and "1s". More
than a million combinations are available.
the code stored in the EEPROM in the receiver
will be out of agreement. To allow operation of the
system, the code sent from the transmitter must
coincide with the code stored in the receiver. For
this purpose, place the receiver in the registration
mode and write (transmit) the secret code assigned
to the transmitter in the EEPROM in the receiver
as a new code.
The EEPROM can store two codes. Since the user
has only one transmitter at first, the EEPROM stores
two identical codes at shipment. When the user
wants to use one more transmitter, a maximum
of two transmitters can be used by repeating the
registration operation to the EEPROM.
(EEPROM: Electrical Erasable & Programmable
ROM which allows data to be electrically erased
and rewritten)
(L.H.)