Subaru 2003 Impreza - Manual (Page 103)

IMPREZA(NA) A1850BE-A (ENGLISH)
Keys and doors
2-12
To program the transmitters:
1. Open the driver’s door.
2. Close the driver’s door.
1) Press any button.
3. Press and release any button on the transmitter
that you wish to program into the system. The horn
will sound two times to indicate that the transmitter
has been programmed.
Any additional transmitters can also be programmed
at this time. Repeat steps 1 through 3 for an addi-
tional transmitter.
To exit the programming mode:
1. After all of your transmitters are programmed, re-
move the key from the ignition switch.
The horn will sound three times to indicate that the
system has exited the programming mode.