Subaru 2004 Impreza Owner's Manual page 115

Keys and doors
1) ON
2) LOCK
4. Place the ignition key into the ignition switch and
cycle the switch from LOCK to ON ten times within 15
seconds. Be sure to stop at the LOCK position. The
horn will sound once to indicate that you are in the
transmitter programming mode.
NOTE
You must finish the next step (opening the driver's
door) within 45 seconds of starting this proce-
dures.
2-12
1
2
To program the transmitters:
1
2
1. Open the driver's door.
2. Close the driver's door.
0