I used these instructions from NASIOC as I've been pouring over many threads on how to do it, but I cannot get the car to even enter programming mode. It is on my 2004 wrx w/ a turbo timer (which is turned off) and nothing else to speak of. I bought a used remote off of ebay which is identical to my stock one and the LED illuminates when I push the buttons. The car is not in valet mode.
I'll give it a shot, but I cannot even get the car to honk or chirp as it is supposed to when it is in programming mode.
Only reason for that, from what I've read extensively, is for the tear-drop style remotes that require you to enter the code for the controller via the lock/unlock button.
Took me about 25 times to get mine to work.And as far as I can tell I did it the same exact way every time.Just keep trying..