I got a used 2004 Prius with one key. I got two more keys from eBay, did the chicken dance, got the new fobs locking/unlocking doors, but not starting the car. When I got to the start (from slot) programming part of the chicken dance, the light would flash twice, then three times. In one of the forum threads on key programming, someone mentioned that the 2-3 code means all slots are full. I got one of the ~$20-ish Mini VCI cables that comes with Techstream, did the electronic chicken dance and wiped all keys except for the master key I had, then programmed the two additional keys.
I have reached the limit of fobs programmed in my 2005 Prius. We have lost three fobs over the years. I need to program another fob. Is there a way to erase old fobs without going to the dealer?
Yes: one of the chicken dances you can find in the repair manual should be the "forget every fob you ever knew except this one I'm using in the dance" dance. -Chap