I have a series II 2008 Toyota Prius. I purchased a second key off of eBay and would like to program it for ignition and remote control.
I found these instructions on a forum. After several tries, I was able to get both the ignition and keyless entry to work.
Make sure you have on your original key and have looked on the back for a black toyota logo. This WILL NOT work for the smart keys with the SILVER toyota logo.
(Yes it Does for a 2009 Prius. Also BIG Thing: Have only the old remote and new or USED remote in the car. No Cell or Phone or Blue Tooth)
Now for the door lock functions.
The Fob (for remotely unlocking/locking the doors)
There is a difference between an "OEM" new never programmed FOB and on that has already been linked to a vehicle. That being said there is hope if you have gotten one off EBay that was used. The directions to program the ability to start the car work fine on either the OEM or the used FOB but the smart key (SKS) functions will not program with the open-close-door dance on a used FOB. All 4 of the Toyota dealers that I called told me there was nothing I could do and offered to sell me a new FOB and program it for prices ranging from $230-$290.