I'm new to this forum...what took me so long? I'm the original owner of a 2004 Prius. I had two keys. One has part of the top missing and is pretty thrashed from dropping it over the years and it's protected by some electrical tape, but it still works. The other even after replacing the battery still doesn't work. All I wanted to do was get a replacement key for that one using the thrashed one as a backup, but the dealer told me the car would have to be re-programmed for about $150 and each new key would cost $250 of course making my thrashed one useless because of the re-programming. in other words, for two new keys and the rest: about $650! Is there any other way around this without having to be a master tech guy? George
If the thrashed one is fully functional (the lock button works), then you can self program a new key with it. Just buy a new key online and DIY
Here's the thread you want to follow: How to Program a New Key Fob for Full SKS Functionality | PriusChat
In addition to the tips regarding a new key you can also replace the case of the working key very cheaply and it's easy to do. I recently replaced both of our cases for $9.99 each with the USARemote fits Toyota Prius Key Fob Cover Case from Amazon. Make sure you transfer three things from your old, taped case to the new one. 1. The circuit board 2. The little black RFID chip 3. The metal mechanical key.
What dealer told you your trashed key would be worthless due to reprogramming? Either they are lying crooks or incompetent. A gen 2 Prius can use up to 5 keys before anything would need to be done. Read this thread, you can do it yourself. How to Program a New Key Fob for Full SKS Functionality | PriusChat
and don't forget the RFID chip in the front of the bottom half. It is also possible to buy just an empty case (with or without the key blank) from the dealer if you want to just replace your case. Then there are all the cheap Chinese knock-offs all over the internet.