Just bought used 2012 plugin, need to get an extra key.

congrats and welcome! no idea. if someone can't give you good advice, try reading through the many confusing threads here. all the best!

 

This has been discussed in many threads. The cheapest option is to buy a new "virgin" FOB on Ebay and also a miniVCI cable with the TechStream software. A virgin FOB just means it hasn't been paired with a car yet. Used FOBs cannot be programmed by yourself and requires a locksmith that has a subscription to Toyota's system that allows used keys to be reprogrammed (expensive).

Load Techstream on a laptop, plug the miniVCI device into your OBDII port and your lapop, and follow the pairing instructions for a new FOB. You will also need to get the mechanical key cut to match your existing one. I believe any locksmith should easily be able to do this.

The thread below has the details on this subject, including how to use Techstream.

Smart Key Replacement Cost | PriusChat

 

I am going through this now. Just like you I bought a used prius with 1 key. I found a used key locally on offer up for $25 and took it to the dealer to program to car. My local dealer will program a key for free so they tried and was not able to program.

I found a guy on ebay that will reset the fob so it can be programmed and he gives you a new key to be cut. He only charges like $15 for his services. I sent him my fob Monday and should have it back tomorrow. When I get a chance I well take it in to get programmed and will let you know how it worked.

 

So I finally made it over to the dealer to have the remote I sent in programmed. They were able to program it and it work's flawlessly. Now I feel better having 2 key fobs.

The cost was definitely worth it. If you need another key fob and have one from another toyota or even some lexus, he can make them like new again.

The seller was ezautoremote.
Hope this helps someone.

 

How much did the dealership charge to program it? I assume that whatever was done to the fob to allow it to be paired to the car would also work for using TechStream to pair the fob.

 

The dealer didn't charge me anything but it depends on which service writer I talked to. When I took the fob in after buying it and it was still paired with another car, the service writer unsucessfully tried and it was free. Then after getting it back from ebay, when I went in they wanted to charge me half an hour labor.... I said no, I will come back when the other service writer returns. I went back when he was there and he was able to do it for free.

It depends on the service writer, the one that did it for free seemed like he knew his way around the computer pretty good for a service writer.

I am not familiar with tech steam so I can't answer that. I know by watching him and talking to him while he does it, he mentioned that when they plug in the computer to the obd2 port, there is a few, like 5, extra steps that happens on a PiP vs. a regular prius. He said the computer does a couple checks on the car, collects data from the car and sends it back to toyota? He said a regular prius doesn't take as long.