Inexpensive Key/Fob

I think it was just a key for gen 1 Prius: Spare Key Options | PriusChat

Lots of different keys would actually work as all it needs is the same type of immobilizer chip. But you should find one that can be cut to match the door look so you can get in as well.

But remember that this key can’t be used to program in new keys. So you should still have two key fobs in case you lost one.

 

I have such a key, but it's hardly a standard item.

Gen2 keyfobs have a transponder chip in them as well as a circuit board. The transponder chip is the same design as is used in chip keys used in earlier designs.

What I did was get a Toyota chip key (Gen1 key will do), carefully open the head and remove the chip. Then replace the chip with one extracted from a Gen2 keyfob.

The end result is a key that can open the door with the mechanical blade. Inserting the key head first into the keyslot unlocks the ignition. Once you press the Power button, the key can be removed from the keyslot (it doesn't lock in like a real keyfob). When you turn the car off, you have to release the keyslot locking mechanism (sticking your finger in works fine).

I keep the modified key inside the car for use if I lose the real keyfob. Even if a thief found it, they wouldn't have a clue how to use it to start the car.

 

I remember a locksmith who figured out how to get the proper transponder without having to take it out of a keyfob. So the price would be something like $35 or so. He sold the keys on eBay. I've certainly lost track of him but you might find an eBay listing if you have the time.

 

Same type of immobilizer chip is already installed in some keys. So all it takes is to know what keys have the correct type of immobilizer chip and then just program that chip to the car and cut the key part to match the door lock.

RobH you just couldn’t program in the gen1 key with chicken dance method? I would have thought the immobilizer chips in gen2 and gen1 key would be the same.

 

The proper locksmith equipment could identify the transponder used, or maybe there is some reference document that already has that data. Not having that equipment, I just tried a Gen1 key. Didn't work. But the transponder inside the keyfob looks exactly like the one inside the Gen1 key.