will a generation 2 prius key work on a generation 3 prius?

I think the fobs are not interchangeable between gen 2 and gen 3.

You can get used fobs for not much money, but beware: if a fob already thinks it has been registered to one car, you can't register it to some other car. You can search for "re-virginized" fobs, usually costing a little bit more than straight used ones, but it's worth it, because you can use them.

Or you can search up re-virginizing services online, get your hands on any old used fob, send it to them and get one back you can use. Probably end up spending about the same money as buying a re-virginized fob.

Beats me why the fobs even have that one-car restriction. If I had a multi-car family, it might be convenient to just have one collection of fobs and register them to all the cars.

(I guess it would suck if somebody got hold of one fob and came back and took the rest of the cars.)

 

If you are not the original owner and you do not know the history, then you also need to be concerned about the maximum number of fobs that can be linked to one vehicle. Once you hit that maximum, additional fobs cannot be linked without jumping through a bunch of hoops.

 

There's another reason to worry about that besides just running out of registration slots.

That's why it's smart to begin with the "forget all registered fobs except this one" function.

 

After the dealer spent two hours trying to link a additional fob to the car and came to the waiting area and told me it couldn't be done, I informed them of that workaround.

Unfortunately, they did not give me a discount for schooling their tech.

 

I kind of like doing the "forget all registered fobs except this one" thing my own personal self. Sort of the way I change the locks on a new place.