Key fob question

I'm the second owner of a 2008 prius. When I bought it, the seller had misplaced the second key, so I got only one key.

When my key went missing in 2011, it cost me dearly. I bought two new keys directly from a dealer for a total $327 (over the internet - much cheaper than buying from the local Toyota dealer) and then paid the dealer another $223 to program them.

Of course, the original key was found 3 days later, underneath the refrigerator...

Question 1. Could someone tell me if it's possible to reprogram the old key even though the dealer programmed the two new keys? I know there are forum threads about how to do the reprogram - I'm just not sure if it's (a) possible to make the old key work after what the dealer did, and (b) which of the various key programming t hreads is the corect one for this situation. as I recall, the car did not have to be towed to the dealer Correction: the car had to be towed to the dealer along with the two new keys to be "programmed"

Question 2. A few weeks ago our key fob stopped allowing us to unlock the driver door just by pulling on the handle (it is now necessary to press the unlock button on the key fob). At the same time we noticed the car will not start unless the key fob is inserted into the dashboard. Up until this point, it was possible to (a) unlock the door by just pulling on the handle, and (b) start the car while leaving the key fob in one's pocket.

I thought it might be a low battery in the fob we use daily, so I got the spare one (also bought new in 2011) out of the drawer and tried it. Same behavior,

Does this situation indicate a low battery in the fob, a need for a new 12 volt battery in the car, or something else? Could someone point me to an existing thread that answers this question?

Thank you!

 

I've replaced the CR2032 batteries in all three key fobs (the original one, and also the two that were programmed at the dealer.)

- the two new ones will lock and unlock the door only by pressing the unlock button on the fob (not just by pulling on the door handle, which used to work). They will start the car only if they are inserted in the slot in the dashboard (not just by being in my pocket, as used to work.) I had hoped that replacing the fob battery would solve this. What is the next step to restore that function?

- the old key does not have any effect on the car, despite its new battery. Did the dealer have to unlink the old key in order to link the two new ones? If not, should there be a policy saying they shouldn't have unlinked the old key since I did not ask them to?