When we purchased S.N. it came with one transponder key and one remote, both of which worked great but there was no backup. I called the dealer and it was going to cost $375 to have one additional key and remote made—a price I felt was way too high. Lowe’s was going to charge $75 just for one transponder key. I was able to get a key cut that didn’t have the chip, which allows the car doors to be opened, but doesn’t start the engine.
After some research I discovered that for many models of cars a blank transponder key can be purchased and easily programmed, same with a remote. After a quick internet search for the directions I turned to Amazon and found blank transponder keys for around $6.50 —a price I thought would be worth the gamble to see if I could do it myself. Unprogrammed remotes can also be found on Amazon at about $25 for two.
A quick google search for “Programming a transponder key for Toyota Sienna 2006” led me to both forums and Youtube videos with the instructions. The instructions involved a series of opening doors, inserting in keys, and then waiting, but after the first try the new key was programmed and it only cost $6.50. The backup key is still not cut, but you can take it to a locksmith to cut it or use it in combination with the other cut key to start the car. Please note that a car has to have at least one working transponder key to be programmed this way.
As for the remotes, they worked the same way. A series of door openings, key turnings, and button holdings entered the car into the programming mode where we were able to program both remotes at the same time. While this isn’t an option for all vehicle models, it does open up a cheaper alternative than going to the dealership to get backups made.