I just programmed my SIENNA XLE 04 with some procedere I found for a highlander ...
1. Start with the following conditions: You are in the drivers seat.
a. Key is out of the ignition
b. Driver door is open (all other doors closed)
c. Driver door is unlocked (other doors don't matter)
2. Insert and remove the key from the ignition twice within 5 seconds.
3. Close and open the drivers door twice within 40 seconds.
4. Insert the key into the ignition and remove it.
5. Close and open the drivers door twice within 40 seconds.
6. Insert the key into the ignition.
7. Close the door
8. Turn the key in the ignition on and then off.
9. Remove the key from the ignition.
10. The power locks should automatically cycle once to indicate that you have successfully entered program mode.
11. Within 40 seconds of the entering program mode.
a. press both transmitter lock and unlock buttons SIMULTANEOUSLY for a duration of from 1 to 1.5 seconds.
b. within 3 seconds, press the transmitter lock button for more than 1 second and release.
c. If the transmitter has been sucessfully programmed, the power locks will automatically cycle once. If they cycle twice, the remote has not been accepted.
d. If multiple remotes are to be programmed, repeat steps A-C.
12. Open the driver's door to leave programming mode
You should be done, check the remotes!
Hope this is of help for someone else as well to save some bucks ...
Drive save!