2004 Avalon security system reset

My Dad's car has been sitting for 2-3yrs. I had to replace the battery, but now I
can't get the security light to stop flashing. I have tried the following:
- using key to lock and unlock doors
- using key fob to lock and unlock doors
- putting key in "on" position for 10minutes, then "off" for 5 seconds. repeat 3x
- putting key in "on" position for 30mins, then off
- Jumped pins 4 and 13 on the OBD plug and put key in "on" position for
30mins.
- Disconnected battery for 15mins
However, Nothing has worked.

Any other ideas? Kind of at my wits end....thank in advance.