Green Key Light Flashing
2000 Accord, Car Ran Fine,Parked For 2
Weeks,Now When You Insert Either Key,It Will Turn
Over But Not Start.Green Key Light Flashing On
Dash.Checked Fuses Inside Car And Under
Hood,Battery Voltage.Has The Car Lost Memory Of
Could be or the keys have stopped transmitting. Try a lock smith first, he may have the ability to do a reset on the system or make new keys and reprogram the system for new keys. Other wise your stuck with the dealership and that will get expensive.
There's a method you can use to resync the key to the car manually. If it turns the cylinder but flashes that light I'd start there. There are some good youtube videos on how to do it. I believe it is called immobilizer control.