G27 keeps calibrating and shuts off

[TImothy Magee]

Just what the title says.... My G27 wheel keeps spinning to calibrate. So it will spin to the right, hit the end, then spin back to the left, hit the end, then center itself....then it shuts off. Then about 10 seconds later it will spin left and stop. Then it will spin right and stop..... and this goes on for about a minute before it finally gives up and the green LED goes out. Any ideas? Any help is appreciated!!!