Asus m4a89td cpu fan error

[Dallascisco]

I'm building a new system and everything si going well so far except for a "cpu fan" error that comes up every time I boot. I have to press f1 to proceed after every restart. The system runs just fine and the temps are well within tolerance. I'm sure this is just a bios tweak but haven't found the right option yet. Anyone know which one it is?