E-Diff repair on a 430

My 2005 430 popped up with an E-Diff failure light and the traction control goes into rain mode by default. The local Ferrari dealer determined that the control value needed to be replaced. After driving for above 20 miles after getting the car back the same warning light came on again. Took it back to the dealer and 2 weeks later they determined that the replacement part was faulty as well and they replaced that. Drove another 20 miles and the light came on yet again. Anyone else have a problem like this? Any solutions?