Could be as simple as a brake switch or just calibration or speed sensor but you really need to get it conected to a diag machine to see whats what really and get any codes read that might be on the ecu..

http://www.clubfiat.net/tech/2772-se...-problems.html

I tell you what, these Selespeed gearboxes utimatly are dead simple, and robust, except for the crap sensors and electrical connections used. Unfortunatly I'm more of a Panda Selespeed expert, than a Stilo, but I'd be looking towards gearbox possition sensor (no sure the propper name, but tells the car what gear its in.). Is a 3 pin plug at the front of the box on the Stilo.

Jon.