Same thing happened to me, its a pretty common fault. Could be a number of things; motor, torque sensors, even a fuse or loose wire.
Getting a remanufactured Steering Rack/ecu/motor fitted. Part cost £220 expecting another £100 to fit. Fiat will sting you for about £650.
My car has failed its MOT and has been classified as dangerous to drive because the EPAS failed. I find the car ok to drive and in some respects better than with the PAS operation (road feel). Have queried the dangerous failure as I believe the EPAS failure to be fail safe (still rack and pinion steering and is only 'assisted'). Apparently a similar fault has occurred with the new Mini and VOSA have stated the vehicle is still safe to drive with PAS failure.
Jon, March 2009
