Electrical problem
2002 Fiat Stilo Two Wheel Drive Manual 30000 miles

hi there, i bought a fiat stilo a couple of weeks ago. the car has been fine. i tried to start my car, and the and i wouldn't start. the battery is fine. my car has an anti slip regulator (ASR) system and the car will not start without it. when i turn the key so the car is on electric the dasboard says. security/////ASR failure//// loose connection. and the immobiliser symbol is lit. none of these signs were preasnt before. i took it to my fiat garage because i assumed they know most about fiat. they charged me  £60 for a diagnosis and then found out that the car as an electrical problem. they want another  £240 to find out whats wrong with it. i'm guessing theirs a loose connection in the ASR system but i dont know where to start. i could find any documents on the net about fiat stilos so i can have a bach my self. can you give some advice