Loose Connection under the seat only applies if you have Airbags in your seat
Most Punto's dont really (actives / Mia / Punto's etc)
The best way to find out is to get a Neat tool that every Fiat Driver should have
And that is Fiat Ecu Scan
Get a £10 to £15 Lead
Stick Fiat Ecu Scan on the laptop and away you go
A Decent free Auto Diagnostic that Diagnose Most faults
The Paid Version is much better tho