Switch Ign on (do not start engine)
Set Odometer to read total miles.
Press Odometer Button (OB) until CFG1 appears in display
Release the OB.
Pressing the OB briefly will change between CFG1, CFG2, CFG3, CFG1
Once you have selected the CFG (see below).
Press the OB again for 5secs to store the new service frequency.
Turn off the ignition.
I selected CFG1 for my vehicle (05 Reg 2.8JTD), but you must decide yourself for your vehicle, should take 5mins to read this and carry out the resetting procedure
Note: If your vehicle is under warranty and you take it to be serviced by a Fiat dealer they will do this as part of the service.
CFG1 = 30000km (18,600mi) and 365 days in cases of Standard Use for 2.0 petrol and 2.8JTD versions, or in the case of Severe Use for the 2.3JTD versions.
CFG2 = 20000km (12,500mi) and 365 days in case of Standard Use for 2.0JTD versions, or in case of severe use for 2.0 petrol and 2.8JTD versions
CFG3 = 15000km (9,300mi) and 365 days in case of Severe Use for 2.0JTD versions