I was informed the other day that the 3.0ltr 180 multijet is actually an Iveco engine, not sure how true this is, so is the mechanical lump Iveco and all the ancillaries fiat, or is this complete nonsense?
Iveco engines are part of Fiat Group Automobiles, and previously Fiat Powertrain Technologies (FPT Industrial). The 2.3 multijet is also an Iveco branded engine. Many parts are shared between Fiat and Iveco vehicles, particularly on the Ducato and Iveco Daily, some of which use the same engines and other assemblies.
However, the diagnostic systems are different. Except for the internationally agreed emission codes, fault codes on Iveco vehicles are incompatible with Fiat and vice versa. A basic generic fault code reader should be able to read emission fault codes on both vehicles and some of the more fancy ones may read a handful of other units, but to read, test and carry out the full fault tracing and diagnostic function designed by the manufacturer, their own diagnostic system needs to be used. There are various aftermarket systems that can also carry out many of the functions on a wide range of vehicles, as used by independent garages, but an Iveco or Fiat dealer is not going to invest in one of those when they have to pay a substantial ongoing cost to install and use the manufacturer's own system.