Before diving into the "how," let's discuss the "why." Many generic OBD2 scanners on Amazon claim to work with all cars. They will read basic emissions-related codes (P0300, P0420, etc.). However, Fiats are notoriously complex.
Some Fiats require the ignition to be cycled off/on between module scans. If you scan the Engine, then the ABS, disconnect the app and cycle the key. fiat ecu scan android
A setup differs from a generic scan because it accesses proprietary systems . A generic scanner cannot see: Before diving into the "how," let's discuss the "why