File to change mass air flow sensor bmw 320d 136cv

[dvdtuning]

Hi to all,
I ? happened to replace the air mass meter on this bmw 320d 136cv and my co-worker told me that it was necessary to insert a file into the ecu otherwise not recognized by the meter.
We have written this gi file? ready in the database and the car ? all went well, otherwise would not do.
Can you explain the mod why? honestly I don't get it
I enclose ori and mod