Three different things get sold as "a file", and shops lose afternoons to the difference.
An original file is the baseline
An original — a stock file, an ori file, a factory calibration — is the calibration exactly as the manufacturer wrote it. Maps, limits and checksum are the ones the module shipped with.
That is what makes it useful even when nobody wants it on the truck. A module that has been read, flashed and edited by three people over ten years has no baseline left. This is the baseline.
A mod file is a finished starting point
A mod file has already been changed from that original. You are buying the finished file rather than a service: it downloads immediately, checksum intact.
- It is matched by the number on the module, like everything else.
- What you do with a calibration, and whether it is permitted where you work, is your call as the shop doing the work.
An A2L is not a calibration at all
An A2L describes one. It is the list of what lives where inside the module — names, addresses, units, conversion factors. On its own it does nothing to an engine.
What it changes is the work. Without one you are reading a hex dump. With the matching one you are reading a document.
An A2L belongs to a software version, not to a truck. Use the wrong one and it will label the wrong things confidently.
Choosing in one line
Returning a module to stock, or need a reference? Original. Want the calibration already built? Mod. Want to understand what is inside before touching it? A2L.