DAMOS files and A2L, explained
A DAMOS file is the map of the map: a description, written by the people who developed the ECU software, of where every calibration table sits and what each one means. Load a matching one into WinOLS and an unlabelled binary turns into named, documented maps. The hard part is the word matching — and that is mostly what this page is about.
- What DAMOS and A2L files contain, and what they do not
- Why a near match is worse than no match
- How a mapped WinOLS project does the same job
- Ready-made projects from €69.95
What a DAMOS or A2L file contains
Not a tune. A description file carries no calibration values of its own — those live in the binary read from the control unit. What it carries is the knowledge needed to understand that binary: the memory address of every map, curve and single value; the axes each map is indexed by; the conversion formula that turns a stored raw number into a physical unit such as millibar, degrees or milligrams per stroke; and the name and function each table belongs to.
DAMOS is the older name and format, still used loosely for any file of this kind. A2L is the standardised form, defined by ASAM as MCD-2 MC and widely known as ASAP2, and it is what most current ECU software is described in. To a tuner the two do the same job: they replace guesswork with labels.
WinOLS reads both through EVC's DAMOS/A2L import plugin, which handles the .a2l, .asap2, .dam and .damos extensions and applies the definitions to the file you have open.
Why the match has to be exact
A description file belongs to one software version. When the manufacturer releases an update, tables move, change size or gain new axes, and the addresses in the old file stop pointing at the right data. A DAMOS for a neighbouring version can therefore look perfectly plausible in the editor while labelling the wrong bytes — and a change made to the wrong bytes is worse than no change, because nothing warns you.
So the first thing to check is not the file name but the software identification in the read itself, against the version the description was written for. If they do not agree, the description is not for your file, however close the numbers look.
Where DAMOS files come from
They are development documents. ECU suppliers and vehicle manufacturers produce them for their own engineers and partners, and they exist for some software versions and not for others. A matching description for your exact file may simply not be obtainable.
Copies that circulate outside those channels are of unknown origin and often unknown version, which brings the matching problem straight back: a description you cannot verify is one you cannot rely on.
Working without one
Most file tuning is done without a DAMOS at all. WinOLS's map search finds candidate tables in an unlabelled binary, and experience with a given ECU family is what turns candidates into named maps. It is slower, and it is the work a description file would have saved.
Once that work has been done for a control unit, it can be kept. A WinOLS project stores the located and named maps alongside the original read and every version made from it, so the identification never has to be repeated — which is the same benefit a DAMOS gives you, arrived at from the other direction.
A mapped project instead
Upload the read from your control unit and it is matched against the WinOLS projects we hold. When a project matches, take all of it or only the versions you need; it arrives as a WinOLS .ols file with the maps already located and named and the checksums corrected.
Projects are €69.95. If what you actually want is a finished file for one car rather than the working project behind it, a tuning file is €49.95 and needs no WinOLS licence at all.
- Full project — everything held for that control unit
- Parted project — only the versions you select
- Delivered as .ols, checksum-corrected
Frequently asked questions
Related
- WinOLS files and project database What a project file holds, how checksum correction works, and when you need a licence.
- File services Finished files rather than projects — Stage maps, deletes and drivability options.
- Tuning files Upload a read and download a checksum-corrected result in about a minute, from €49.95.