Autotuner slave files: decrypt and encrypt

What Autotuner is

Autotuner is a hardware tool for reading and reprogramming control units — the device that talks to the vehicle, extracts the software and writes a modified version back. It covers engine and transmission units across a wide range of platforms, over OBD and on the bench.

It does not edit calibrations. That happens afterwards, in WinOLS or another editor, on the file the tool produced. Which is where the licence configuration starts to matter more than the hardware does.

Master and slave: what actually differs

With a master tool the files come out unencrypted. You can modify them yourself, or send them to any tuning file provider you like. The tool imposes nothing on what happens next.

With a slave tool you read and write crypted files, and those files can only be modified by one specific master — the file provider designated when the tool was bought. Your slave is linked to that master. Everything else about the tool works normally; the restriction is on the file, not on the device.

It is worth being clear that this is a commercial arrangement rather than a defect. A slave tool costs less because it comes with a provider attached. The friction appears the day you want to edit a file yourself, or work with someone else.

Why your editor will not open the file

An Autotuner slave read is a container, not a binary. It holds the same information the backup does plus the calibration data itself, encrypted and intended to be opened by a master. Load it into an editor and there is nothing recognisable inside — no maps to search for, because the map data is not in the clear.

Decryption unwraps that container into an ordinary binary: the bytes the control unit actually executes, which open and map like any master read. Encryption is the return trip, sealing your edited binary back into the shape the tool expects to flash.

What StageGen returns

A decrypt returns a plain binary with its checksum layout intact, ready to open in an editor. An encrypt returns the file re-sealed in the Autotuner slave container, so the tool writes it back without objecting.

Neither direction changes the calibration. This service converts a file between two representations of the same data — it does not tune anything, and it does not recalculate checksums. If you want checksums corrected after your edits, that is what the tuning service does.

• Decrypt → editable binary (.bin)
• Encrypt → re-sealed Autotuner slave container
• Both directions self-serve, no ticket queue

How it works

Three steps, identical to every other job on the service. The container format follows from the tool you name, so there is nothing else to configure.

• Upload the file — the slave read for a decrypt; the original read plus your modified binary for an encrypt
• Pick Autotuner as the tool
• Download the result — typically about a minute later

Paying per file, or linking your device

A job is €9.95 and covers a single file, with nothing to set up beforehand. For occasional work that is usually the whole answer.

At volume, linking your device to our master is the alternative: once linked we work directly in the native container and the decrypt step stops existing rather than being paid for repeatedly. It is also the route when a job needs more than the file on its own. The form is below.

Frequently asked questions

Related

• KESS3 files The same master/slave split on Alientech's tool, and what a decode returns.
• Crypt / Decrypt The service itself, covering Autotuner, KESS3 and MMS Flex in both directions.
• WinOLS projects Where the decrypted file goes next — with the mapping work already done.
• Tuning files Skip the editing entirely: upload your read, pick the options, download the result.