Master or slave tool

Updated 23 October 2026

Choosing between a Master and Slave tuning tool means choosing how your workshop will obtain its tuning files. Will you develop calibrations yourself, buy files from different suppliers, or work with one linked file provider? If you already own a tool, understanding that relationship is also the first step towards changing your file service.

What is the difference between Master and Slave?

A Master setup gives you access to files you can edit yourself or send to a compatible tuning file provider. AutoTuner confirms that its Master files are unencrypted and can be edited with software supporting the binary format. A Master tool does not require you to become a calibration developer: you can still outsource the file work. See AutoTuner's Master and Slave explanation.

A Slave setup connects your tool to a designated Master. You read the vehicle, send the file to that provider and write the returned modification using the supported procedure. AutoTuner's Slave files are encrypted for its linked Master. Alientech describes the KESS3 Slave workflow similarly: the Master supplies the modified file ready for writing. See Alientech's KESS3 configurations.

Choose the working relationship before the hardware

A Slave setup can suit a garage that wants to concentrate on vehicle preparation, programming and customer service while outsourcing calibration. Compare the provider's communication, revision process, availability and experience with the vehicles you actually see.

A Master setup can suit a workshop that wants to choose between file providers or develop calibrations in-house. Budget for the required editing software, training and validation if you intend to modify files yourself. Neither label removes the need for correct vehicle identification, supported protocols and careful programming procedures.

Browse our tuning tools and chiptuning file service together when planning your setup.

Already own a tool and want to change file provider?

First confirm whether your device is Master or Slave. With an AutoTuner Master, you can send compatible files to a provider of your choice. With a Slave, changing provider may require changing the linked Master; uploading its encrypted file to another service is not a substitute for that process.

For AutoTuner, the manufacturer requires the current Master's approval to change Master. Alientech also requires current-Master authorisation for a KESS3 Slave transfer and says to check the dealer's terms. Manufacturer procedures and your supplier agreement are separate checks: obtain both before scheduling the move. Read Alientech's transfer guidance.

Check these details before switching or upgrading

• Your tool brand, serial number, Master or Slave status and current provider.
• The ECU and TCU protocols already activated, plus any subscription requirements.
• Required release approval, transfer or upgrade charges, and how existing credits are treated.
• The new provider's supported workflow, revision process and arrangements for ongoing jobs.

Ask for written confirmation of compatibility and the total cost. Changing Master and upgrading from Slave to Master are different requests. Our KESS3 Slave to Master upgrade listing, for example, covers existing activated protocols; it does not add further protocols.

Preparing a file request? Use our ECU file handover checklist to keep the identification and source files together.

Discuss your existing setup with MyChiptuningfiles

Send us your tool details, typical vehicles and whether you want a linked Slave service or file support for a Master tool. Contact our team to check the available route before buying replacement hardware or arranging a transfer.