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ECU Tuning Tools Explained

Slave Tools | Master Tools | Protocols | Subscriptions

Entering the world of electronic chip tuning can be a little bewildering at first, with a wide variety of products to choose from. Here are some explanations of the basics to get you started.

  •  What is the difference between a Slave and a Master tool?
  •  What is an ECU protocol?
  •  Why do I need to have a subscription when I’ve already bought the tool?


A slave tool can read a vehicle ECU and write files back into it – but the data it reads will be encrypted and will need “unwrapping” before any modifications can be made. The decryption is carried out by a master tool – to which the slave will be electronically tied. Once the file has been modified, it will be “rewrapped” by the master tool before being written back into the ECU.

A slave tool can only use files that have been unwrapped and rewrapped by the master tool to which it is assigned – when you purchase a slave tool from us it will be tied to our master, which will carry out the decryption necessary when you send in an original file.


A master tool takes an ECU reading without encrypting the data – so there is no decoding and encoding process needed. The file can be directly edited, assuming the user has the required knowledge and training.


Protocols are programmed into a tuning tool to allow communication with a vehicle ECU. Without the protocols, the tool cannot function.

When you purchase a tuning tool, you will need to ensure that you also have the protocols that will enable you to tune the ECUs in your specialist field. For most new dealers the car/van/motorcycle protocols are sufficient; but others exist for commercial, agricultural, and marine vehicles.

When choosing tools, bear in mind in the cost of your desired protocols, some of which are included in the tool price (CMD, for example) whilst some are sold separately (Alientech). We have various tool and protocol packages available.


A yearly subscription is required for most tools to continue using them with up to date ECU protocols, so it is necessary to factor subscription costs into your overall business expenses. Attempting to run a chip tuning business without up to date subscriptions is a recipe for disaster – protocols are constantly updated and using a tool with an expired subscription can cause irrevocable damage to an ECU.

Some tools without a current subscription will also not be able to retrieve the necessary checksums when programming the ECU, leading to the car not starting and potentially having to send the ECU to us to be fixed. Failure to keep subscriptions up to date is almost certainly a false economy.