FAQ
Questions about KESS3 and buying from MMT
What is the difference between a KESS3 slave and a master?
A master tool opens and saves any file it reads, so you write your own maps in tuning software. A slave tool is linked to one master: the files it reads go to that master to be tuned, and it writes back only what that master sends. Buy a slave from us and that master is MMT.
What do OBD, bench and boot mean?
OBD reads and writes through the diagnostic socket with the ECU still in the vehicle. Bench connects to the ECU out of the vehicle, through its connector. Boot opens the ECU and connects to the board, for units that cannot be read any other way. KESS3 does all three in one tool, for the protocols that are active on it.
Which vehicles does KESS3 cover?
Protocols are sold by vehicle group: cars and LCVs; bikes, ATVs and UTVs; agriculture, trucks and buses; marine and PWC. Coverage is decided ECU by ECU, so check Alientech’s official vehicle list, or send us the ECU reference on WhatsApp and we will tell you before you buy.
Is there a subscription?
Each protocol licence comes with a subscription period that brings Alientech’s updates and new vehicles; renewals are sold separately. Every kit on this site lists exactly what is in it.
How do I get my files back from MMT?
Read the vehicle with your KESS3, upload the file to your MMT portal, and MMT tunes it in house. You get a message when it is ready, download it from the portal and write it back with the same tool.
Can I upgrade from slave to master later?
Yes. Alientech sells slave-to-master upgrades for each protocol group, so the tool you start with is the tool you keep. Ask MMT when you are ready.
Are the tools genuine?
Every tool on this site is supplied by MMT Performance as an authorised Alientech dealer and registered to you. Cloned tools damage ECUs and get no updates; we do not sell or support them.
Do you deliver?
Yes, across the UK, or collect from MMT in Nottingham. When you order, MMT confirms the delivery date with you.
MMT Performance · Nottingham
Your question is not here? Ask MMT.
Opens 8am today. Send us the vehicle or the ECU reference and we will tell you what reads it and what it costs.