Kess is mostly for working over the OBD Port in the Car. For newer cars from 2011 with EDC17/MED17… ECU they archieved the Virtual Reading, so you have to make ID of ECU and get the ORI File from Alientech (not for clones!) or from your Tuner. Then the Ori file can be modified and you can flash it over OBD Port. You only have to sit in the car and flash a file. For old Diesel and Fuel Cars till 2008 (EDC15/16) you can also read the file and modify it.
It is easy to do, but if something goes wrong on the newer cars like EDC17/MED17, checksum error or wrong calculation you have some problems to fix it. Like Car not starting or error in ECU (e.g. flash original Soft with original Tool) Not every car can be made with kess!
KTag is the safest and also the most dangerous possibility. With this Tool you work direct at the ECU Board.
The dangerous thing is to get the ECU from the Car and open it. It is glued with some black silicone, so you must make it hot, lever open the case and also cut the glue. When you harm the board inside, with the knife or with a screw driver you are in big trouble. I first got 3 cheap broken EDC17 ECU’s on eBay to learn how I can open those ecus. Now i can open them so clean, that no one can tell if it was opened. The first one was a big fail, so you better try first with some cheap broken ecu from the net.
With KTag you can read direct over tricore boot from the board and have a good backup. If something wrong happens, you can put back the backup and no one can tell directly that there was a modification or you can fix a not starting car. More cars can be done with KTag so you see, you need Kess and KTag
I attached some pictures for you to see how dangerous open the ECU for KTag can be.
1. 1 of 3 Broken ECU from eBay – First ever opened ECU in my life without patience
2.4th ECU from Friends car.
3.Now normal opening conditions – ECU already opened and closed after tuning.