I have successfully reading a VW Passat year 2016 Bosch EDC17C74 ECU using KTAG.
I bought Ktag 7.020 SW V2.25 with Red PCB EU because I want to read an EDC17C74 ECU but it caused many headache. I cannot afford an original ktag, so got the clone instead.
In the first step verify your cables. I have attached a drawing found on the net and you can check your GPT cable. In my case the Chinese GPT cable it is reversed the orange and the yellow. You can see in the first and second picture that the pin 21 orange cable and pin 18 is yellow. According the kess diagram original need to be yellow pin 21 and orange pin 18.
Next step use a powerful adapter. I used an 1A adapter but after changed with a 2A worked fine.
Now I can read and write without any problem a BOSCH EDC17C74 ECU with protocol P705, both flash and EEPROM.