KTAG Firmware 7.020 can read Opel Insignia EGC17C59 successfully
Before reading EGC17C59.
All you need:
KTAG Cable 14P600KT02
16-way rainbow ribbon cable 144300T105
Two 470 Ohm resistors
Solder wire
KTAG Firmware 7.020 read Opel EDC17C59 pinout & wiring diagram
Solder the two 470 Ohm resistors on the pads as picture:

Solder a wire joining the two pins BOOT and solder a wire to pin CNF1 as picture:

Use the Cable 14P600KT02 to connect KTAG with ECU EDC17C59 as picture:
Solder the rainbow ribbon cable 144300T105 to the pads as picture: (Make sure not to make short circuit between the pads)
So connect KTAG 7.020 with Opel EDC17C59 ECU like this:
After that, open K-Suite V2.23 software.
Choose "OPEL"→ "Insignia"→ the right "BOSCH EDC17C59" and click "OK".
Choose "BOSCH EDC17C59 IROM TC1767 OPEL GPT (P688)".
Click "Read" to read ECU data and wait it complete 100%!
Tips: KTAG FW7.020 PCB Board for checking