After investigating a lot I found that there is only one software able to communicate with this ECU.
It is the ancient PCHUD from Delco which is mentioned in the manual of the Delphi MT05.
But this program has been written in 1993 for Windows 3.
It does not run on a 64 bit Windows which is the standard nowadays.
It is quite primitive and does not support ELM 327 adapters (which did not exist in 1993)
So I began to reverse engineer this old software (which was difficult to find) and wrote my own program which now replaces it: HUD ECU Hacker
I designed HUD ECU Hacker as "community software".
This means that the program is 100% configurable by the user in an XML file.
This "parameter file" contains the commands sent to the ECU and how to interpret the responses.
This allows to adapt HUD ECU Hacker also to other ECU's.
The program is still growing. I added lots of new features in the last months.
Now it can also download the flash memory from the ECU with the calibration tables, correct the checksum and program the flash memory (tuning).
HUD ECU Hacker finds calibration tables automatically in a flash memory file. It finds approx 170 tables and 500 scalar values.
Calibration tables can also be displayed as 3D model.
Download and detailed description here: