first don't worry about 'combinations of adx or xdf'. it will communicate exactly the same regardless of the XDF loaded - you could even have one loaded from a different vehicle

to start communicating with a gm ecm of this generation you need to become master of the aldl bus by telling the current bus master to be quiet. that's the difficult part and tunerpro in combination with a higher latency serial interface can be less than ideal.

one thing people try is connect over and over again until it works. you will eventually fluke out.

you might want to use the data list to start with instead of the dashboard just in case there is an issue with your dashboard