This week, I have planed to disconnect each sensor one by one to see the effect.
I will start by the lambda......

Is it normal that with VAG-COM there is nothing in the mesured value block ? (I've got an red message meaning that it is unavalaible (but it works well on a A4 TDI))
I've read the Self Study Program (found on emule) about Motronic, it seems that block 04 and 08 should work !