I just have noticed that a previous owner of my car had modified something in my P2T ECU, put a small green board connected to the VBU pinout (in 25pins connector). What a VBU (Backup Power) does exactly? What sign can this board modify? Do you think i can remove this board from the VBU line? I think this boards changes the sign of VBU line (as it is put in the line exactly) for some reason...

I'll take a photo about this stupid hack in the evening.

 

Here are the photos:





So what the VBU is good for? Anyone?