AV inputs questions

[br21]

I have a question regarding AV inputs in Subaru plug N play ECU.
I've got Motec documentation to this ECU, but some things I can't find there:
M800 OEM WRX78 Installation Document
AV4 (internal barometer connected to that pin???) and AV6


In Lancer evo9, AV2 which is Alternator input, gives voltage proportional to load which makes using this AV input for some other sensors impossible. Maybe somebody knows if there is any way of turning that voltage output off thus making that AV available for other use.