What revision BH is it mate?
This may help
V5/6 WRX/STI ECU Plugs/Pinouts:
https://onedrive.live.com/view.aspx?cid=CFA30F34A9604D4A&resid=CFA30F34A9604D4A%21162&app=WordPdf&wdo=1
V5/6 WRX/STI Engine wiring Diagrams:
https://onedrive.live.com/?cid=cfa30f34a9604d4a&id=CFA30F34A9604D4A%21161#cid=CFA30F34A9604D4A&id=CFA30F34A9604D4A%21164
V5/6 WRX/STI (bottom section of PDF, covers V5/6 WRX in detail)
http://reuben.xpjets.com/random/BH-Conversion/Possumlink-MY99Manual.pdf
BH5:
http://reuben.xpjets.com/random/BH-Conversion/BH-WiringDiagram-JDM.pdf
Other ECU\'s covered here:
http://www.brdevelopments.com/archive.html