just got a question regarding the front loom on a gc8/gf8 audm wrx...

where the front loom enters the cabin in the drivers footwell there are 5 plugs, one goes to the interior fusebox, 3 go to the main dash loom, the remaining plug goes to?????

i'm guessing there is some black box of sorts that it plugs into that i'm missing resulting in my abs light remaining on?

if anyone knows it would be greatly appreciated, cheers