or it could be a fault sensor tell the ecu the wheels a lockin thus causing the abs to kick in if can get it on a vag com that should giv eu a bit more of a clue
yeha it s small pipe on the back corner of the rocker cover on to the air intake, wel u mite havea small oil; leak then mate try and have a good look around
ermm have to find out wot way round it works, ie if it gives the 12volts to the pup when hot or takes it away, try unpl;uggin it and see wot happens, do the fans runn all the time too
yeha coul dbe the breather pipe check it for splits or hangin off if not the only other thing it col dbe is the rocker cover seal mate, normal leak from the rear corners