As best I can tell, my S60 is simply giving the briefest of stabs to the brakes on the slipping side so more power is transferred to the non-slipping side. It certainly doesn't cut power, at least not noticeably. I've got enough power to break it loose in 3rd gear on dry pavement, but this time of year even the "dry" pavement is slippery due to salt and sand buildup. It still accelerates like crazy even with the traction warning in the dash flashing. I'll have to take it on ice sometime and just pour on the coals to see if it'll limit power or not.