2012 Cadillac CTS-V, 6.2L A6 transmission. The customer runs a slightly taller drag radial on the rear. He has pullied the S/C so the tuning has been only slightly modified to account for the added boost. After about a week of driving, he can no longer turn traction control off.....pushing the button seems to do nothing. Could this be related to the staggered tire size? The TCS and Stabilitrak worked fine after it left the dyno and the problem seemed to crop up after about a week.