I have been running 255/35-18's on the front and 275/35-18's on the rear for over four years with no problem whatsoever. This error code started appearing AFTER I got back the IPT rebuilt transmission. Jason @BIP suspects that the power now going thru the transmission is overwhelming the TCU. Since the rears were about worn out I have just replaced them with smaller 265/35-18's to see if the tire size has any effect - nope. Somehow the TCU has to be programmed to be more tolerant of the new power.