Got a 96 Century that with a TCC that locks up 100% directly after the 1-2 shift. Won't come out untill a coast down back to 2-1. A friend at GM says there is info on this (96, 97, 98, 99 4T60/4T60E TCC ENGAGES AFTER 1-2 SHIFT) but can't give me any details. A... Login to read more.