I have an 04 Duramax LB7 w/ the Allison 5 speed automatic. It is a 2WD w/ a 76HP BullyDog tune. The other day I tried brake torquing and manually put it in 2nd. It shifted and downshifted and the tried to shift again but went into neutral and slipped. It didn't want to move at all after until I restarted it and tried. I also got Range Shift Inhibited. If you gave it any gas after that it would want to slip even in 1st. I managed to get home and it shifted through all the gears it seemed like and would hold the higher gears. It did slip between a lot of shifts, but if you let off completely and barely gave it any gas it would shift. The next day I took off the programmer and tried, but it wouldn't shift out of 1st. Then after playing with it I completely lost first. Only have reverse. I get codes P0700 P0732 P0776 P0843. The mechanic said the TCM was bad, so I got one and no luck. Any suggestions?
