I have an 03 with an auto transmission. The problem is it starts out in second gear when in drive. The only way i can get it to start out in first is to shift it into first, then shift to second manually, but then it won't shift back to first if i shift it back. I have to come to a dead stop put the truck in first then it will start in first again. When idling at a stop light in drive you can feel the truck give a slight quick jerk once in awhile as it shifts in to first but then shifts back into second. Another thing it does is when shifting from 3 to o/d under light throttle the trans gets confused, the rpm's jump up and down, it's like it doesn't know if it should shift or not. It only does the under light throttle, under harder acceleration it shifts fine from 3rd to o/d. trans fluid looks good, doesn't smell burnt and is at proper level.

 

I have the exact same problem with my 01, I was really hoping somebody had some answers. the guys here are pretty good at pinpointing a fix.