just installed a remaned trans in a 97 12v the truck will not shift on its own. if you drop the shifter into drive it starts off in drive. if you manually shift it it shifts fine. also o/d will not engage. the same problems that killed the last trans. where to look next. all gauges work fine and the o/d light works Rob

 

I'm not really an expert but have you tested the TPS?

 

tested out fine. took it to aamco and they put a scan tool on it and a lot of codes they reset the code took for a ride and everytime the trans was to shift it threw a code they tried to reflash the pcm and it would not take so I am leaning towards a bad pcm??

 

Tell us what codes came up.

 

a lot= I remember od lockup sensor was throwing one, a shift sensor or speed sensor everytime the trans was to shift it would throw a code and not shift