1995 chevy s10 transmission problems HELP

alright guys i have a 1995 chevy s10 4wd zr2 pickup truck the engine is a cpi with the engine code w, Now my transmission is messing up , Its wierd I had both shift siloniods replaced and it still wont leave 3rd gear , i can put it in 2nd gear and it will go into 2nd but not first or overdrive , Its wired i had a scanner hooked up to it and it reads when u turn the key that the 1st silniod is working then all the sudden when u put it in drive it goes off Wierd, But anyways Can it be my pcm And or What eles could it be It confusing the hell out of me , Any info would be awsome , Ohh yeh the pcm code is 16193495
and i was reading that i have to get the ecu reprogramed and flashed Why is there any way around this
Thank you Dewayne