Well i'm having transmission problems. So here we go. After driving through the gears and the truck being cold or warmed up, dose'nt matter and comming to a complete stop you could feel the transmission shifting into low.( feels like someone is bumping into you from the rear). This is how it started. Now i'm having to shift to neutral and then back to drive to get the transmission to shift back to first. If i don't do this it feels like the transmission is slipping. this is because the transmission is still in od. Adjusted the bands(both of them) and no change. Changed the fluid, filter,and pulled the valve body and checked for junk. Still no change. Thinking of the pressure selenoid but i don't know what its function is or if i'm just wasting money. Could be a mechanical issue which i would bring to a shop, but tring not to. if someone could explain to me what the pressure selenoid does this would be helpfull. thanks for your help.

 

I think it is for electronic control of throttle psi to make you up shifts happen. should get its signal from computer and tps sensor. i think low voltage from the computer will
make upshifts delay and aplly more psi to the bands and clutches for harder shifts. i dont know if it would cause a problem like you have, soun more like a stciking valve
in the vavle body. I have some tranny books that may help, i'll check it out.