4L80E troubles

[ED MEEK]

tranny had been shifting hard and i took it to trans shop. they pulled codes, told me it was selonoids and tps that were weak and sticking.
probably shouldnt have but i drove for a week or so longer. then tranny wouldnt shift out of 1st.
so replaced selonoids and tps, to no avail, still no up shift. tried to pull codes with paper clip, but all i get is code 12

[ED MEEK]

by the way this is my '93 2500 that has trouble

[rjschoolcraft]

Check all of your grounds and make sure all connections are good. Mine has done this occasionally, but a shut down and restart cured it. Kinda "reboot the computer", if you know what I mean. Sounds like yours is different, though.

[ED MEEK]

well i went ahead and bought both speed sensors, and bingo, it started shifting up through 4th.it did not however go into lockup! cleared codes and ran truck around the block. this time still no lockup, but when i accellerated in 4th, it downshifted to 3rd, and never shifted back up. pulled codes again and it gave me a code 68. does anyone have any ideas? all shifts feel firm with no slipping.
'93 chevy 4L80E