Ok so I have a built 4l80e with jakes performance d3 trans brake and a jakes stall. When I first installed the trans it shifted in auto perfectly as well as in manual. Now if I drop it into d1 it goes in and drives. As soon as I shift it into 2nd it will either hit 2nd and jump right out like its in neutral or itll just act like its in neutral without goin into 2nd. Heres the funny thing though. While its in this neutral state if I hit the gas it acts like there is a huge stall in it. Itll go up to 4500 and feel like its grabbing.

If im in od or d and pull it down into 2nd while driving it will not go in 2nd....neutral state again.....but it shifts perfectly in d or od by itself. I have looked over the tune but dont see anything that would cause this. All of my normal, cruise, and performance shift tables are all the same. Not sure if this could be an internal issue or what could cause this. Please give your input.

 

It's fine in auto 2nd gear at all times though?

 

Yes if I just put it in drive or overdrive it shifts perfect into second no prob. But if I put in d2 and try to let it shift 1-2 by itself it wont.

 

Likely a tune issue. It may not like the data from the pressure switch or the PRNDL switch if applicable.

 

How can I check/fix that. Wish I would have went full manual vb now....ugh lol

 

PRNDL switch is not hooked up. Also not showing any codes

 

Does it not have a PRNDL switch or it's not hooked up?

 

Not hooked up. Its not on the trans any more. It was shifting manually. Then it just quit.

 

Bump ttt.