4l80e lockup issue
 

So I've had my truck 80e swapped for 3 years now and the converter has never locked up. First we believed it was the converter so I bought another one, still didn't lock up. Then my trans builder said it was my wiring so we manually grounded whatever pin the brown wire is to the frame. Still no lock up. My tuner has commanded for it and still no lockup. Snap on scanner shows the pcm is calling for lock up and the brake signal switch is working properly so finally my trans builder tears it down to the bare case spends an entire day trouble shooting it and says there's nothing wrong with it that my wiring is to blame. I may be mistaken but if all other solenoids are working it obviously has power and all the lockup solenoid needs is a ground to come online and by manually grounding it, you eliminate the pcm and wiring as a cause for it not locking up. Is it possible the segment swap could be bad in that aspect and is causing the issue? (Even with manually grounding it). Also it's developed a brutal 1-2 and 3-4 shift lately. I've ohmed all the solenoids and they're all in spec and there's no loose grounds anywhere on the truck. Fluid level is spot on. I'm just getting real tired of it not locking up and snapping my neck when it shifts as much driving as I do. Any input at this point would be appreciated. Thanks guys.

O-ring on end of input shaft where it goes into converter there?

Anything is possible.

Was it a complete trans when you got it?

Where any hard parts replaced?

How was the PCM segment swapped?

Are you sure the lock up solenoid has the correct power to it?

I didn't tear it down so personally I didn't see the o ring, but he said it was there. Yes the solenoid is getting the correct voltage when it's calling for lockup. It was a complete trans when I got it built to hold until the stock shafts break. Dual feed mod, good clutches, billet converter. Everything you can do to one minus the hardened shafts. PCM is segment swapped but I'm not sure how they did it since I'm not the tuner. It's a weird problem. My buddy has an 80e swapped truck built by him and his works flawlessly which is another thing that makes me think it's not the trans but all the other bases of it seem to be covered besides the actual transmission.

Have your tuner check the 80e Trans diagnostic segment portion of the segment swap. May need to flash it again in the tune. I had this problem after a recent swap and had no TCC lockup. Are throwing any code?.