Well completed the swap and dropped out to tuner. Tuner says all is great but 3rd does not seem to engage and goes into 4th. Command is sent to go into third but he does not believe it is hitting 3rd.

1999 GMC with 5.3( was a 4.8 truck)
Fresh built 4l80e
We repined the harness.
Found a OS with 4l80e for tune.
3200 stall that is locking up properly
All gears work perfect and shift great but 3rd.

Any ideas.

 

This is the wire guid we followed 4L60E to 4L80E Conversion

 

Using hptuners can you hear the 2-3 solenoid clicking when energized?

 

Also, make sure all trans dtcs are set to throw error on first error. I enabled and did this for a ton while error testing my 80e swap.

 

OK... Thanks all. But weird thing .. I made this post while sitting in parking lot waiting on tuner to return.
1rst run with me it did it.. Skipped third and would surge rpm.
2end run after returning to shop it did just like it was supposed to .
3rd run after getting back checking level of fluid same thing as 1.
4 and 5th run it was fine. So i left it there till tonight when i can go get it. Hopefully it wont do it.
We may be thinking assembly lube was blocking valve body and took a good running to help flush it out.

Any weird thing is that now my abs a brake light are on. Maybe coincidence..i duno.. will report back.