4l80e swapped, no 4th gear

[Zacklee420]

This really sounds like a wiring or tuning issue. I know you said the wiring has been double and triple checked, but are you 100% positive that the ISS is wired to the correct two pins at the PCM and you've moved the correct pins/wires in the transmission connector? The factory service manuals have PCM pinouts for each engine type, are you sure you were looking at the right one?

It is in the right pinouts, I did try switching the pins around to see if it was backwards but that didn't fix anything

 

[Zacklee420]

Are ISS and OSS switched?

No the output is still on the tcase the input is the only thing I had to add in

 

[Thenameless]

What did you figure out after all this time? I am having same issues and having a hard time finding answers.

 

[NickTransmissions]

What did you figure out after all this time? I am having same issues and having a hard time finding answers.

Id start a thread with your specific issue along with year, make, model and transmission. If you do I'll respond in your new thread.

 

[Thenameless]

Id start a thread with your specific issue along with year, make, model and transmission. If you do I'll respond in your new thread.

Thanks! I did so.