Speedo and Gear indicator not working after 4l80e Swap
 

Just completed a 4l80e swap in and 08 Silverado got the TCM reflashed. The issue is the speedometer is not making and every other gear indicator shows the line under it...I only get the line under R,D,2 the others dont show the line.

Update..I got the gear indicator to work. When I depinned the TCM connector I had a wire not seated all the way in and another misaligned into another pin position. But i am still having issues with the speedo. The speedo doesnt move I pluged in the PLX OBD scanner and it is showing 158mph when in any gear, moving or not. Do you all think i have a bad speed sensor I am not getting any codes.

You could swap it out with the other speed sensor thats in the 80. Are you sure you pinned the pcm in the write pins, and stuck them in all the way? 158 is just defaulted cause its not working, the IAT sensor does that if not plugged in as well, IIRC it goes to 212 *

Well I ordered 2 new sensors and I am going to recheck the wiring later today.

I replaced both speed sensors...rechecked the wiring the pin outs all seem to be good and in the right place and I still have no speedo. It has to be something small but I am not seeing it....

Well i found the problem its with the tune..I plugged in my 4l60e tcm and the speedo works I plug in the reflashed TCM with a 4l80e tune and the speedo goes out...

what was the verdict with this? ive got the same problem with my truck. my converter is locking up on the highway. didnt think it would if it didnt know how fast it was going

4l80
 

Hello friend. I just swapped the 4l60 to the 80. Sent the computer out for segment swap. Repinned accordingly. No speedo and vss code. Can u help?