Hi all,
I recently purchased a 2006 Sierria 1500 that already had a swapped 4L80 that was not working. The 4L80 was swapped with the Michigan Motorsport swap harness and pins installed in the ECM. With the original tune the TC would not lockup unless commanded via HP tuners.
Reading on here, I found you need to complete a segment swap with a vehicle of same year and OS. I uploaded and still not TC lockup, but still can command. I am stumped and do not know where to go from here.
Can someone look at my tune and let me know if I am missing something?
Stock 4l80 with same OS.hpt2006 gmc 4 door OG tune.hpt2006 gmc 4 door with STOCK 4L80 tune same OS.hpt