4L80 swapped, irrattic VSS & wont shift
03-27-2014, 09:24 AM
#23
Ok a little update. Since I'm going behind another tuner I decided to double check the tune to see if it has been segmented by the guy before me, I pulled a 4L80 tune up with the same OS ID and it looked the same, so then I got curious and pulled a stock 4L60 tune with that same OS and it looked the same as well. I contacted HPT and asked them if they could look at the tune that I read off this truck and see if it had been segmented by the previous tuner and they said that even they have no way of telling. So at that point I had them segment it with the matching OS 4L80 stock tune that I had and now I plan on giving that a try, I'll post up how it goes. Oh and btw, after they segmented the tune segment ID#'s for segment# 4&5 did change.
03-28-2014, 10:08 AM
#24
OK, reflashed with a tune that I know was segmented properly & now the VSS signal is clean, nothing erratic about it but the trans still wont shift. I still have codes P0748 P0758 P0753, & P1810. With the shifter in drive the trans seems to stay in second gear, when I shift it with HPT it shows that the current gear is the one Ive chosen but never actually shifts. It also shows the trans temp to be -32*
Anyone ever experienced this?
Anyone ever experienced this?
03-28-2014, 12:26 PM
#25
I figured it out & it's shifting now. I don't know if it had 2 issues or just one, they VSS smoothed out and stopped being erratic when I flashed my own tune that I know was segmented properly but it still didn't shift by itself and through 4 dtc's. I did a little more research on here and found that some people were plugging the valve body plug in backwards so I called the shop owner where the truck is and told him to flip the valve body plug around and try it. He did and now it shifts like it's supposed to.
