I have a friend of mine who's car is shifting way before the disired shift points. He had it tuned by a big name tuner, but it was on a dyno so he probably never verified the trans settings. It's a rossler terminator 3 4l60e with a trans brake. It seems to launch good and shift 1st to 2nd fine, then 3rd and 4th are too early. From a roll it doesn't seem to do it as bad. Do you think this would be a tuning issue or a mechanical issue. I tried to raise his mph and rpm settings and they didn't help any. I also tried to zero out his mph and see if it would shift by RPM only but it still short shifted. Anybody had this type of problem before? I don't know much about tuning autos, but I downloaded a config I found to help
TPS faults will cause this (like if somebody went over-the-top
with the Dremel, and the TPS voltage goes too high at WOT).
It needs 10 seconds there to set a code but none at all to
fall into short-shifting fault response.
Yeah, I came across one of your old posts and gave it a try yesterday. 4.75 volts at wot so we backed it down a little and now it's shifting like it's suppose to. Thanks for your help again