4L60E shifting problem

[4 cruzin]

I have a 1970 El Camino with a LS1 and a4L60E transmission and a 2002 Escalade computer .Since I am not proficient with the tuning program I have had 3 different programmers try to correct the issue. With that said the issue is when I am stopped in drive the transmission starts in first gear with no shifting problems. Once I stop and manually shift to first gear the transmission automatically starts in second gear. I have not been able to figure out the problem. I also tried a 2002 Avalanche computer but with the same program without any luck. Any help will be appreciated.

[legerwn]

Have you tried to disconnect the shifting cable and make sure its going to 1st gear by hand at the trans.

If shifted to second gear it will take off in second gear.

[JoeR]

Or just log the trans data. It will tell you commanded gear. If you're pulling it into L1 but the scanner reads L2, you just figured it out.
Joe

[4 cruzin]

Have you tried to disconnect the shifting cable and make sure its going to 1st gear by hand at the trans.

If shifted to second gear it will take off in second gear.

We verified that a couple of times
Thanks

[4 cruzin]

I didn't want to complicate the issue with more information but hear we go. If I am down shifting while slowing the car, when I am going slow enough (around 5mpg) and manually shift to first it will down shift to first gear about 50% of the time. While viewing the trans with a tech two when it does shift into first as soon as the car comes to a complete stop the ECM will shift into 2nd gear every time. I had the valve body and solenoids replaced and it still does the same thing.