2002 LM7/4L65E Swap limp mode

[Ole Greenie]

Hi everyone,

I've been deployed so it has been a while. I am in need of some assistance concerning a recent 4l65E install that replaced my BTO 700R4...particularly concerning a limp mode condition.

So I have looked up a few previous threads but it is still a bit unclear as to what a solution might be.

Conditions:
1) Motor runs perfectly. 2002 LM7 with 4l60E (not in truck). Cable throttle.
2) Place selector into R and it wants to die. After engine warms up, all is well.
3) Place in D, it starts in 3rd gear...limp mode.
4) I can manually shift into lower gear and all is fine but it does not go into 1st gear. It starts in 2nd gear. Is this normal?
5) No engine codes. Bosch scanner does not read trans codes (maybe I should get one!)
6) Transmission (4l65E) is not "married" to the PCM. Meaning that the trans is foreign to the PCM. PCM and engine came together.
7) Painless harness 60217.
8) Everything is connected perfectly.
9) On hold with Painless for 45 minutes...hung up. What a pain!

I'm inclined to think that I need another PCM reflash. I have no idea what was programmed before...but it ran fine with the 700R4. Thoughts?

Much appreciation in advance!
John