Is overdrive controlled in the pcm?

[BR3W CITY]

I remember doing the road test with Tom checking the shift point, but don't remember talking about the overdrive. On my extended trip to ky and back, I noticed that it was hesitant to go into o/d, and would pop out of o/d randomly. Are o/d parameters something that is pcm controlled, or is it possible there is a mechanical problem?

I should note that there was no slipping or other problems, just didn't want to drop into o/d sometimes, or would pick a random time to do so....It really liked popping into o/d under load up hills, wtf.

[BAD LS1]

Are we talking od or converter lockup? The tc lockup feels like a 5th gear. To answer the main question, the tcc and 4th gear commands are controlled by the PCM. However as I've delved into auto trans work, I've found that the PCM may be properly commanding certain things to happen, but the way the trans is setup internally to complete these tasks is a different story. It seems to be that most trans shops leave the PWM function of the tcc lockup function intact with an aftermarket converter with a lockup clutch that doesn't like to be "feathered" in and will cause this erratic behavior. I guess I'd have to see it happen to better i.d. What is happening to say for sure. This sounds like a 60e I delbt with recently, and it was mechanical issue, the fix was a complete transgo shift kit vs the enlarged holes and 2 diff springs the shop said was a shift kit.

Moral of the story is, the PCM will not pick rand times for things to happen, it works all off from 3 inputs: tps, mph and rpm. If the criteria is met the command will happen provided all is well mechanically.

[BR3W CITY]

hmmm ok. I had my 4l80e done at All World out in Waukesha.
Now that you say something I'll have to drive it again quick and see exactly what I'm feeling. IIRC i think lockup is actually the concern. Basically, with my 3:73 and the current tire setup, I'm at like 2850rpm at ~70, then it will drop to about 2600 or so and feel like the "next gear". After cruising for a bit, it will just "kick down" raise the rpms back up to the 28-2900 range.

[BR3W CITY]

from what it feels like i think the problem is the lockup. IIRC the 4l80e can lockup in 3rd and up, and I'm definately not getting it.

Any idea where to start (besides google, I'll do that myself)?