Random TCC unlock caused by $EE LT1 PCM - any help?

I need to throw this out there and get additional ideas:

'94 LT1 / 4L60E. TCC intermittently unlocks on the highway. The PCM is telling the trans to do it.

I have swapped:

• TPS
• brake pedal switch
• transmissions (unrelated - lost reverse due to the 93-95 design flaw)
• Found ECT connector at water pump was corroded and intermittently open circuit (causing PCM to think ECT was -40C - but this only caused 1/3 of the unlock events). I cleaned this.

I did NOT tweak the tune other then unchecking "TCC release at low TPS" and "TCC release at rapid TPS decrease."

I can post a datamaster log if you like - there is nothing obvious to me in the logs that is indicating an unlock.

I never got around to swapping PCMs but can if maybe there's a possibility that there's a bad input?

What else controls TCC lock?

any knock?

Logs might help. TCC can unlock when load is high, when trans temp is high, when throttle changes position, when brakes are applied, when throttle is closed or open, during upshift / downshift conditions.

If you use TunerPro RT and the $EE files I've worked on you can change it from logging engine data to logging Transmission data!