As I've been dialing in this transmission (4L70E in a 08 Suburban with a 6.0L), i've come across something I simply can't stop or figure out.

Take a look at the attached log file. The long story short is that when the truck is at the cusp of apply, like about 40 mph in fourth gear at partial throttle, the TCC PWM varies up and down considerably. The net effect is that TPS and VSS are constanct, but TCC PWM is up/down/up/down and the RPMs follow it.

My gut tells me there is more going on here that is being missed. I guess the root question is, what dictates the TCC PWM? I am almost betting there is another table somewhere that defines TCC PWM vs. TPS or VSS or RPM or something.

I know I can set min PWM to 80 or 90, and max to 100; but the application of the TCC is so abrupt that it feels like the driveshaft will fall out (yes, I have a high stall converter).

If my above assumption is true, it's be better if you could define the PWM based upon TPS or something, and still keep your min PWM low. You could then lower TCC apply rate, and have a nice reasonable lockup with minimal abruptness. I don't know about you all, but I'd like to see a lockup that starts at 0% PWM and goes to 100% PWM in one second or less. But, not 0 seconds.