Correct. If input speed vs. turbine speed 'delta' (I feel so scientific now ) is over 600rpm or so, the TCM will not lock the converter. This "magic table" bypasses/overrides all of the other TCC lockup tables.
Also, another thing is the earlier 5-speed OS's unlock the converter during a WOT downshift. IE, if you are on the highway locked in 5th gear at 65mph, and floor it to pass someone, the converter unlocks and then the trans does a 5-4 kickdown...of course the converter is supposed to relock immediately after the shift completes, but due to looser converters, with that immediate inrush of power from the RPM increase and turbo spool, the engine "blows through" the converter, crosses that "tc slip lockup inhibit" threshold and then you sit there screaming in 4th gear unlocked, not even accellerating...then after 3 seconds or so the converter will finally lockup, and only THEN will it shift back into 5th. Because WOT in 4th gear unlocked, the truck wont actually accellerate (to the WOT 4-5 shift mph) because of the power required to make a 7,000lb brick accellerate at 65mph gets lost when the converter isnt locked. Sometimes its bad enough that Ill sit in 4th gear rpms screaming, trying to pass someone, ill have to let off the throttle a bit to lower the slip rpm's, converter locks, then I mat it again and accellerate back up to the WOT 4-5 shift point at 80mph or whatever, and then I pass the car.
NOW....interestingly the LLY (or at least the 05 LLY TCM) operating systems DO NOT DO THIS. If you are on the highway in 65mph locked 5th gear, and go WOT to pass someone, the converter stays LOCKED. Which is very nice, because then you can actually pass cars effortlessly....you dont have to sit there not accellerating waiting for the converter to relock after the shift.
My thinking on this is on the early LB7 TCM OS's GM carried over thinking from the 4L60/4L80 transmissions, that the converter has to unlock during a WOT downshift to not shock the trans or damage it. The allison isnt susecptable to damage like this; even a stock allison is perfectly fine doing locked WOT upshifts and downshifts. They probably figured this out by the time the LLY came out (and maybe even due to people complaining about the 5-4 WOT downshift and converter not wanting to relock??) and changed some code in the TCM to make the converter stay locked during WOT downshifts.
Also, if it helps in tracking down the code, I THINK trans fluid temperature is a factor in this calculation/inhibit table. Because to me, TC lockup seems more "deliberate" and "prompt" when the fluid is colder. As the fluid warms up above 130* or so, lockup seems to get cushioned a fair amount.
And finally, D5072 doesnt seem to do anything. Im not sure if its mislabeled or something, but Ive severely modified it various ways and it doesnt really have any effect on how "harsh" or fast lockup occurs. The PSI in that table I dont think is correct either, as the Allison TCM doesnt really have any reference to actual TC pressures.
Final question, from what I have seen, varying the torque tables does not seem to have an effect on lockup harshness/speed/delay...but that might just be me? I dont know if lockup references torque in any way or not???
Ross let me know if you need anymore info or logs, or if any of my above descriptions dont make sense.
Ben