Sputtering

[Red Chevy]

It doesn’t require PICO, just GDS2, or any of the run of the mill tuning softwares of OP has a buddy with HPTuners or EFILive. You’re right about the flush being the recommended solution though. That bulletin does pretty thoroughly describe what the TCC slip would look like in GDS2 though and that would tell you if the converter is still intact. I doubt OP is to the shaved metal stage yet since he doesn’t have the CEL for no TCC lockup (which has its own TSB).

Fluid flush is probably in OP’s future. Be curious if changing out the DVI for fresh cures it.

 

[Jtink]

Transmission shop called and suggested replacement.
Said they have seen issues the the Transmission ending in 80 instead of 90 (model #) has known issue with the pump and causing the t/c failure.

Technical can be fixed, but suggested replacement with new, upgraded pump, housing, t/c
Also suggested good aftermarket trans cooler.
So new Transmission getting installed this week

 

[Red Chevy]

The 6 speeds come in a series, all of similar architecture with varied sizing of critical components to support different torque ratings. There are 6L45, 50, 80 & 90s. They all use the same converter material and dexron vi and they all appear to be susceptible to converter failure. The pump wearing out is often caused by the debris from the converter but there was also an issue where the pumps appeared to have some improperly torqued bolts resulting in leakage.

I'm not sure what pulling the transmission and having those components replaced is going to cost but I would recommend just doing a fluid flush first. If your converter was totally toast you'd have the CEL -- DTC P0741 (Torque Converter Clutch (TCC) System Stuck Off).

 

[Tiredmechanic23]

Mine failed at 94k miles. It sucks. Get it rebuilt well or go aftermarket. Since rebuild im 25k into it and its is doing great.

 

[Jtink]

I didn't realize it didn't have a trans cooler. I thought all boubs and yukons did.
That added a trans cooler for me with new transmission.