I?ve used hptuners on my (otherwise stock) 2012 5.3L Sierra with the 6l80 for the last 8 years. I?ve noticed strange behavior when I do any trans tuning.

After I modify any trans table, and then take it on a test drive, the transmission whines. It?s a High fluid pressure / pump whine, which can easily be heard from within the cab under heavy throttle.

I know what you?re thinking. It?s a mechanical issue. But it?s not. Here?s the thing - When I put the table parameters back to stock the whine goes away.

Now you?re thinking I?m tweaking the wrong tables which is causing the pressure to be too high. Also not the case - I?ve tried modifying just the interial factor table. It whines. Put it back to stock. It?s quiet. Go to the TCC lockup table and make a modification, the whine returns. Put back to stock, noise goes away.

I?ve done the suite updates over the years hoping it would be resolved, but no such luck. Not sure if I?m reporting this in the right spot but not sure what else to do.

Thanks in advance.