2015 6L80 GMC
140-ish K
Last week, driving home noticed my RPM's were higher than they should be at 45 mph. Dropped back a couple of gears, and they didn't go up until I got it back to 3rd.
So I assume it was stuck in 4th.
Then noticed it would rev way up before shifting, like 4500 RPM, even just barely accelerating. And didn't seem to shift past 4th.
Got home, checked fluid, didn't look/smell burnt, wasn't too dirty. Checked the code, P0741. Did the usually "check the internet" and found it could be anywhere from the solenoid actually sticking to the tranny is shelled.
So cleared it, and all symptoms immediately went away. Ran perfect.
Today, coming home from the same place (I go every Wednesday) I've been watching it now, so I noticed when it happened. I came off the highway to a stop. I didn't notice it revving too much when I shifted, but noticed immediately after accelerating lightly that it was turning too many RPM's for the speed again.
Tested right then while driving. P0741. Cleared it while driving. RPM's immediately dropped to where they should be, ran perfect all the way home. Fluid still not too dirty, not smoked.
Oh, and my Wednesday customer is a dealership where there's a GM tech, he checked the fluid while I was there and also agreed it's not burnt and not excessively dirty.
So what am I seeing here? Is the converter getting ready to join the Church Triumphant? Is my TCC solenoid just actually sticking and maybe I should change the fluid? Something in between those two extremes?