6l80 1-2 shift hangs

[Jarrod.v]

Hey guys, I have an 09 1500 silverado. I am experiencing a weird 1-2 shift. It will shift from 1st into 2nd, rpms will rev up, and then it feels like it shifts and locks into 2nd after that. It does it every time. Any ideas of how to correct this?

[5FDP]

Possible that a transmission relearn would fix that as well as resetting the adapts.

[Estep40511]

Have a look at your fluid level and condition. Very common that a possible check ball #6 is stuck in the valve body. They are made out of plastic and over time of banging against the metal of the valve body, they actually shrink.

[Alvin]

Possible that a transmission relearn would fix that as well as resetting the adapts.

I second this.. especially if in the tune the torque management has been turned off or turned back a lot or the pressures have been messed with.

[hjtrbo]

3rd this.

Also, the pressure switch films failing are starting to pop up a fair bit on you tube. They tear which causes leaks in the signal circuits.

[alabastarbastard]

how many miles on it?

[Tfoggy]

Look at your trans tables. make sure the 1-2 and 2-1 shifts are "correct" and check to see if
it is still tuned to enable lock up on your TC in 2nd gear.. You should disable TCC in 1-3 gears anyway

[Jarrod.v]

Thank you everyone for the replies! I have 187k miles on the tranny. I haven't found anything online to resolve any mechanical issues that may be causing this, but I also haven't had a lot of time to dig deep into it either. I will try the transmission relearn when I get back home Sunday from working out of town. I have checked the fluid level, and it is fine. It could probably go for a flush though. This morning my transmission felt "stuck". The shifter did not want to move, but eventually did without having to use force. It did that this morning, and this evening as we were leaving a job site. It may just be time to have it taken it and rebuilt.

[Jarrod.v]

I've done the transmission relearn and reset the adapts, no fix. The relearn fails at the end of the process too. Purges, calibrates, goes through it shifts, and fails. Tranny temp was over 175. No engine codes. Parking brake set, brake pedal pressed, and I even did the park to reverse three times before the test too. I tried resetting just the adapts too. I will reset them and drive around slowly, letting the shifts shift gradually. My 1-2 shift that I have the issue with disappears after the initial reset, but then returns later after a prolonged period. It is only the 1-2 shift that I have the issue with. Any ideas?

[STAGEUP]

Since no one has mentioned trans fluid,,,, have you checked fluid level? Make sure its a quart over full.