2013 SIERRA 6L80e p0741 CODE. CONVERTER NOT LOCKING.

[RyanCumuze]

Just some quick info.
New 6l80e trans
tcm os is 24265260
ecm os is 12653674
i programmed the tcm, OS was different.
External Trans Cooler.
Fluid has never looked bad or anything weird.
New pro torque billet triple disc 3800 stall converter.
New pro torque billet flexplate.
drove it 6 months with everything working correctly.
One night while normal driving it threw the p0741 code and unlocked the converter. Since then i cant get the converter to lockup. Code wont go away either. Ive swapped the trans for another brand new 6l80e, i bought 2 at once, because i tested the valve body solenoids, all checked out good. I tested the regulator valve and it works. The only other 3 things it could be is converter itself, tcm itself, and the control valve in the pump. So i got another brand new converter and swapped the trans and converter at the same time to cross out the control valve in the pump and the converter as the issue. The tcm is the only thing left that i havent swapped. But from what i can tell the tcm isnt doing anything it isnt suppose to. Its working correctly. It has the correct os that matches the factory ecm os. Ive tried commanding the pwm with the scanner and it doesnt lockup. What could be the issue? Because im stumped. Keep in mind. Same problem between 2 different transmission(new), 2 different new converters. The only thing that has stayed the same between the two is the TCM itself. Which is why i think its the TCM. The TCM in the 2nd transmission would never read for some reason like it was bricked. So i took the TCM off the 1st new trans and put it on the valve body of the 2nd new trans. Im convinced its the TCM. With everything ive read my ECM OS 12653674 is only compatible with the TCM OS 24265260. Aynybody else had this issue.

[TransGo Robert]

Just some quick info.
New 6l80e trans
tcm os is 24265260
ecm os is 12653674
i programmed the tcm, OS was different.
External Trans Cooler.
Fluid has never looked bad or anything weird.
New pro torque billet triple disc 3800 stall converter.
New pro torque billet flexplate.
drove it 6 months with everything working correctly.
One night while normal driving it threw the p0741 code and unlocked the converter. Since then i cant get the converter to lockup. Code wont go away either. Ive swapped the trans for another brand new 6l80e, i bought 2 at once, because i tested the valve body solenoids, all checked out good. I tested the regulator valve and it works. The only other 3 things it could be is converter itself, tcm itself, and the control valve in the pump. So i got another brand new converter and swapped the trans and converter at the same time to cross out the control valve in the pump and the converter as the issue. The tcm is the only thing left that i havent swapped. But from what i can tell the tcm isnt doing anything it isnt suppose to. Its working correctly. It has the correct os that matches the factory ecm os. Ive tried commanding the pwm with the scanner and it doesnt lockup. What could be the issue? Because im stumped. Keep in mind. Same problem between 2 different transmission(new), 2 different new converters. The only thing that has stayed the same between the two is the TCM itself. Which is why i think its the TCM. The TCM in the 2nd transmission would never read for some reason like it was bricked. So i took the TCM off the 1st new trans and put it on the valve body of the 2nd new trans. Im convinced its the TCM. With everything ive read my ECM OS 12653674 is only compatible with the TCM OS 24265260. Aynybody else had this issue.

Definitely sounds like a stuck closed solenoid in that TEHCM.

[Alvin]

If the speedo calibration isn't the same between ECM and TCM you can run into this.