I currently have a 2020 RAM 2500 with the 68FRE.

I was driving down the highway this morning in 6th gear, got on it to merge over, and heard a weird whining sound coming from what seemed to be the transmission.

Then shortly after, the engine light came on.

I scanned the code and got code P0729 (Gear 6 Incorrect Ratio).

Then I drove the truck around, and everything seemed fine.

It was shifting like it usually does and going through all six gears without any issues.

The truck has 40,000 miles on it and is not ragged.

I checked the transmission fluid, and it was at a normal level.

The noise from the transmission happens when the engine is under load at high RPM in the 5th/6th gear.

I just was wondering if anyone had any insight on what is wrong.

Or if anyone has had the same issue before.

Thanks.