a1smith

The BCM is basically the same for all trucks in the same model year; they are not VIN specific. The code in the BCM is also not VIN specific. What is VIN specific is the calibrations in the BCM - they are set for the specific options in your vehicle. So you will need to get the BCM reflashed where they enable the RPO code for the seat heaters. Also, IIRC, there is also a local seat heater controller that is under the seat - I'm pretty sure the BCM is talking to the seat heater controller over the LIN bus. The seat heater controller is not VIN specific, it is specific to that seat.

@Grumpy Bearhas a nice post discussing torque converter issue and more reliable replacement.

The torque converter clutch facing is a carbon fiber weave material that is black (same color as the fluid here.) The P0741 DTC you had before is TCC circuit stuck off which turns on if the TCM is trying to control slip on the TCC and nothing happens (high slip error). It could be that your cooler was plugged with a bunch of TCC facing material - the first place the oil goes once it leaves the torque converter is the cooler. The high temps could be the TCC trying to control slip but it is metal to metal now. If this "hypothesis" is right then you need to immediately stop using the transmission - any further use will just send more metal particles all over the transmission (solenoid valve screens, range clutch facings, spool valve bores, etc) and guarantee a needed rebuild. It may already be too late.

Here is another article that complements the Sonnax article; it has more information on the waviness of the cover's clutch surface along with some nice pictures. https://gearsmagazine.com/magazine/another-problem-with-the-6l80-90-converter/

Does anyone have an idea of what the failure rate is? If it is very high (-> 100%) then it seems that replacing the torque converter before failure with the 77-JMBXSD Grumpy Bear mentioned is the less expensive option. With a lower failure rate maybe it's worth waiting to see if it will happen or not - but Murphy's law says it will happen on a camping trip with 5000# trailer out in the middle of nowhere.