TCM / PCM replacement

[sunrisew]

I've been having what I thought was transmission problems--once warmed up, my 2005 KJ slips out of gear at intersections and then can lurch into gear, sometimes causing a stall. And on a recent road trip it suddenly would not shift above second on the highway. I hooked up a diagnostic tool and got codes P0846, P0700, P0731, P0841, and P1776. Resetting everything helped temporarily. I had the transmission serviced, and all is fine mechanically. From what I've been able to read, I seem to need a new TCM, which apparently is part of the PCM on the 2005 model. Is this just a simple matter of switching out the PCM, and does it then need to be flashed by the dealer, or is it just a matter of ordering and installing it? Any tips or advice?

 

[sunrisew]

Adding a follow-up here. I did swap the TCM/PCM and there was no improvement. Returned that unit. It turns out the torque converter was trashed even though there were no metal filings in the transmission pan, so I had a transmission rebuild done, and all is well.