Ran through the steps of the diagnostics. Seems like the end game is either to replace the TCBP/CACT sensor or to replace the ECU. I already threw a TCBP/CACT sensor at it, so we'll see what happens. It's an intermittent problem, so probably won't know for sure for at least a week or so.
I'd like to do the pressure readings, but not exactly sure how.