The next day he came back and the motor passed the TECMate Pro test. After having a frustrated tech work for three hours trying to track it down (along with calling in a coworker for another hour or so.) he ordered a TECMate ECM tester (which he surprisingly didn’t have) and said he’d be back the next day. After the swap it had the exact same code errors, so I called my local Bryant dealer. Since I had some initial seemingly random codes flashing when the problem first occurred, I took a calculated risk and bought a new variable speed board (HK42FZ012) and replaced that. The house ducting has not been changed and I completely removed the filter for this testing so there shouldn’t be an issue there. When I ran the component test it flashed the 41 code (Blower Outside Valid Speed Range). The fan started working, but it kept flashing the 44 code (Blower Calibration Fault). I picked up a used/tested ECM module (RMOD52AE120) on eBay and installed it. I took the 1 HP blower motor (HD52AE120) apart and found a capacitor fried to the thermister in the ECM.
I have a 14 year old Bryant Plus 90i 355MAV that had blower issues the day after a neighborhood power outage.
