TL;DR -- I see tables of FF 01 through 10 and maybe 11. What is FF 12?

I've been chasing down a previously intermittent problem where my Mini would blow very hot air for a brief period of time, especially when the temperature set on the IHKA was around that of outside air. Another symptom was that I needed to set the temperature into the 60s F to get cool air. I bought spare sensors and a blend-flap actuator only to find out that most require the dash to be disassembled to replace. Just recently, the A/C gave out entirely, with no cold air at all on any setting. Before throwing money at a new clutch, compressor or more, I wanted to find out what might be the cause of the original problem.

Nothing that I can find shows up with either my old Peak OBD tool or using the OBDLinkMX+ (MX201) and its iPhone software that we have.

I found the description of the IHKA test mode and FF 01 through FF 10 at https://www.northamericanmotoring.co...a-c-issue.html (Post #8) as well as the substitution of the A/C "snowflake" button for the "OFF" actuator not present on later versions of the control in Post #17 of that thread.

Stage 1 tests indicate a FF 12, which I have not been able to identify.
Stage 2 initiates and completes the calibration, which does not clear the FF 12

https://www.northamericanmotoring.co...mmon-item.html lists
09 motor- air distribution flap
011 motor- temp mixing flap
though that seems inconsistent with "10 Blend flap servomotor fault"

Any idea what the FF 12 code indicates?

Other suggestions for affordable diagnostic tools are welcome. Please PM if off topic.
Edit: I found an old laptop and will be trying to run INPA once the cable arrives.