With the forums help I've got the click-clack sounds figured out on my PFE Sound Reefer and have moved on to the more advanced features. The manual says to get the most out of it you should create a train. All of my engines are TMCC. There isn't a Legacy engine amongst them. I didn't think this would matter, or should matter. But apparently it does.
First I tried to create Train #11 on the Cab2. I didn't get a horn blast from my Lionmaster Challenger (year 2000ish) when I tried to program this on the Cab2. But then I recalled something about TMCC not being able to go beyond 9 on some ID types. So I cleared Train #11 and created a Train #7. I added the Lionmaster Challenger and the PFE Reefer to the train and when the Cab2 read "programming trains" I did get a horn confirmation from the Challenger and a confirmation from the PFE Reefer.
However, this "marriage" between a TMCC Challenger and Legacy Reefer seems to play havoc with the TMCC engine part of the combo. I was finding the Challenger unresponsive. If I selected ENG, the ID# and INFO on my CAB2 and SCROLLed I found the Challenger's TMCC setting switched from TMCC to LEG and on the RAILSOUNDS screen it had gone from RS to either RS5 or LRS (I forget which). If I moved TMCC mode back to TMCC and RAILSOUNDS mode back to RS the engine would respond again. However, it seems as if any Railink activity on that Train accessing the PFE Reefer would then switch the engine settings back on the Challenger to the incorrect values once again rendering the engine unable to be controlled with the Cab2.
Perhaps Lionel didn't expect folks to be creating "Trains" between Legacy cars and TMCC engines. You would think the Cab2 code could be smart enough to deal with this, or at least could be made smart enough in a subsequent release. Or am I just doing something wrong?