If I don't see anything in the Button Codes Display when I hit a remote key, does that definitely mean that the empeg can't receive that remote's carrier frequency? Or is there some possibility that it might still be able to? I know I'm probably grasping at straws, but I really, really want this to work.

BTW, it's a Sony RM-X117 remote for the CDX-M630 head unit. Actually I'll be using an SWI-X unit to get the steering wheel controls to work, but it should be the same thing (I want the empeg to react to the SWI-X output when it's emulating the Sony head unit remote buttons).

The only alternative I can see is to have the resistance seen by the SWI-X change when the empeg is active (to make it give me a whole other set of codes). This would require some basic transistor circuit being (de)activated when the empeg is active. The drawback to this is that I'd bump into the limit of 12 codes generated by the SWI-X, and it's a bit of pain, but it should work. Any other ideas are most welcome.