GROM w/o audio signal - Redstar DSP amp w/o coax DSP connection

[drewski429]

This is my second Z4 roadster so I added an AUX jack under the climate control on the first day I had the car, and it has factory bluetooth phone functions but not streaming, yada yada yada I bought the GROM with bluetooth.

Same story as everyone. BUT, my newest Z4, a 2006 3.0si is something odd. I have DSP, like my old one, Business CD, like my old one, and I successfully found the pair of connectors in the trunk for the CD Changer to hook into the GROM, but there is no Coaxial cable or jack anywhere for DSP wiring, it is "integrated" on the Redstar DSP amp. There is no coaxial on the head unit, none hidden under the center box where the CDC wire was... just baffling.

So. GROM says just hook it in and go. I get track titles and the steering wheel controls do things, but there is no sound. what. the. crap.

Open up my ISTA/P version 3.55.0.300, I'll show you, CAR!
CDC already coded? OK, then. It's in the VO display box as installed. Hmm, so I go through the service actions to "replace" the CDC module, while the GROM is hooked in, run it, successful report...

No. Sound.

What am I missing here? 672 is coded in. Someone mentioned 692, or an MP3 coding option, but I don't think that applies to the E85 facelift 3.0si models... the car is LW91850 if anyone wants to help out. I have never tried the WinKFP route yet, and don't know if I'll brick the car.