Well, I hadn't planned to install the HD ACM until today but, since I was doing a firmware upgrade to the Pioneer unit in my Ranger yesterday, while unzipping the file needed for that, I spent the 5 minutes it took to install the HD ACM. I also mentioned before, I would have pics of the insides of both non and HD units and here they are. If you carefully observe, there is a difference as the HD ACM has an extra piece of electronics in an area that the other ACM does not. It must be the HD magic box! It also looks like they made it impossible to add that piece to the standard unit as well. Anyway, you can see that they are mainly unremarkable in their content. Just another car stereo unit.
If you are interested in doing this swap, those forscan spec sheets are the key to getting the unit to work correctly. Now, the next thing I want to examine is adding the DSP amp and getting those other features like EQ, DSP surround and such to work properly. I don't really care about that stuff, I just like tinkering.
One of the interesting things about this new HD ACM addition is the inclusion of the VIN from the vehicle it came from. A '15 Explorer Limited with the Sony system, apparently. This answers a basic question I wondered about as to what ACM they are using for the Sony system. But, also brings up another question. The ACM used is not built by Sony so, what is 'Sony' in this system and how do they get to claim it is a Sony system? The answer that I come up with is the DSP amp that is used. It says 'Sony' on it so, I guess they get to call the top of the line audio system 'Sony'.
Look, I don't know how many of you are really interested in solving the ability to upgrade your lesser audio systems using what's available from Ford. If it's possible to upgrade these systems to get close to the top of the line, that's my interest. I'm not as interested in getting a better system more than it is to finding out if it can be done. As far as I'm concerned, My 'lesser' system was just fine. I just think that if one is able to upgrade to the Sony system with the addition of the HI4 ACM and adding the Sony DSP amp, using, what I believe to be, the already installed wiring harness that I believe to be universal to all the audio systems, this 'mystery' can be solved. So, far, it seems my research is heading in that direction.