researching 2 KOMBI (and 2 DME) fault codes that are always present

[workingonit]

I've mentioned that I've got two "always present" fault codes that won't clear. My Foxwell shows them as:
actual fault names, undisclosed

So, I've been researching about what the Foxwell letter codes BD & D7 actually mean. I found no reference to them in any Foxwell or (limited) BMW info I have (not even a Bentley), but I did find info via the internet, on various BMW enthusiast sites. The most useful reference to those letter codes was found in some notes I had compiled prior to even getting the X5. I had a list of what I called "KOMBI codes".

Where I found it originally, I don't know when, or where, or from whom. It does agree with another list I found on Bimmerfest:https://www.bimmerfest.com/threads/i.../post-13259319

Using that list (and the BMW abbreviations list from https://bmwsections.com/info/abbreviations.php, I did more searching, decided that : BD Electronic brake power on my list actually referred to EBV - Electronic Brake force proportioning, and found this thread https://xoutpost.com/bmw-sav-forums/...ebv-fault.html right here on XO.

As far as they could tell, and I tend to agree, it's a phantom, since I have no brake light lit up on my dash.

Then there's the D7 fault code:D7 Fuel tank sensor 2 (without fuel pump) There's a lot of references to it on XO, including this 18-page AWR-fix thread https://xoutpost.com/bmw-sav-forums/...p-details.html, and dozens more on other sites. D7 may be another phantom code, but it probably ties into my recurring P0171, P0174, & P0313 codes. Since all these point to lean conditions, might it also be partially caused by poor fuel flow? I still can't find any vacuum leak.

Finally, I've just gotten two DME codes, D3 (DME Fuel trim bank 1 permissable range exceeded) & D4 (DME Fuel trim bank 2 permissable range exceeded), that are easier to decode (using Peake reader charts...it seems that Foxwell copied from them while programming)https://www.e46fanatics.com/threads/...e3-e4.1032009/ They are the result of the over-enrichening the fuel system is doing to overcome the lean codes, past "plausible" limits.

I may be starting to see the convoluted "big picture" that may be a long-term project to fix. My X5 is now parked for the duration, since it seems to be a progressive disease...I don't want to damage either the engine or catalytic converters. I dusted-off my '04 Chevy 2500HD, and it's now my go-to, again. Damn.