Need Help/Advice with the ABS/DSC Trifecta Light

[stymes01]

I know, another thread on this topic. I have read much of what is out there on this issue. I am looking for advice from those here who seem to know so much about this issue specifically given my symptoms. I have been chasing this down for a while and can't afford to pay the shop with a baby on the way and also have some interesting symptoms which are a little out of the ordinary. I am decently competent shade tree mechanic but do not have a BMW specific scan tool.

First let me give symptoms- The trifecta lights come on at 20 miles per hour or when you floor it. Under this speed everything works normally. I originally though pre-charge pump and ordered a used one. Upon closer inspection I determined it was a bitch to change and made sure to test it first. Upon putting 12v's to the pump it seemed to be working just fine and sounded strong. The car had a $2500 brake job before I bought it at NTB and they did master and calipers I believe. I have no issues with cruise or speedo. My OBC button does't cycle but I think this is the button.

After the pre-charge pump seemed good I sent the ABS module off to BBA reman to be rebuilt. No change. I then replaced all 4 wheel speed sensors (yes with crappy aftermarket sensors) Then in the winter once our roads were snow covered an interesting thing happened. After cycling the ABS maybe 15-20 times the ABS light turned off and just the DSC/Brake light stayed. This time the Brake light was red. Upon inspection I found the brake system to be low on fluid. My working theory was an air bubble trapped in the ABS module that was pumped out after enough cycling of the system and I thought the lights were maybe due to low fluid. Not sure how the reservoir went low but at this point I bled the brakes the old fashioned way. Well I ran the reservoir dry by accident and pumped air into the system. So in to a very reputable Indy she went for a good professional brake bleed using the ABS. I just got her back and have the same symptoms. I don't believe the aftermarket sensors are a problem because the ABS was working properly for quite a while in the winter and always under 20mph before the triefecta lights come on.

I am hoping someone can take these symptoms and pin point a likely next culprit for me. Specifically I am wondering if it could be brake pressure sensor? but I read I would more commonly have the DSC light a long with the brake light but not necessarily the ABS light. Thanks in advance