Good idea to look at the live data of both pressure sensors. If their cables reach, try swapping them and see if the fault moves with the cable or stays with the sensor. We’ve seen bad DSC modules with internal discontinuity in signals such as wheel speed, brake pressure, and others.
You really want to isolate the bad part before replacing it.

Yeah, those sensors are stupid expensive. They were less than $50 just a few years ago. Used ones from a junkyard are probably $5 each!

BMW Pressure Sensor - Genuine BMW 23017568177

BMW Pressure Sensor - Genuine BMW 23017568177

www.fcpeuro.com

 

Flushed system, light went off for a about a day. INPA confirmed sensor 2 was showing +10 to what Sensor 1 had.

I ended up getting an amazingly clean used master cylinder out of a 2005 e46 with two sensors for $37.10 also got a power bleeder. Drained the fluid because there was no way to get the sensor replaced without removing the lines. (Not proud of getting a used part but the $200 was a little steep, the parts looked brand new so clean so I have taken a chance. If it goes again I will spring for the new part. Plus I have a decent Master Cylinder if i ever need it for the 2004 or 2005)

Replaced sensor, bled system using power bleeder and INPA to activate DSC. Learned alot as it was the first time bleeding brakes because I was always hesitant to touch (bleed) them given their criticality to keeping me alive. All is well, test drives and 3 days so far so good.

Lesson... FLUSH YOUR FLUIDS.... save the headache. The bleeder is only ~100.00 and you can use it on all your cars.

Now I need to find my other INPA cable, had to order a new one because I can not find it...

 

Now I need to find my other INPA cable, had to order a new one because I can not find it...

I have four different K+DCAN cables, because they’re cheap Chinese made with little quality control.
Helping folks on here remotely I see bad new cables often.