2004 S60 2.5T AWD, ABS Brake Failure warning

[mkbell2000]

2004 S60 2.5T AWD, 95k miles.
I get the Brake Failure-Stop Safely on my dash. The odometer displays '----'. Other gauges work fine. This now happens consistently when the car starts, or shortly after driving.

I am a little confused on repair options. I saw older models have issues with cold solder joints, and posts about removing the ABS controller and sending it out for repair or steps to try it yourself. But all that info seems to be for older models.

I believe this model has a brake control module, which doesn't seem to have rebuild/DIY options. Xemodex offers $400 rebuilds, I also found AutoECU.com offers this:

2002Chassis Control Box(not Engine)Volvo 70 Series R&R REBUILD REPAIR YOU SHIP TO US-RBL;T RR $189 +$22.50 UPS Ground*

Looking for some feedback:
1. Anything else I should try/check?
2. Will Volvo dealer code-reader tell me that it is definitely something wrong with the controller, vs wheel sensor or other simpler issue?
3. Are there DIY repairs possible on this unit?
4. I saw plenty of posts about xemodex but none about autoecu. The price is much nicer, but wonder what they do for this vs what xemodex does.

Thanks in advance!
Malcolm