It's not always the ABS module

[850oldschool]

My personal favorite. "I just picked up this sweet Volvo for $500, the seller said all it needs is an abs module". When I hear that I know the car is a $2k FCP order away from being just OK. It's also loaded with butt connectors, zip ties, rtv all over and a mirror full of air fresheners to cover the smell of 500 cartons of cigarettes.

I got my butt kicked in a BMW E83 this Spring

With a new job in NYC SWMBO favourite non-Volvo car had a nice habit of kicking into limp mode 20 minutes after getting to highway speed. Nasty

I chased ignition and fuel and finally found a rusty tone ring on right rear , which was shutting off the ECU. Not a single code was set. Finally tracked it down with real time wheel speed data , seeing noise on the signal on that wheel.

Were you looking at the digital or analog signal? Irregular voltage waveforms, or erratic ones and zeros?

[abscate]

Digital waveforms on a scanner. The data is analog but it’s sampled at 1hz or so

The right rear wheel showed a lot more modulation, about 5% of the signal than the others. New tone ring cleaned it up and eliminated the loss of power issue

[850oldschool]

Were you scanning that through the OBD2 port?

[abscate]

Were you scanning that through the OBD2 port?

Yes, via an AUTEL 812? Scanner with a module for BMW specific codes