Had this one in couple of days ago for ABS/VSC light on, the DTC logged in ABS/VSC system stated - "ECM fault", permanent fault.
The engine MIL was also on and "B1S1 O2 heater circuit fault" logged.
The customer is a regular mechanic that comes to me but always works at 100mph, does not want to spend on diagnostic time to confirm the cause of the fault and so just throws parts at the job hoping it will fix it.
Well he rushed off and bought s/h ABS unit, fitted it and the fault is still present, it would clear but return within about 10 seconds.

I persuaded him to replace the faulty O2 sensor and he returned to have the O2 code cleared whereupon I was able to clear the ABS/VSC "ECM fault" and it has not returned.

Now, I took the ECM to mean Electronic Control Module for the ABS/VSC system but it looks like it was actually Engine Control Module.

I was somewhat surprised to see that an O2 sensor could have such an effect on the ABS/VSC system - can anyone explain this please?

Thanks, Martin.