2010 prius abs brake traction lights on

Probably the master brake cylinder actuator

 

Somewhere, somebody probably has a car that needs the master brake cylinder actuator.

But this car is reporting ((!)) 36 (meaning look at the ABS code), and VSC 43 (meaning look at the ABS code), and ABS 34 (C0215, left rear speed sensor circuit).

So looking at the left rear bearing definitely sounds like the right track.

If you wanted to follow the C0215 troubleshooting steps in the repair manual, they would have you make some simple wiring and electrical checks before going straight to a bearing replacement.

Toyota Service Information and Where To Find It | PriusChat

If you don't have the means or desire to do that and just want to try the bearing and see if that takes care of it, the odds aren't too bad.

If things get rusty in 55044, be aware that the bearing job can be a workout.

 

I'll chime in here having just experienced this. I had similar codes for the right rear which Chapman also helped diagnose.
Bearing swap did the trick!
Couple of notes... Be careful unplugging the sensor (there are videos out there), order 4bnew hub bolts and be prepared to take the old ones out slowly and occasionally having to go back and forth to keep them from snapping. Lots of spray and possibly have access to a 12M x 1.25 thread tap to clean the holes out before installing the new hub. I also recommend lubing the caliper glide pins while you are in there.
Good luck!