2010 Prius uneven rotor wear and brake codes

200k miles, the drivers side rear rotor has only a narrow contact point with the brake pads and the rest of the rotor is rusty. All other rotors are clean. I am getting traction control light, brake light, abs light. DTCs of C0210, C1238, C1214. I know that they are for speed sensors and master cylinder. The pressure behind the brake pedal feels good and the fluid level is not diminishing. I replaced the speed sensors, or at least the wires leading to them, I am not really sure if the actual sensor is inside the hub or at the end of that wire. The brakes seems to be performing well so I am hoping it is not master cylinder.

Main question is: is the uneven brake pad pressure possibly causing these codes? How can i get that brake functioning properly? What is the best way to find the actual problem?