DTC C2111: Brake Fluid Pressure Sensor Power Supply Circuit (Low input); DTC C2112 Brake Fluid Pressure Sensor Power Supply Circuit (High input): Operation
WARNING: This page is about a different car, the 2015 Mitsubishi Lancer. However, it is still accessible from the selected car via links, so may be relevant.
When the brake pedal is depressed, the brake fluid pressure sensor integrated in the hydraulic unit detects the brake fluid pressure applied from the master cylinder, converts the pressure value into voltage signal, and outputs it.