It is a "C" in front of the number, which means the error code C1050 indicates a problem with the ABS (Anti-lock Braking System) wheel speed sensor. Here is a guide to help you test the sensors and the location of the sensor in the images below.
Repair Safety Notice: This information is for general instructional purposes only. Vehicle repair can be dangerous. Verify all information, follow manufacturer service procedures, use proper tools and safety equipment, and consult a qualified repair shop when needed.