List Of All Engine Fault Codes
Engine trouble codes are divided into 4 parts based on the vehicle system affected. These codes start with P, U, B, and C — each covering a different diagnostic area.
Powertrain Codes
Engine, transmission, fuel system and emissions. The most common fault category.
P0300, P0420, P0171…Network Codes
Vehicle communication bus, module-to-module data errors and CAN network faults.
U0001, U0100, U0121…Body Codes
Airbags, climate control, power windows, seats and interior electronics.
B0001, B0020, B1200…Chassis Codes
Brakes, ABS, traction control, steering and suspension systems.
C0035, C0110, C1200…We cover more than 20,000 engine trouble codes across all four OBD-II categories. Select a category above to browse the full list, or use the search box to jump directly to any code.