OBD-II Diagnostic Trouble Codes Directory
Browse our complete database of 9,317 check engine codes, organized by vehicle system and monitored subsystems.
Powertrain Systems (P-Codes)
Powertrain diagnostic codes cover malfunctions in the engine, fuel delivery system, air intake, ignition, transmission, and hybrid propulsion systems.
Fuel & Air Metering and Auxiliary Emission Controls
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Fuel & Air Metering (injector circuit)
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Ignition System / Misfire
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Auxiliary Emission Controls
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Vehicle Speed / Idle Control / Aux Inputs
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Computer Output Circuit (PCM/ECU)
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Transmission
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Hybrid Propulsion
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Hybrid/EV Propulsion (extended)
Monitors circuit failures, sensor values, and mechanical faults within this powertrain subsystem.
Body, Chassis & Network Systems (B, C, U Codes)
Browse diagnostic trouble codes for passenger compartment electronics, braking systems, active suspension, and controller area network (CAN) communication systems.
Body (System B)
Covers electronic control networks, wiring connector faults, safety systems, and chassis actuators.
Chassis (System C)
Covers electronic control networks, wiring connector faults, safety systems, and chassis actuators.
Network/Communication (System U)
Covers electronic control networks, wiring connector faults, safety systems, and chassis actuators.