OBD-II trouble codes

Ranked by how often the code appears in real NHTSA owner complaints - not alphabetically. P = powertrain, B = body, C = chassis, U = network.

Browse by symptom

Rough idle / shaking Stalling Hard starting Hesitation / power loss Flashing check engine light Poor fuel economy Shifting problems Temperature / cooling ABS / dashboard lights

Codes whose typical symptoms include hesitation / power loss - most serious first:

P0016Crankshaft Position - Camshaft Position Correlation Bank 1 Sensor A P0121Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance P0122Throttle/Pedal Position Sensor/Switch A Circuit Low P0123Throttle/Pedal Position Sensor/Switch A Circuit High P0300Random/Multiple Cylinder Misfire Detected P0301Cylinder 1 Misfire Detected P0601Internal Control Module Memory Checksum Error P0605Internal Control Module Read Only Memory (ROM) Error P0606Control Module Processor P0607Control Module Performance U0101Lost Communication With TCM P0011A Camshaft Position - Timing Over-Advanced or System Performance Bank 1 P0012A Camshaft Position - Timing Over-Retarded Bank 1 P0021A Camshaft Position - Timing Over-Advanced or System Performance Bank 2 P0101Mass or Volume Air Flow Sensor A Circuit Range/Performance P0102Mass or Volume Air Flow Sensor A Circuit Low P0106Manifold Absolute Pressure/Barometric Pressure Sensor Circuit Range/Performance P0171System Too Lean Bank 1 P0174System Too Lean Bank 2 P0700Transmission Control System (MIL Request)P0750Shift Solenoid A P0133O2 Sensor Circuit Slow Response Bank 1 Sensor 1 P0325Knock/Combustion Vibration Sensor A Circuit P0332Knock/Combustion Vibration Sensor B Circuit Low P0420Catalyst System Efficiency Below Threshold Bank 1