OBD-II code library
OBD-II codes: understand them before you repair
Each code has the standard definition, common causes, symptoms, checks in a sensible order and advice on whether to keep driving. These are generic codes that mean the same on every make.
80 codes
Variable valve timing and engine timing
Fuel and air metering
- P0087Fuel Rail/System Pressure - Too LowHigh
- P0101Mass or Volume Air Flow Circuit Range/PerformanceMedium
- P0102Mass or Volume Air Flow Circuit Low InputMedium
- P0103Mass or Volume Air Flow Circuit High InputMedium
- P0106Manifold Absolute Pressure/Barometric Pressure Circuit Range/PerformanceMedium
- P0107Manifold Absolute Pressure/Barometric Pressure Circuit Low InputMedium
- P0108Manifold Absolute Pressure/Barometric Pressure Circuit High InputMedium
- P0171System Too Lean (Bank 1)Medium
- P0172System Too Rich (Bank 1)Medium
- P0174System Too Lean (Bank 2)Medium
- P0175System Too Rich (Bank 2)Medium
Engine sensors
- P0112Intake Air Temperature Sensor 1 Circuit LowLow
- P0113Intake Air Temperature Sensor 1 Circuit HighLow
- P0121Throttle/Pedal Position Sensor/Switch A Circuit Range/PerformanceMedium
- P0122Throttle/Pedal Position Sensor/Switch A Circuit LowMedium
- P0123Throttle/Pedal Position Sensor/Switch A Circuit HighMedium
- P0325Knock Sensor 1 Circuit (Bank 1 or Single Sensor)Low
- P0335Crankshaft Position Sensor A CircuitHigh
- P0336Crankshaft Position Sensor A Circuit Range/PerformanceHigh
- P0340Camshaft Position Sensor A Circuit (Bank 1 or Single Sensor)Medium
- P0341Camshaft Position Sensor A Circuit Range/Performance (Bank 1 or Single Sensor)Medium
Cooling system
- P0116Engine Coolant Temperature Circuit Range/PerformanceMedium
- P0117Engine Coolant Temperature Circuit LowMedium
- P0118Engine Coolant Temperature Circuit HighMedium
- P0125Insufficient Coolant Temperature for Closed Loop Fuel ControlLow
- P0128Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)Low
- P0217Engine Coolant Over Temperature ConditionHigh
- P0480Cooling Fan 1 Control CircuitMedium
Emission control
- P0131O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)Medium
- P0133O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)Medium
- P0134O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)Medium
- P0135O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)Medium
- P0137O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)Low
- P0141O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)Low
- P0401Exhaust Gas Recirculation Flow Insufficient DetectedMedium
- P0402Exhaust Gas Recirculation Flow Excessive DetectedMedium
- P0403Exhaust Gas Recirculation Control CircuitMedium
- P0420Catalyst System Efficiency Below Threshold (Bank 1)Medium
- P0430Catalyst System Efficiency Below Threshold (Bank 2)Medium
Turbo and boost
Ignition and misfire
- P0300Random/Multiple Cylinder Misfire DetectedHigh
- P0301Cylinder 1 Misfire DetectedHigh
- P0302Cylinder 2 Misfire DetectedHigh
- P0303Cylinder 3 Misfire DetectedHigh
- P0304Cylinder 4 Misfire DetectedHigh
- P0305Cylinder 5 Misfire DetectedHigh
- P0306Cylinder 6 Misfire DetectedHigh
- P0307Cylinder 7 Misfire DetectedHigh
- P0308Cylinder 8 Misfire DetectedHigh
- P0351Ignition Coil A Primary/Secondary CircuitHigh
- P0380Glow Plug/Heater Circuit AMedium
Evaporative emission (EVAP)
- P0440Evaporative Emission SystemLow
- P0441Evaporative Emission System Incorrect Purge FlowLow
- P0442Evaporative Emission System Leak Detected (Small Leak)Low
- P0443Evaporative Emission System Purge Control Valve CircuitLow
- P0446Evaporative Emission System Vent Control CircuitLow
- P0455Evaporative Emission System Leak Detected (Large Leak)Low
- P0456Evaporative Emission System Leak Detected (Very Small Leak)Low
- P0457Evaporative Emission System Leak Detected (Fuel Cap Loose/Off)Low
Speed and idle control
Electrical and control module
Transmission
Network communication
General reference information. It does not replace a diagnosis on your own vehicle. The same code can have different causes depending on make, model year and engine; check the manufacturer's documentation or ask a technician with a scan tool.