OBD-II Fault Codes
Look up a code from your scanner. Every code page shows the risk first, then what it means, possible causes and how it is diagnosed.
Codes and titles follow SAE J2012 · Maker notes verified per make and engine · How we verify
Browse by system
Powertrain codes by subsystem
P00xxFuel, air metering and auxiliary emission controlsP01xxFuel and air meteringP02xxFuel and air metering (injector circuit)P03xxIgnition system and misfireP04xxAuxiliary emission controlsP05xxVehicle speed, idle control and auxiliary inputsP06xxComputer and auxiliary outputsP07xxTransmissionP2xxxAdditional generic codes (fuel, air, emissions)
Most searched codes
P0420Catalyst System Efficiency Below Threshold (Bank 1)Normal riskP0300Random/Multiple Cylinder Misfire DetectedHigh riskP0171System Too Lean (Bank 1)Normal riskP0128Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)Normal riskP0455Evaporative Emission System Leak Detected (Large Leak)Normal riskP0401Exhaust Gas Recirculation "A" Flow Insufficient DetectedNormal riskP0442Evaporative Emission System Leak Detected (Small Leak)Normal riskP0700Transmission Control System (MIL Request)Normal riskP0299Turbocharger/Supercharger "A" Underboost ConditionNormal riskP0172System Too Rich (Bank 1)Normal riskP0135O2 Sensor Heater Circuit (Bank 1 Sensor 1)Normal riskP0113Intake Air Temperature Sensor 1 Circuit HighNormal risk
How to read a fault code
The letter is the system, the first digit says generic or maker-specific, the next digit the subsystem and the last two the exact fault. Fault Code Lookup →All fault codes
P0151O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)Normal riskP0152O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)Normal riskP0153O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)Normal riskP0154O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)Normal riskP0155O2 Sensor Heater Circuit (Bank 2 Sensor 1)Normal riskP0156O2 Sensor Circuit (Bank 2 Sensor 2)Normal riskP0157O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)Normal riskP0158O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)Normal riskP0159O2 Sensor Circuit Slow Response (Bank 2 Sensor 2)Normal riskP0160O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)Normal riskP0161O2 Sensor Heater Circuit (Bank 2 Sensor 2)Normal riskP0162O2 Sensor Circuit (Bank 2 Sensor 3)Normal riskP0163O2 Sensor Circuit Low Voltage (Bank 2 Sensor 3)Normal riskP0164O2 Sensor Circuit High Voltage (Bank 2 Sensor 3)Normal riskP0165O2 Sensor Circuit Slow Response (Bank 2 Sensor 3)Normal riskP0166O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 3)Normal riskP0167O2 Sensor Heater Circuit (Bank 2 Sensor 3)Normal riskP0170Fuel Trim (Bank 1)Normal riskP0171System Too Lean (Bank 1)Normal riskP0172System Too Rich (Bank 1)Normal riskP0173Fuel Trim (Bank 2)Normal riskP0174System Too Lean (Bank 2)Normal riskP0175System Too Rich (Bank 2)Normal riskP0190Fuel Rail Pressure Sensor "A" CircuitHigh riskP0191Fuel Rail Pressure Sensor "A" Circuit Range/PerformanceHigh riskP0192Fuel Rail Pressure Sensor "A" Circuit LowHigh riskP0193Fuel Rail Pressure Sensor "A" Circuit HighHigh riskP0194Fuel Rail Pressure Sensor "A" Circuit IntermittentHigh riskP0200Injector Circuit/OpenHigh riskP0201Injector Circuit/Open – Cylinder 1High riskP0202Injector Circuit/Open – Cylinder 2High riskP0203Injector Circuit/Open – Cylinder 3High riskP0204Injector Circuit/Open – Cylinder 4High riskP0205Injector Circuit/Open – Cylinder 5High riskP0206Injector Circuit/Open – Cylinder 6High riskP0207Injector Circuit/Open – Cylinder 7High riskP0208Injector Circuit/Open – Cylinder 8High riskP0217Engine Coolant Over Temperature ConditionCritical riskP0220Throttle/Pedal Position Sensor/Switch "B" CircuitHigh riskP0221Throttle/Pedal Position Sensor/Switch "B" Circuit Range/PerformanceHigh riskP0222Throttle/Pedal Position Sensor/Switch "B" Circuit LowHigh riskP0223Throttle/Pedal Position Sensor/Switch "B" Circuit HighHigh riskP0230Fuel Pump Primary CircuitHigh riskP0231Fuel Pump Secondary Circuit LowHigh riskP0232Fuel Pump Secondary Circuit HighHigh riskP0234Turbocharger/Supercharger "A" Overboost ConditionHigh riskP0236Turbocharger/Supercharger Boost Sensor "A" Circuit Range/PerformanceNormal riskP0237Turbocharger/Supercharger Boost Sensor "A" Circuit LowNormal riskP0238Turbocharger/Supercharger Boost Sensor "A" Circuit HighNormal riskP0243Turbocharger/Supercharger Wastegate Solenoid "A"Normal riskP0245Turbocharger/Supercharger Wastegate Solenoid "A" LowNormal riskP0246Turbocharger/Supercharger Wastegate Solenoid "A" HighHigh riskP0261Cylinder 1 Injector "A" Circuit LowHigh riskP0262Cylinder 1 Injector "A" Circuit HighHigh riskP0264Cylinder 2 Injector "A" Circuit LowHigh riskP0265Cylinder 2 Injector "A" Circuit HighHigh riskP0267Cylinder 3 Injector "A" Circuit LowHigh riskP0268Cylinder 3 Injector "A" Circuit HighHigh riskP0270Cylinder 4 Injector "A" Circuit LowHigh riskP0271Cylinder 4 Injector "A" Circuit HighHigh riskP0273Cylinder 5 Injector "A" Circuit LowHigh riskP0274Cylinder 5 Injector "A" Circuit HighHigh riskP0276Cylinder 6 Injector "A" Circuit LowHigh riskP0277Cylinder 6 Injector "A" Circuit HighHigh riskP0279Cylinder 7 Injector "A" Circuit LowHigh riskP0280Cylinder 7 Injector "A" Circuit HighHigh riskP0282Cylinder 8 Injector "A" Circuit LowHigh riskP0283Cylinder 8 Injector "A" Circuit HighHigh riskP0299Turbocharger/Supercharger "A" Underboost ConditionNormal riskP0300Random/Multiple Cylinder Misfire DetectedHigh riskP0301Cylinder 1 Misfire DetectedHigh riskP0302Cylinder 2 Misfire DetectedHigh riskP0303Cylinder 3 Misfire DetectedHigh riskP0304Cylinder 4 Misfire DetectedHigh riskP0305Cylinder 5 Misfire DetectedHigh riskP0306Cylinder 6 Misfire DetectedHigh riskP0307Cylinder 7 Misfire DetectedHigh riskP0308Cylinder 8 Misfire DetectedHigh riskP0313Misfire Detected With Low FuelHigh riskP0316Engine Misfire Detected On Startup (First 1000 Revolutions)High riskP0324Knock Control System ErrorNormal riskP0325Knock Sensor 1 Circuit (Bank 1 Or Single Sensor)Normal riskP0326Knock Sensor 1 Circuit Range/Performance (Bank 1 Or Single Sensor)Normal riskP0327Knock Sensor 1 Circuit Low (Bank 1 Or Single Sensor)Normal riskP0328Knock Sensor 1 Circuit High (Bank 1 Or Single Sensor)Normal riskP0329Knock Sensor 1 Circuit Intermittent (Bank 1 Or Single Sensor)Normal riskP0330Knock Sensor 2 Circuit (Bank 2)Normal riskP0331Knock Sensor 2 Circuit Range/Performance (Bank 2)Normal riskP0332Knock Sensor 2 Circuit Low (Bank 2)Normal riskP0333Knock Sensor 2 Circuit High (Bank 2)Normal riskP0334Knock Sensor 2 Circuit Intermittent (Bank 2)Normal riskP0335Crankshaft Position Sensor "A" CircuitHigh riskP0336Crankshaft Position Sensor "A" Circuit Range/PerformanceHigh riskP0337Crankshaft Position Sensor "A" Circuit LowHigh riskP0338Crankshaft Position Sensor "A" Circuit HighHigh riskP0339Crankshaft Position Sensor "A" Circuit IntermittentHigh riskP0340Camshaft Position Sensor "A" Circuit (Bank 1 Or Single Sensor)Normal riskP0341Camshaft Position Sensor "A" Circuit Range/Performance (Bank 1 Or Single Sensor)Normal riskP0342Camshaft Position Sensor "A" Circuit Low (Bank 1 Or Single Sensor)Normal riskP0343Camshaft Position Sensor "A" Circuit High (Bank 1 Or Single Sensor)Normal risk