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
P0741Torque Converter Clutch Circuit Performance Or Stuck OffHigh riskP0742Torque Converter Clutch Circuit Stuck OnHigh riskP0743Torque Converter Clutch Circuit ElectricalNormal riskP0744Torque Converter Clutch Circuit IntermittentNormal riskP0750Shift Solenoid "A"Normal riskP0751Shift Solenoid "A" Performance/Stuck OffHigh riskP0752Shift Solenoid "A" Stuck OnHigh riskP0753Shift Solenoid "A" ElectricalNormal riskP0755Shift Solenoid "B"Normal riskP0756Shift Solenoid "B" Performance/Stuck OffHigh riskP0757Shift Solenoid "B" Stuck OnHigh riskP0758Shift Solenoid "B" ElectricalNormal riskP0760Shift Solenoid "C"Normal riskP0765Shift Solenoid "D"Normal riskP0770Shift Solenoid "E"Normal riskP0780Shift ErrorHigh riskP07811-2 ShiftHigh riskP07822-3 ShiftHigh riskP07833-4 ShiftHigh riskP07844-5 ShiftHigh riskP2002Diesel Particulate Filter Efficiency Below Threshold (Bank 1)Normal riskP2003Diesel Particulate Filter Efficiency Below Threshold (Bank 2)Normal riskP207FReductant Quality PerformanceHigh riskP2096Post Catalyst Fuel Trim System Too Lean (Bank 1)Normal riskP2097Post Catalyst Fuel Trim System Too Rich (Bank 1)Normal riskP2098Post Catalyst Fuel Trim System Too Lean (Bank 2)Normal riskP2099Post Catalyst Fuel Trim System Too Rich (Bank 2)Normal riskP20B9Reductant Heater "A" Control Circuit/OpenNormal riskP20EESCR NOx Catalyst Efficiency Below Threshold (Bank 1)Normal riskP2100Throttle Actuator Control Motor Circuit/OpenHigh riskP2101Throttle Actuator Control Motor Circuit Range/PerformanceHigh riskP2119Throttle Actuator Control Throttle Body Range/PerformanceHigh riskP2122Throttle/Pedal Position Sensor/Switch "D" Circuit LowHigh riskP2123Throttle/Pedal Position Sensor/Switch "D" Circuit HighHigh riskP2127Throttle/Pedal Position Sensor/Switch "E" Circuit LowHigh riskP2128Throttle/Pedal Position Sensor/Switch "E" Circuit HighHigh riskP2135Throttle/Pedal Position Sensor/Switch "A"/"B" Voltage CorrelationHigh riskP2138Throttle/Pedal Position Sensor/Switch "D"/"E" Voltage CorrelationHigh riskP2177System Too Lean Off Idle (Bank 1)Normal riskP2178System Too Rich Off Idle (Bank 1)Normal riskP2179System Too Lean Off Idle (Bank 2)Normal riskP2180System Too Rich Off Idle (Bank 2)Normal riskP2181Cooling System PerformanceNormal riskP2183Engine Coolant Temperature Sensor 2 Circuit Range/PerformanceNormal riskP2187System Too Lean At Idle (Bank 1)Normal riskP2188System Too Rich At Idle (Bank 1)Normal riskP2189System Too Lean At Idle (Bank 2)Normal riskP2190System Too Rich At Idle (Bank 2)Normal riskP2195O2 Sensor Signal Stuck Lean (Bank 1 Sensor 1)Normal riskP2196O2 Sensor Signal Stuck Rich (Bank 1 Sensor 1)Normal riskP2270O2 Sensor Signal Stuck Lean (Bank 1 Sensor 2)Normal riskP2271O2 Sensor Signal Stuck Rich (Bank 1 Sensor 2)Normal riskP2279Intake Air System LeakNormal riskP242FDiesel Particulate Filter Restriction – Ash AccumulationHigh riskP2452Diesel Particulate Filter "A" Pressure Sensor CircuitNormal riskP2453Diesel Particulate Filter "A" Pressure Sensor Circuit Range/PerformanceNormal riskP2454Diesel Particulate Filter "A" Pressure Sensor Circuit LowNormal riskP2455Diesel Particulate Filter "A" Pressure Sensor Circuit HighNormal riskP2458Diesel Particulate Filter Regeneration DurationHigh riskP2463Diesel Particulate Filter Restriction – Soot Accumulation (Bank 1)High riskP250FEngine Oil Level Too LowHigh riskU0001High Speed CAN Communication BusHigh riskU0002High Speed CAN Communication Bus PerformanceHigh riskU0003High Speed CAN Communication Bus (+) OpenHigh riskU0028Vehicle Communication Bus AHigh riskU0029Vehicle Communication Bus A PerformanceHigh riskU0073Control Module Communication Bus "A" OffHigh riskU0074Control Module Communication Bus "B" OffHigh riskU0100Lost Communication With ECM/PCM "A"High riskU0101Lost Communication With TCMHigh riskU0102Lost Communication With Transfer Case Control ModuleHigh riskU0103Lost Communication With Gear Shift Control Module "A"High riskU0104Lost Communication With Cruise Control ModuleHigh riskU0106Lost Communication With Glow Plug Control Module 1High riskU0107Lost Communication With Throttle Actuator "A" Control ModuleHigh riskU0109Lost Communication With Fuel Pump Control Module "A"High riskU0110Lost Communication With Drive Motor Control Module "A"High riskU0111Lost Communication With Battery Energy Control Module "A"High riskU0114Lost Communication With Four-Wheel Drive Clutch Control ModuleHigh riskU0115Lost Communication With ECM/PCM "B"High riskU0121Lost Communication With Anti-Lock Brake System (ABS) Control ModuleHigh riskU0122Lost Communication With Vehicle Dynamics Control ModuleHigh riskU0123Lost Communication With Yaw Rate Sensor ModuleHigh riskU0124Lost Communication With Lateral Acceleration Sensor ModuleHigh riskU0125Lost Communication With Multi-axis Acceleration Sensor Module "A"High riskU0126Lost Communication With Steering Angle Sensor ModuleHigh riskU0127Lost Communication With Tire Pressure Monitor ModuleHigh riskU0128Lost Communication With Park Brake Control ModuleHigh riskU0129Lost Communication With Brake System Control ModuleHigh riskU0130Lost Communication With Steering Effort Control ModuleHigh riskU0131Lost Communication With Power Steering Control ModuleHigh riskU0132Lost Communication With Suspension Control Module "A"High riskU0140Lost Communication With Body Control ModuleNormal riskU0141Lost Communication With Body Control Module "A"Normal riskU0142Lost Communication With Body Control Module "B"Normal riskU0146Lost Communication With Gateway "A"Normal riskU0147Lost Communication With Serial Data Gateway Module "B"Normal riskU0151Lost Communication With Restraints Control ModuleHigh riskU0155Lost Communication With Instrument Panel Cluster (IPC) Control ModuleNormal riskU0156Lost Communication With Information Center "A"Normal risk