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
U0001High 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 riskU0158Lost Communication With Head Up DisplayNormal riskU0159Lost Communication With Parking Assist Control Module "A"Normal riskU0160Lost Communication With Audible Alert Control ModuleNormal riskU0163Lost Communication With Navigation Control ModuleNormal riskU0164Lost Communication With HVAC Control ModuleNormal riskU0167Lost Communication With Vehicle Immobilizer Control ModuleHigh riskU0168Lost Communication With Vehicle Security Control ModuleHigh riskU0181Lost Communication With Headlamp Leveling Control Module "A"Normal riskU0182Lost Communication With Lighting Control Module - FrontNormal riskU0184Lost Communication With RadioNormal riskU0197Lost Communication With Telephone Control ModuleNormal riskU0198Lost Communication With Telematic Control ModuleNormal riskU0199Lost Communication With Door Control Module "A"Normal riskU0200Lost Communication With Door Control Module "B"Normal riskU0208Lost Communication With Seat Control Module "A"Normal riskU0212Lost Communication With Steering Column Control ModuleNormal riskU0214Lost Communication With Remote Function Actuation ModuleNormal riskU0235Lost Communication With Cruise Control Front Distance Range SensorHigh riskU0293Lost Communication With Hybrid/EV Powertrain Control ModuleHigh riskU0300Internal Control Module Software IncompatibilityNormal riskU0301Software Incompatibility With ECM/PCMNormal riskU0302Software Incompatibility With Transmission Control ModuleNormal riskU0401Invalid Data Received From ECM/PCM "A"Normal riskU0402Invalid Data Received From Transmission Control ModuleNormal riskU0415Invalid Data Received From Anti-Lock Brake System (ABS) Control ModuleNormal riskU0416Invalid Data Received From Vehicle Dynamics Control ModuleNormal riskU0418Invalid Data Received From Brake System Control Module "A"Normal riskU0420Invalid Data Received From Power Steering Control Module "A"Normal riskU0422Invalid Data Received From Body Control ModuleNormal riskU0423Invalid Data Received From Instrument Panel Cluster Control ModuleNormal riskU0428Invalid Data Received From Steering Angle Sensor ModuleNormal risk