DTC codes
Look up an OBD-II fault code: what it means on every car or on your make, and how to track it down.
How to read a code
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 4
- AreaAuxiliary emission controls
- 20
- FaultThe specific fault in that area
Read the code
Note every stored and pending code your scanner shows, such as P0420.
Find it
Search by code or by words. For a manufacturer code (P1, B1, C1, U1) pick your make: its meaning differs by make.
Open the code
Its page explains the symptoms, likely causes, the checks to run and the fixes.
- P0302Generic · PowertrainCylinder 2 Misfire Detected
- P0302Audi · PowertrainWorn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems)
- P0303Generic · PowertrainCylinder 3 Misfire Detected
- P0303Audi · PowertrainWorn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems)
- P0304Generic · PowertrainCylinder 4 Misfire Detected
- P0304Audi · PowertrainWorn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problems)
- P0305Generic · PowertrainCylinder 5 Misfire Detected
- P0306Generic · PowertrainCylinder 6 Misfire Detected
- P0307Generic · PowertrainCylinder 7 Misfire Detected
- P0308Generic · PowertrainCylinder 8 Misfire Detected
- P0309Generic · PowertrainCylinder 9 Misfire Detected
- P030AGeneric · PowertrainIgnition A Control Signal Circuit/Open
- P030BGeneric · PowertrainIgnition A Control Signal Circuit Low
- P030CGeneric · PowertrainIgnition A Control Signal Circuit High
- P030DGeneric · PowertrainIgnition B Control Signal Circuit/Open
- P030EGeneric · PowertrainIgnition B Control Signal Circuit Low
- P030FGeneric · PowertrainIgnition B Control Signal Circuit High
- P0310Generic · PowertrainCylinder 10 Misfire Detected
- P0311Generic · PowertrainCylinder 11 Misfire Detected
- P0312Generic · PowertrainCylinder 12 Misfire Detected
- P0313Generic · PowertrainMisfire Detected With Low Fuel
- P0314Generic · PowertrainSingle Cylinder Misfire (Cylinder not Specified)
- P0315Generic · PowertrainCrankshaft Position System Variation Not Learned
- P0316Generic · PowertrainEngine Misfire Detected on Startup (First 1000 Revolutions)
- P0317Generic · PowertrainRough Road Hardware Not Present
- P0318Generic · PowertrainRough Road Sensor A Signal Circuit
- P0319Generic · PowertrainRough Road Sensor B Signal Circuit
- P031AGeneric · PowertrainIgnition C Control Signal Circuit/Open
- P031BGeneric · PowertrainIgnition C Control Signal Circuit Low
- P031CGeneric · PowertrainIgnition C Control Signal Circuit High
