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.
- P0169Generic · PowertrainIncorrect Fuel Composition
- P016AGeneric · PowertrainExcessive Time To Enter Closed Loop Air/Fuel Ratio Control
- P016BGeneric · PowertrainClosed Loop Air/Fuel Ratio Control At Limit - System Too Rich
- P016CGeneric · PowertrainClosed Loop Air/Fuel Ratio Control At Limit - System Too Lean
- P016DGeneric · PowertrainExcessive Time To Enter Closed Loop Fuel Pressure Control
- P016EGeneric · PowertrainClosed Loop Fuel Pressure Control At Limit - Pressure Too High
- P016FGeneric · PowertrainClosed Loop Fuel Pressure Control At Limit - Pressure Too Low
- P0170Generic · PowertrainFuel Trim Bank 1
- P0171Generic · PowertrainSystem Too Lean Bank 1
- P0172Generic · PowertrainSystem Too Rich Bank 1
- P0173Generic · PowertrainFuel Trim Bank 2
- P0174Generic · PowertrainSystem Too Lean Bank 2
- P0175Generic · PowertrainSystem Too Rich Bank 2
- P0176Generic · PowertrainFuel Composition Sensor Circuit
- P0177Generic · PowertrainFuel Composition Sensor Circuit Range/Performance
- P0178Generic · PowertrainFuel Composition Sensor Circuit Low
- P0179Generic · PowertrainFuel Composition Sensor Circuit High
- P017AGeneric · PowertrainCylinder Head Temperature Sensor A Circuit
- P017BGeneric · PowertrainCylinder Head Temperature Sensor A Range/Performance
- P017CGeneric · PowertrainCylinder Head Temperature Sensor A Circuit Low
- P017DGeneric · PowertrainCylinder Head Temperature Sensor A Circuit High
- P017EGeneric · PowertrainCylinder Head Temperature Sensor A Circuit Intermittent/Erratic
- P017FGeneric · PowertrainEVAP System Leak Detection Pump Module Air Filter Restricted
- P0180Generic · PowertrainFuel Temperature Sensor A Circuit
- P0181Generic · PowertrainFuel Temperature Sensor A Circuit Range/Performance
- P0182Generic · PowertrainFuel Temperature Sensor A Circuit Low
- P0183Generic · PowertrainFuel Temperature Sensor A Circuit High
- P0184Generic · PowertrainFuel Temperature Sensor A Circuit Intermittent
- P0185Generic · PowertrainFuel Temperature Sensor B Circuit
- P0186Generic · PowertrainFuel Temperature Sensor B Circuit Range/Performance
