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.
- P259AGeneric · PowertrainTurbocharger Boost Control Position Sensor B Performance - Stuck Low
- P259BGeneric · PowertrainTurbocharger Boost Control Position Sensor B Performance - Stuck High
- P259CGeneric · PowertrainExcessive Time To Enter Closed Loop Turbocharger A Boost Control
- P259DGeneric · PowertrainExcessive Time To Enter Closed Loop Turbocharger B Boost Control
- P259EGeneric · PowertrainTurbocharger A Boost Control Position At Low Limit
- P259FGeneric · PowertrainTurbocharger A Boost Control Position At High Limit
- P25A0Generic · PowertrainTurbocharger B Boost Control Position At Low Limit
- P25A1Generic · PowertrainTurbocharger B Boost Control Position At High Limit
- P25A2Generic · PowertrainBrake System Control Module A Requested MIL Illumination
- P25A3Generic · PowertrainEngine Hood Open
- P25A4Generic · PowertrainFuel Mode Select Switch Circuit
- P25A5Generic · PowertrainFuel Mode Select Switch Performance
- P25A6Generic · PowertrainFuel Mode Select Switch Circuit Low
- P25A7Generic · PowertrainFuel Mode Select Switch Circuit High
- P25A8Generic · PowertrainFuel Mode Select Switch Circuit Intermittent/Erratic
- P25A9Generic · PowertrainPiston Cooling Oil Control Circuit/Open
- P25AAGeneric · PowertrainPiston Cooling Oil Control Circuit Low
- P25ABGeneric · PowertrainPiston Cooling Oil Control Circuit High
- P25ACGeneric · PowertrainPiston Cooling Oil Control Circuit Performance/Stuck Off
- P25ADGeneric · PowertrainPiston Cooling Oil Control Circuit Stuck On
- P25AEGeneric · PowertrainPiston Cooling Oil Pressure Too Low
- P25AFGeneric · PowertrainCoolant Temperature Control Module Requested MIL Illumination
- P25B0Generic · PowertrainFuel Level Sensor A Stuck
- P25B1Generic · PowertrainFuel Level Sensor B Stuck
- P25B2Generic · PowertrainFuel Level Sensor A or B Stuck
- P25B3Generic · PowertrainTurbocharger/Supercharger Wastegate A Stuck Open
- P25B4Generic · PowertrainTurbocharger/Supercharger Wastegate A Stuck Closed
- P25B5Generic · PowertrainTurbocharger/Supercharger Wastegate B Stuck Open
- P25B6Generic · PowertrainTurbocharger/Supercharger Wastegate B Stuck Closed
- P25B7Generic · PowertrainAuxiliary Ignition Switch On/Start Position Circuit
