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.
- P0478Generic · PowertrainExhaust Pressure Control Valve A High
- P0479Generic · PowertrainExhaust Pressure Control Valve A Intermittent
- P047AGeneric · PowertrainExhaust Pressure Sensor B Circuit
- P047BGeneric · PowertrainExhaust Pressure Sensor B Circuit Range/Performance
- P047CGeneric · PowertrainExhaust Pressure Sensor B Circuit Low
- P047DGeneric · PowertrainExhaust Pressure Sensor B Circuit High
- P047EGeneric · PowertrainExhaust Pressure Sensor B Circuit Intermittent/Erratic
- P047FGeneric · PowertrainExhaust Pressure Control Valve A Stuck Open
- P0480Generic · PowertrainFan 1 Control Circuit
- P0481Generic · PowertrainFan 2 Control Circuit
- P0482Generic · PowertrainFan 3 Control Circuit
- P0483Generic · PowertrainFan Rationality Check
- P0484Generic · PowertrainFan Circuit Current High
- P0485Generic · PowertrainFan Power/Ground Circuit
- P0486Generic · PowertrainEGR Sensor B Circuit
- P0487Generic · PowertrainEGR Throttle Control Circuit A /Open
- P0488Generic · PowertrainEGR Throttle Control Circuit A Range/Performance
- P0489Generic · PowertrainEGR A Control Circuit Low
- P048AGeneric · PowertrainExhaust Pressure Control Valve A Stuck Closed
- P048BGeneric · PowertrainExhaust Pressure Control Valve A Position Sensor/Switch Circuit
- P048CGeneric · PowertrainExhaust Pressure Control Valve A Position Sensor/Switch Circuit Range/Performance
- P048DGeneric · PowertrainExhaust Pressure Control Valve A Position Sensor/Switch Circuit Low
- P048EGeneric · PowertrainExhaust Pressure Control Valve A Position Sensor/Switch Circuit High
- P048FGeneric · PowertrainExhaust Pressure Control Valve A Position Sensor/Switch Circuit Intermittent/Erratic
- P0490Generic · PowertrainEGR A Control Circuit High
- P0491Generic · PowertrainAIR System Insufficient Flow Bank 1
- P0492Generic · PowertrainAIR System Insufficient Flow Bank 2
- P0493Generic · PowertrainFan Overspeed
- P0494Generic · PowertrainFan 1 Underspeed
- P0495Generic · PowertrainFan 1 Overspeed
