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.
- P240AGeneric · PowertrainEVAP System Leak Detection Pump Heater Control Circuit/Open
- P240BGeneric · PowertrainEVAP System Leak Detection Pump Heater Control Circuit Low
- P240CGeneric · PowertrainEVAP System Leak Detection Pump Heater Control Circuit High
- P240DGeneric · PowertrainAlternative Fuel Low Pressure System Leak
- P240EGeneric · PowertrainAlternative Fuel High Pressure System Leak
- P240FGeneric · PowertrainEGR Slow Response
- P2410Generic · PowertrainFuel Cap Sensor/Switch Circuit Low
- P2411Generic · PowertrainFuel Cap Sensor/Switch Circuit High
- P2412Generic · PowertrainFuel Cap Sensor/Switch Circuit Intermittent/Erratic
- P2413Generic · PowertrainEGR System Performance
- P2414Generic · PowertrainO2 Sensor Exhaust Sample Error Bank 1 Sensor 1
- P2415Generic · PowertrainO2 Sensor Exhaust Sample Error Bank 2 Sensor 1
- P2416Generic · PowertrainO2 Sensor Signals Swapped Bank 1 Sensor 2/Bank 1 Sensor 3
- P2417Generic · PowertrainO2 Sensor Signals Swapped Bank 2 Sensor 2/Bank 2 Sensor 3
- P2418Generic · PowertrainEVAP System Switching Valve Control Circuit/Open
- P2419Generic · PowertrainEVAP System Switching Valve Control Circuit Low
- P241AGeneric · PowertrainO2 Sensor Signals Swapped Bank 1 Sensor 1/Bank 1 Sensor 2
- P241BGeneric · PowertrainO2 Sensor Signals Swapped Bank 2 Sensor 1/Bank 2 Sensor 2
- P241CGeneric · PowertrainThrottle Actuator Control System - Ice Blockage Bank 2
- P241DGeneric · PowertrainSCR Inducement - Forced Engine Shutdown
- P241EGeneric · PowertrainReductant Heater Coolant Control Valve Stuck Closed
- P241FGeneric · PowertrainEGR Cooler B Efficiency Below Threshold
- P2420Generic · PowertrainEVAP System Switching Valve Control Circuit High
- P2421Generic · PowertrainEVAP System Vent Valve Stuck Open
- P2422Generic · PowertrainEVAP System Vent Valve Stuck Closed
- P2423Generic · PowertrainHC Adsorption Catalyst Efficiency Below Threshold Bank 1
- P2424Generic · PowertrainHC Adsorption Catalyst Efficiency Below Threshold Bank 2
- P2425Generic · PowertrainEGR Cooling Valve Control Circuit/Open
- P2426Generic · PowertrainEGR Cooling Valve Control Circuit Low
- P2427Generic · PowertrainEGR Cooling Valve Control Circuit High
