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.
- P24EBGeneric · PowertrainNH3 Sensor Supply Voltage Circuit Low
- P24ECGeneric · PowertrainNH3 Sensor Supply Voltage Circuit High
- P24EDGeneric · PowertrainNH3 Sensor Calibration Memory
- P24EEGeneric · PowertrainNH3 Sensor Processor Performance
- P24EFGeneric · PowertrainControl Module Wake-up Circuit/Open
- P24F0Generic · PowertrainControl Module Wake-up Circuit Low
- P24F1Generic · PowertrainControl Module Wake-up Circuit High
- P24F2Generic · PowertrainEGR Temperature/Charge Air Cooler Temperature Correlation
- P24F3Generic · PowertrainReductant Tank Temperature/Fuel Temperature Correlation
- P24F4Generic · PowertrainNOx Sensor Delayed Response - High to Low Bank 1 Sensor 1
- P24F5Generic · PowertrainNOx Sensor Delayed Response - High to Low Bank 1 Sensor 2
- P24F6Generic · PowertrainExhaust Aftertreatment Fuel Air Purge Valve Stuck Open
- P24F7Generic · PowertrainExhaust Aftertreatment Fuel Air Purge Valve Stuck Closed
- P24F8Generic · PowertrainExhaust Aftertreatment Fuel Air Purge Valve Control Circuit
- P24F9Generic · PowertrainExhaust Aftertreatment Fuel Air Purge Valve Control Circuit Range/Performance
- P24FAGeneric · PowertrainExhaust Aftertreatment Fuel Air Purge Valve Control Circuit Low
- P24FBGeneric · PowertrainExhaust Aftertreatment Fuel Air Purge Valve Control Circuit High
- P24FCGeneric · PowertrainParticulate Matter Sensor Heater Control Circuit Driver Current/Temperature Too High
- P24FDGeneric · PowertrainParticulate Filter A Incorrect
- P24FEGeneric · PowertrainSCR Catalyst Incorrect
- P24FFGeneric · PowertrainReductant Temperature Too High
- P2500Generic · PowertrainGenerator Lamp/L-Terminal Circuit Low
- P2500Audi · PowertrainAlternator failure, Battery failure, Powertrain Control Module (PCM) failure, Wiring issue
- P2501Generic · PowertrainGenerator Lamp/L-Terminal Circuit High
- P2501Audi · PowertrainAlternator failure, Battery failure, Powertrain Control Module (PCM) failure, Wiring issue
- P2502Generic · PowertrainCharging System Voltage
- P2503Generic · PowertrainCharging System Voltage Low
- P2503Audi · PowertrainAlternator failure, Battery failure, Wiring issue
- P2504Generic · PowertrainCharging System Voltage High
- P2505Generic · PowertrainECM/PCM Power Input Signal
