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.
- P2437Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Low Bank 2
- P2438Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit High Bank 2
- P2439Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 2
- P243AGeneric · PowertrainParticulate Filter Restriction - Ash Accumulation Bank 2
- P243BGeneric · PowertrainParticulate Filter Restriction - Forced Limited Power Bank 2
- P243CGeneric · PowertrainParticulate Filter Regeneration Frequency Bank 2
- P243DGeneric · PowertrainParticulate Filter Regeneration Duration Bank 2
- P243EGeneric · PowertrainParticulate Filter Regeneration Incomplete Bank 2
- P243FGeneric · PowertrainParticulate Filter Restriction - Soot Accumulation Too High Bank 2
- P2440Generic · PowertrainAIR System Switching Valve Stuck Open Bank 1
- P2441Generic · PowertrainAIR System Switching Valve Stuck Closed Bank 1
- P2442Generic · PowertrainAIR System Switching Valve Stuck Open Bank 2
- P2443Generic · PowertrainAIR System Switching Valve Stuck Closed Bank 2
- P2444Generic · PowertrainAIR System Pump Stuck On Bank 1
- P2445Generic · PowertrainAIR System Pump Stuck Off Bank 1
- P2446Generic · PowertrainAIR System Pump Stuck On Bank 2
- P2447Generic · PowertrainAIR System Pump Stuck Off Bank 2
- P2448Generic · PowertrainAIR System High Air Flow Bank 1
- P2449Generic · PowertrainAIR System High Air Flow Bank 2
- P244AGeneric · PowertrainParticulate Filter Differential Pressure Too Low Bank 1
- P244BGeneric · PowertrainParticulate Filter Differential Pressure Too High Bank 1
- P244CGeneric · PowertrainExhaust Temperature Too Low For Particulate Filter Regeneration Bank 1
- P244DGeneric · PowertrainExhaust Temperature Too High For Particulate Filter Regeneration Bank 1
- P244EGeneric · PowertrainExhaust Temperature Too Low For Particulate Filter Regeneration Bank 2
- P244FGeneric · PowertrainExhaust Temperature Too High For Particulate Filter Regeneration Bank 2
- P2450Generic · PowertrainEVAP System Switching Valve Performance/Stuck Open
- P2451Generic · PowertrainEVAP System Switching Valve Stuck Closed
- P2452Generic · PowertrainParticulate Filter Pressure Sensor A Circuit
- P2453Generic · PowertrainParticulate Filter Pressure Sensor A Circuit Range/Performance
- P2454Generic · PowertrainParticulate Filter Pressure Sensor A Circuit Low
