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.
- 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
- P2422Audi · PowertrainEVAP vent valve failure, Powertrain Control Module (PCM) failure, Wiring issue
- 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
- P2428Generic · PowertrainExhaust Gas Temperature Too High Bank 1
- P2429Generic · PowertrainExhaust Gas Temperature Too High Bank 2
- P242AGeneric · PowertrainExhaust Gas Temperature Sensor Circuit Bank 1 Sensor 3
- P242BGeneric · PowertrainExhaust Gas Temperature Sensor Circuit Range/Performance Bank 1 Sensor 3
- P242CGeneric · PowertrainExhaust Gas Temperature Sensor Circuit Low Bank 1 Sensor 3
- P242DGeneric · PowertrainExhaust Gas Temperature Sensor Circuit High Bank 1 Sensor 3
- P242EGeneric · PowertrainExhaust Gas Temperature Sensor Circuit Intermittent/Erratic Bank 1 Sensor 3
- P242FGeneric · PowertrainParticulate Filter Restriction - Ash Accumulation Bank 1
- P2430Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Bank 1
- P2431Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Range/Performance Bank 1
- P2431Audi · PowertrainAir control solenoid failure, Powertrain Control Module (PCM) failure, Secondary Air System pressure sensor failure, Wiring issue
- P2432Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Low Bank 1
- P2432Audi · PowertrainAir control solenoid failure, Powertrain Control Module (PCM) failure, Secondary Air System pressure sensor failure, Wiring issue
- P2433Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit High Bank 1
- P2434Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Intermittent/Erratic Bank 1
- P2435Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Bank 2
- P2436Generic · PowertrainAIR System Air Flow/Pressure Sensor Circuit Range/Performance Bank 2
