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.
- P1421Subaru · PowertrainExhaust Gas Recirculation Circuit High Input
- P1421Volkswagen · PowertrainSecondary Air Injection Valve Circuit Short To Ground
- P1422BMW · PowertrainSecondary Air System Bank 2
- P1422Other · PowertrainEGI Temperature Sensor Failure
- P1422Subaru · PowertrainEVAP Purge Control Solenoid Valve Circuit High Input
- P1422Volkswagen · PowertrainSecondary Air Injection Valve Circuit Short To B+
- P1423Buick · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Cadillac · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Chevrolet · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Chrysler · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423GM · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423GMC · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Oldsmobile · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Other · PowertrainEGI Functionality Test Failed
- P1423Plymouth · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Pontiac · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Saturn · PowertrainIntake Air High Pressure Switch Circuit High Voltage
- P1423Subaru · PowertrainEVAP Vent Control High Input
- P1423Volkswagen · PowertrainSecondary Air Injection System Bank 1 Flow Too Low
- P1424Other · PowertrainEGI Glow Plug Primary Failure
- P1424Volkswagen · PowertrainSecondary Air Injection System Bank 1 Leak Detected
- P1425Kia · PowertrainEVAP Purge Control Solenoid Circuit Low Voltage
- P1425Other · PowertrainEGI Glow Plug Secondary Failure
- P1425Volkswagen · PowertrainTank Ventilation Valve Short To Ground
- P1426Other · PowertrainEGI Mini - MAF Failed Out Of Range
- P1426Volkswagen · PowertrainTank Ventilation Valve Open Circuit
- P1427Other · PowertrainEGI Mini - MAF Failed Short Circuit
- P1428Other · PowertrainEGI Mini - MAF Failed Open Circuit
- P1429Other · PowertrainElectric Air Pump Primary Failure
- P1430Other · PowertrainElectric Air Pump Secondary Failure
