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.
- P1418Saturn · PowertrainSecondary Air Injection System Relay A Control Circuit High
- P1418Volkswagen · PowertrainFuel Level Sensor Signal Too High
- P1419Mazda · PowertrainSplit Air 2 Circuit
- P1419Other · PowertrainSplit Air #2 Circuit Malfunction
- P1420BMW · PowertrainSecondary Air Valve Control Circuit Electrical
- P1420Buick · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Cadillac · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Chevrolet · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Chrysler · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420GM · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420GMC · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Oldsmobile · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Other · PowertrainCatalyst Temperature Sensor Failure
- P1420Plymouth · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Pontiac · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Saturn · PowertrainIntake Air Low Pressure Switch Circuit Low Voltage
- P1420Subaru · PowertrainFuel Tank Pressure Control Solenoid High Input
- P1420Volkswagen · PowertrainSecondary Air Injection Control Module Electrical Malfunction
- P1421BMW · PowertrainSecondary Air System Bank 1
- P1421Buick · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421Cadillac · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421Chevrolet · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421Chrysler · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421GM · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421GMC · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421Oldsmobile · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421Other · PowertrainCatalyst Damage
- P1421Plymouth · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421Pontiac · PowertrainIntake Air Low Pressure Switch Circuit High Voltage
- P1421Saturn · PowertrainIntake Air Low Pressure Switch Circuit High Voltage