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.
- U0001Generic · NetworkHigh Speed CAN Communication Bus
- U0002Generic · NetworkHigh Speed CAN Communication Bus Performance
- U0003Generic · NetworkHigh Speed CAN Communication Bus (+) Open
- U0004Generic · NetworkHigh Speed CAN Communication Bus (+) Low
- U0005Generic · NetworkHigh Speed CAN Communication Bus (+) High
- U0006Generic · NetworkHigh Speed CAN Communication Bus (-) Open
- U0007Generic · NetworkHigh Speed CAN Communication Bus (-) Low
- U0008Generic · NetworkHigh Speed CAN Communication Bus (-) High
- U0009Generic · NetworkHigh Speed CAN Communication Bus (-) shorted to Bus (+)
- U0010Generic · NetworkMedium Speed CAN Communication Bus
- U0011Generic · NetworkMedium Speed CAN Communication Bus Performance
- U0012Generic · NetworkMedium Speed CAN Communication Bus (+) Open
- U0013Generic · NetworkMedium Speed CAN Communication Bus (+) Low
- U0014Generic · NetworkMedium Speed CAN Communication Bus (+) High
- U0015Generic · NetworkMedium Speed CAN Communication Bus (-) Open
- U0016Generic · NetworkMedium Speed CAN Communication Bus (-) Low
- U0017Generic · NetworkMedium Speed CAN Communication Bus (-) High
- U0018Generic · NetworkMedium Speed CAN Communication Bus (-) shorted to Bus (+)
- U0019Generic · NetworkLow Speed CAN Communication Bus
- U0020Generic · NetworkLow Speed CAN Communication Bus Performance
- U0021Generic · NetworkLow Speed CAN Communication Bus (+) Open
- U0022Generic · NetworkLow Speed CAN Communication Bus (+) Low
- U0023Generic · NetworkLow Speed CAN Communication Bus (+) High
- U0024Generic · NetworkLow Speed CAN Communication Bus (-) Open
- U0025Generic · NetworkLow Speed CAN Communication Bus (-) Low
- U0026Generic · NetworkLow Speed CAN Communication Bus (-) High
- U0027Generic · NetworkLow Speed CAN Communication Bus (-) shorted to Bus (+)
- U0028Generic · NetworkVehicle Communication Bus A
- U0029Generic · NetworkVehicle Communication Bus A Performance
- U0030Generic · NetworkVehicle Communication Bus A (+) Open
