OBD-II Code Lookup
Decode OBD-II diagnostic trouble codes (DTCs) — Pxxxx, Bxxxx, Cxxxx, Uxxxx.
How to Use
- Enter a DTC (e.g. P0171).
- See the structure, family, and common meaning.
- Search the table for common codes.
Lookup
Info
Code Structure
1st char
P/B/C/U — system
2nd char
0 generic, 1 manuf.
3rd char
Sub-system (P0=fuel/air, P1=trans, etc.)
4th/5th
Specific fault
P0xxx
SAE generic powertrain
P1xxx
Manufacturer-specific
Frequently Asked Questions
What does the first letter mean?
P = powertrain, B = body, C = chassis, U = network.
Generic vs manufacturer?
Second digit 0 = generic (SAE), 1 = manufacturer-specific.
Common Use Cases
Check engine light
Translate a scan tool reading.
Second opinion
Verify a shop diagnosis before parts purchase.
Last updated: