OBD-II code lookup
Enter a code like P0300, search a keyword (misfire, lean, sensor…), or browse by family. Every result explains the meaning, likely causes, symptoms and the checks a mechanic would run.
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Code families
P0xxx
Engine, fuel, ignition and emissions — the most common faults.
171 codes · browse →C0xxx
ABS, traction control and stability electronics.
15 codes · browse →B0xxx
Airbags (SRS), climate control, lights and body modules.
6 codes · browse →U0xxx
Communication faults between modules over the CAN bus.
16 codes · browse →Most searched codes
Systems covered
What is OBD-II?
On-Board Diagnostics II is the standardized system every car since 1996 uses to report faults. The engine computer (ECM) watches hundreds of sensors and stores a trouble code when something is wrong. A scanner plugged into the OBD port reads those codes.
How to read a code
Every code has four characters. The first letter tells you the system:
- P — Powertrain (engine, fuel, emissions)
- C — Chassis (ABS, brakes, stability)
- B — Body (airbags, climate, lights)
- U — Network (module communication)
Where is the OBD port?
Usually under the dashboard, driver’s side — near the steering column, fuse box or hood release. On most cars it is a grey/black trapezoid with 16 pins. Use the free OBD live scanner with a BLE adapter, or any cheap reader.