Find Fault Code
Search OBD-II diagnostic trouble codes by code, description, system family, severity, and repair category.
Important
A DTC identifies a circuit or system fault, not always the failed part. Manufacturer-specific codes can vary by brand, model and year. Confirm with the owner manual, service manual or OEM scan tool before replacing parts.
Popular OBD-II code guides
These static code pages are crawlable and can be opened directly from Google Search.
- P0300Random/Multiple Cylinder Misfire Detected
- P0171Fuel Trim too Lean (Bank 1)
- P0420Catalyst System Efficiency Below Threshold (Bank 1)
- P0455Evaporative Emission Control System Leak Detected (gross leak)
- P0128Coolant Thermostat Malfunction
- P0442Evaporative Emission Control System Leak Detected (small leak)
- P0135O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
- P0401Exhaust Gas Recirculation Flow Insufficient Detected
- P0011A Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
- P0014B Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
- P0101Mass or Volume Air Flow Circuit Range/Performance Problem
- P0113Intake Air Temperature Circuit High Input
- P0500Vehicle Speed Sensor Malfunction
- P0700Transmission Control System Malfunction
Quick answers
What is an OBD-II fault code?
An OBD-II fault code is a diagnostic trouble code stored by the vehicle when a system or circuit reports a problem.
Does a DTC always mean the part is faulty?
No. A DTC points to a system or circuit condition, so wiring, sensors, power, ground and related components should be checked before replacing parts.
Should I clear the code first?
Record the code and freeze-frame data before clearing it so the original fault condition is not lost.