A car repair resource site that helps you diagnose vehicle OBD, OBD-II, and OBD2 problems. We have many articles on how to diagnose and repair many check engine light codes.

OBD-II (Check Engine Light) Trouble Codes Welcome to OBD-Codes.com, your headquarters for everything OBD-II related. For more information on what OBD codes are, OBD-II codes …

Get definitions and auto repair information for thousands of OBD-II codes. Look up B, C, U and P codes to diagnose your car problem.

How to read the codes 1. Ground terminals A and B (see diagram below) with the ignition "ON" and engine not running. The system will enter the diagnostic mode. In this mode, the computer …

Information on diagnosing and repairing a vehicle DTC trouble code P0446 which is EVAP emission control system incorrect purge flow.

Engine codes P0135 (HO2S Performance Bank 1 Sensor 1) and P0030 (HO2S Heater circuit Bank 1 Sensor 1). I replaced the upstream oxygen sensor (bank 1 sensor 1) with an NGK …

Codes vs Onboard message; Onboard Messages: Reduced engine power, Service Traction control, I get no codes Codes: P0223 Throttle Position (TP) Sensor 2 Circuit High Voltage; …

Information on diagnosing and repairing a DTC trouble code P0401 which is insufficient EGR (exhaust gas recirculation) flow.

Information on methods to reset the check engine light or OBD-II codes.

P0305 Cylinder #5 Misfire Technical Description Cylinder #5 Misfire Detected What does that mean? This diagnostic trouble code (DTC) is a generic powertrain code, which means that it …