Automotive OBD (On-Board Diagnostics) repair involves using the car’s built-in computer system (OBD-II, standard since 1996) to self-diagnose issues, read fault codes (DTCs) via an OBD-II scanner, and pinpoint problems in emission, engine, and other systems for faster, more accurate fixes, saving time and money by identifying the source of the “Check Engine” light or performance issues.
How it works
Sensors & ECUs: Sensors monitor engine, transmission, and emissions components, sending data to the Engine Control Unit (ECU).
Fault Detection: When a problem arises (e.g., increased emissions), the ECU stores a Diagnostic Trouble Code (DTC) and illuminates the Check Engine Light.
Scanner Connection: A technician plugs an OBD-II scanner into the standardized port (usually under the dash).
Code Retrieval: The scanner reads the DTCs, revealing the specific system or component with the fault (e.g., a faulty oxygen sensor).
Diagnosis & Repair: Mechanics use these codes to quickly locate the issue, perform repairs (like replacing a sensor), and then use the scanner to clear the codes.