An OBD diagnostic scan connects to the car's onboard computer to read stored fault codes, revealing engine, transmission and electronic problems that may not be obvious during a test drive.
Modern cars constantly monitor themselves through the onboard diagnostics (OBD) system. When a sensor or component behaves abnormally, the computer stores a fault code. An OBD scanner plugs into the car's diagnostic port and reads these codes, giving the inspector a window into problems you cannot always see or hear.
A scan can flag issues with the engine, transmission, ABS, airbags, emissions and many electronic modules. Some codes point to active faults you will feel on the road, while others are stored history that shows a problem happened before, even if a warning light has been cleared.
This is important because sellers sometimes reset the dashboard warning lights before a viewing. A car can look perfect with no lights showing, yet still hold stored codes that tell a different story. The scan helps cut through that and reveal what the car's own computer knows.
In an INSPECTMOTORS inspection the scan results are read alongside the physical checks and test drive. A code on its own does not always mean a costly repair, so our inspectors interpret what each code likely means for that specific car and how urgent it is.
Related: Engine Oil Leaks | EV Battery Health Check | Pre-Purchase Inspection (PPI) | Suspension & Steering Check