onboard diagnostics scanner

An **onboard diagnostics (OBD) scanner** is an electronic device used to communicate with a vehicle’s onboard computer system to retrieve diagnostic information. It connects to the vehicle’s OBD port (typically located under the dashboard) and reads diagnostic trouble codes (DTCs) related to engine performance, emissions, and other vehicle systems.

OBD scanners can:
- Read and clear error codes
- Display real-time sensor data
- Monitor emissions system status
- Help diagnose engine and system problems

They are commonly used by mechanics and vehicle owners to identify and troubleshoot automotive issues.