scantool

A scantool, also known as an OBD-II scanner or diagnostic tool, is an electronic device used to access and interpret data from a vehicle's onboard computer system. This system, governed by the On-Board Diagnostics II (OBD-II) standard, monitors various engine and emission control components. When a problem is detected, the vehicle's computer stores a Diagnostic Trouble Code (DTC) and typically illuminates the "check engine" light on the dashboard.

A scantool connects to the vehicle's OBD-II port, usually located under the dashboard. Once connected, it can retrieve these stored DTCs, providing a code that corresponds to a specific issue. Many scantools can also display real-time data from the vehicle's sensors, such as engine RPM, coolant temperature, and fuel pressure. This live data can be invaluable for diagnosing intermittent problems or understanding the vehicle's performance.

The information provided by a scantool allows vehicle owners and technicians to identify potential malfunctions and their severity. This can range from simple issues like a loose gas cap to more complex engine or transmission problems. While basic scantools retrieve DTCs and live data, advanced professional-grade tools can also perform functions like clearing DTCs, resetting service lights, and even programming vehicle modules. The use of scantools has significantly simplified vehicle diagnostics, making repairs more efficient and accessible.