Turn your smartphone into a professional car diagnostic tool with a $15-30 OBD2 adapter and free apps that read engine codes in seconds.

We may receive a commission on purchases made from links. Electrical diagnostic work is one of the most challenging parts of automotive repair. It can be incredibly daunting for beginners or DIY ...

The top end of the technology ladder is held by a scan tool. This car diagnostic tool plugs into the OBD-II port (“OBD” is an acronym for on-board diagnostics, and the “II” designates the second ...