Several websites sell automotive diagnostic tools, including EASE Diagnostics, CNAutoTool, Auto in the Box, and Northern Tool + Equipment. Automotive diagnostic tools read a vehicle's onboard computer to discover problems with the vehicle when a warning light activates.
Diagnostic tools include handheld devices, computer programs and electronic system gauges to evaluate diagnostic trouble codes, emission levels and software alerts for domestic, Asian and European vehicles. Diagnostic devices connect to the vehicle's access point for the computer and electrical system.
Prices range from $50 to more than $1,000 depending on the type of diagnostic device. Professional mechanics use similar tools to determine what needs to be fixed on a vehicle.