When your check engine light has turned on, or your car is showing other warning signs such as a low tire pressure sensor light or an exhaust leak, you’ll want to be sure that you can find the source of the problem quickly. This is where automotive diagnostic tools can come in handy. These devices can connect to your vehicle’s On-Board Diagnostic (OBD) system to scan for fault codes. The fault code is a short-hand description of the problem, and can help you figure out what needs to be fixed.
Most modern vehicles have an OBD system that monitors performance through a network of sensors. The system will store data when there’s an issue, and this information is logged as a fault in the computer system. This information can be retrieved using a device like a car code reader, or a scan tool that’s much more in-depth with its diagnoses.
A basic car code reader simply plugs into the OBD port and displays SAE-standard diagnostic trouble codes (DTCs), typically a list of alphanumeric codes that can be generated by any number of different malfunctions in a car. These devices often don’t support advanced manufacturer-proprietary test modes and don’t offer real-time monitoring of sensors.
A car scan tool or OBD2 scanner will be more in-depth than a basic code reader, and can be used to display live vehicle data and clear DTCs as well as read freeze-frame data and perform emissions tests. They also typically have a more user-friendly interface and are better equipped to deal with specific car models.