Fault codes, also known as diagnostic trouble codes (DTCs), are stored in a car’s onboard computer when a sensor or system in the vehicle detects a problem. These codes can indicate issues with the engine, transmission, emissions, or other systems. To check for fault codes, a diagnostic scanner tool is required to be connected to the car’s onboard diagnostic (OBD) port, which is usually located under the dashboard on the driver’s side. Once connected, the scanner tool can read the codes and display them on the screen. Some advanced scanners can also provide additional information such as freeze frame data and live data.
Reading codes from vehicle control modules refers to the process of using a diagnostic tool to access the on-board computer systems in a vehicle and retrieve stored or active or current trouble codes. These codes can indicate issues with various systems and components, such as the engine, transmission, and emissions systems. By reading the codes, a mechanic or technician can quickly identify and diagnose problems with a vehicle, allowing for more efficient repairs.