What does "checking for codes" in an OBD-II system typically involve?

Checking for codes in an OBD-II system involves using a scan tool to retrieve diagnostic trouble codes (DTCs). These codes are generated by the vehicle’s onboard computer when it detects a fault in one of the systems monitored by the OBD-II. When a particular component is not functioning as intended, the system logs a DTC which can then be accessed with a scan tool.

This process is essential for diagnosing issues because the codes provide specific information about the nature of the problem, making it easier for technicians to pinpoint the source of a malfunction. Additionally, the scan tool can display other valuable information, such as freeze frame data and live data from various sensors, aiding the technician in making informed decisions about repairs.

While physically inspecting the engine, resetting the system, or replacing the vehicle's battery may be part of the overall service process, they are not specifically related to the act of checking for codes in the OBD-II system itself. Only retrieving diagnostic trouble codes with a scan tool directly addresses the question's focus on what "checking for codes" entails.