Which of the following can an aftermarket scan tool do?

• A. Read codes
• B. Clear codes
• C. Retrieve live data
• D. All of the Above

Answer: (D)

An aftermarket scan tool, when connected to the vehicle’s OBD-II port, can access the engine control unit to pull diagnostic trouble codes, clear those codes after repairs, and display live data from sensors in real time. Reading codes tells you what faults were detected. Clearing codes removes the stored codes and typically turns off the check engine light after the issue is addressed (though some monitors may need a drive cycle to reset). Retrieving live data lets you watch how sensors and systems are behaving as the engine runs, which is essential for diagnosing intermittent problems and confirming repairs. Because a versatile tool can perform all three tasks—read codes, clear codes, and retrieve live data—it fits all the listed capabilities. Some tools offer even more features, but these three basics cover the core diagnostic functions you’ll rely on.