What does a scanner tool allow you to do when diagnosing electrical issues?

A scanner tool is an essential diagnostic instrument used in the automotive industry to troubleshoot electrical issues in vehicles. It enables technicians to read trouble codes generated by the vehicle’s onboard diagnostics (OBD) system, which is crucial for understanding what problems the vehicle is experiencing.

In addition to reading trouble codes, a scanner tool provides access to live data, allowing technicians to monitor various vehicle systems in real-time. This live data can include parameters such as engine RPM, coolant temperature, and sensor readings, all of which are vital for diagnosing issues effectively. Furthermore, the ability to monitor vehicle systems can aid in pinpointing intermittent problems that may not trigger a trouble code but still affect performance.

While resetting the vehicle's computer, checking battery voltage, and testing the alternator are important diagnostic tasks, they are more specialized and do not encompass the broader diagnostic capabilities provided by a scanner tool. Therefore, the correct answer highlights the comprehensive functionality of scanner tools in diagnosing electrical issues, making it invaluable for automotive technicians.