Scan tools provide five major benefits for technicians: ac Scan tools are the easiest way to retrieve DTCa#39;s. ... Reading the DTC number off the scan tool screen is far more convenient. ... Ford, etc. with a single tool. Figure 2-44. Throttle closed, vacuum port covered. On systems that allow it, scan tools can also send commands to the computer. ... The technician retrieves an O2S code, such as the On-Board Diagnostics Generation II (OBD-II) P0130, and immediately replaces the sensor.