The scan tool displays module data. This information assists in determining whether the module is operating properly and whether the module is sending or receiving the proper data to and from a particular system. The module uses data received from other systems in order to carry out some functions. Therefore, if the module receives incorrect data from another system, the module may seem to be functioning improperly. Use the scan tool in order to review the data received from the systems that interact with the module to aid in the diagnostic process.

The scan tool also displays the modules input/output status. By selecting the modules input/output status display, the scan tool determines if the switched inputs/outputs are being properly interpreted. The display also indicates if the input/output has changed states. For example, when a door is closed, the scan tool displays the input status of the door ajar switch as INACTIVE. When the door is open, the scan tool reads ACTIVE. Use this type of information in order to diagnose a malfunction associated with a particular system input or an input that is shared with another system.

Use the scan tool in order to control some of the module controlled outputs on and off. Use this feature in order to determine if the module can control an output regardless of the inputs to the module or any specific program instructions. Once a test is selected, the scan tool can command the module to control an output. The scan tool then displays the status of the selected output. Ensure that the module actually performs each of the selected output functions, because the displayed status information represents only what the commands to the module and not what actually occurred.