The scan tool displays the module data. This information assists in determining whether the module operates properly and whether the module sends or receives 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 the incorrect data from another system, the module may function improperly. Use the scan tool in order to review the data from the systems that interact with the module.

The scan tool also displays the module input/output status. Select the module input/output status display in order to display the data and determine if the switched inputs/outputs can be properly interpreted. The display also indicates if the input/output changed states. For example, when a door closes, 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 kind of information in order to diagnose a malfunction associated with a particular module input or an input that is shared with another system.

Use a scan tool in order to control the module output functions. When the module output control is selected, the scan tool commands the module output on or off. Use this feature in order to determine if the module controls an output regardless of the inputs or any specific program instructions. Once a test is selected, the scan tool's command to the module energizes the selected output. The scan tool then displays the status of the selected output. The displayed information represents only what the module commanded, not what action actually occurred. Verify that the module actually performs each of the selected output functions. Turn the ignition to the RUN position in order to control outputs.