For 1990-2009 cars

### Data Display

The Scan Tool displays the 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 the incorrect data from another system, the module may function improperly. Use the Scan Tool to review the data from the systems that interact with the module.

### Displayed Input/Output Status

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 has changed states. For example, when a door is closed, theScan 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 when diagnosing a malfunction associated with a particular module input or an input that is shared with another system.

### Control Outputs

Use a Scan Tool to control the module output functions. When the module output control is selected, the Scan Tool can command the module to turn an output on or off. This feature can be used to determine if the module is able to control an output regardless of the inputs or any specific program instructions. Once a test is selected, the Scan Tool will command the module to energize the selected output. The Scan Tool then displays the status of the selected output. The displayed information represents only what was module commanded, not what action was actually taken. Check if the module is actually performing each of the selected output functions. It may be necessary to have the ignition in the RUN position to control outputs.