Test A: Scan Tool Does Not Power Up: Description

The Data Link Connector (DLC) provides operating power for the scan tool at terminal No. 16 (battery positive voltage) and at terminal No. 4 (ground). The DLC provides the Class 2 serial data signals at terminal No. 7. The scan tool will power up with the ignition OFF. Many modules, however, will not communicate unless the DIM detects that the ignition is ON and sends the appropriate power mode message.