Test A: Scan Tool Does Not Power Up: Description
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2002 GMC Savana, 2002 Chevrolet Chevy Express, 2001 GMC Savana Special, 2001 GMC Savana Camper Special, and 2001 GMC Savana. However, it is still accessible from the selected car via links, so may be relevant.
The Data Link Connector (DLC) provides battery positive voltage for the scan tool at terminal 16 and ground at terminal 4. DLC provides class 2 signal at terminal 2 and signal ground at terminal 5. Scan tool will power up with the ignition OFF.