Scan Tool Does Not Power Up. Buick GL7 (Export) 2000

For 1990-2009 cars

### Circuit Description

The data link connector (DLC) provides operating power for the scan tool at terminal 16 (battery positive voltage) and at terminal 4 (ground). The DLC provides the class 2 serial data signal at terminal 2 and signal ground at terminal 5. The scan tool will power up with the ignition off.

### Test Description

1. The CIGAR/DLC 15A fuse supplies power to the DLC terminal 16.

2. The DLC battery positive voltage and ground circuits are functioning properly. The malfunction must be due to the scan tool.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Test the DLC battery positive voltage circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 2
2 | Test the DLC ground circuit terminal 4 for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 3
3 | Inspect for poor connections/terminal tension at the DLC terminals 4 and 16. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | Go to Control Module References for the applicable Diagnostic System Check | Go to Step 4
4 | The scan tool may be malfunctioning. Refer to the scan tool instruction manual. Did you obtain a properly operating scan tool? | Go to Control Module References for the applicable Diagnostic System Check | --