The data link connector (DLC) provides operating power for the scan tool at terminal 16 (Sirius - battery positive voltage) and terminal G (Fenix battery positive voltage). The ground for the scan tool is provided at terminal 4 (Sirius ground DLC) and terminal A (Fenix ground DLC). The 16 pin DLC for the Sirius application provides the serial data signals at terminals 7 (ECM serial data), 8 (Theft Deterrent serial data), 9 (ABS serial data), and 13 (SIR serial data). The 12 pin DLC for the Fenix provides the serial data signals at terminals C (ECM serial data), H (Theft Deterrent serial data), J (SIR serial data), and M (ABS serial data). The scan tool will power up with the ignition off. The ignition must be ON order for the scan tool to communicate with a control module.
The numbers below refer to the step numbers on the diagnostic table.
Fuse F11 supplies power to terminal 16 (Sirius) or terminal G (Fenix) of the DLC.
The battery positive voltage and ground circuits of the DLC are functioning properly. The malfunction must be due to the scan tool.
Step  | Action  | Yes  | No  | 
|---|---|---|---|
Test the battery positive voltage circuit of the DLC for an open or short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?  | Go to Step 5  | Go to Step 2  | |
2  | Test the ground circuit of the DLC for an open. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?  | Go to Step 5  | Go to Step 3  | 
3  | Inspect for poor connections at the DLC ground terminals and the DLC power terminals at the DLC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?  | Go to Step 5  | Go to Step 4  | 
The scan tool may be malfunctioning. Refer to the scan tool user guide. Did you obtain a properly operating scan tool?  | Go to Step 5  | --  | |
5  | Does the scan tool power up?  | Go to Step 1  |