Scan Tool Does Not Power Up

SCAN TOOL DOES NOT POWER UP

CIRCUIT DESCRIPTION
The data link connector (DLC) provides operating power for the scan tool at terminal 16 (battery positive voltage) and at terminal 4 (battery negative voltage).

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. Many modules, however, may not communicate unless the ignition is on.

TEST DESCRIPTION

Step 1:

Steps 2 - 4:

The numbers below refer to the step numbers on the diagnostic table.
1. The IPC/HVAC BATT fuse supplies power to terminal 16 of the DLC.
4. The battery positive voltage and ground circuits of the DLC are functioning properly. The malfunction must be due to the scan tool.