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. The ground for the scan tool is provided at terminal 4. The 16 pin DLC provides the serial data signals at terminal 7 ECM, TCM, terminal 3 speed sensitive power steering, terminal 12 EBCM, and terminal 13 SIR serial data. The scan tool will power up with the ignition OFF. The ignition must be ON in order for the scan tool to communicate with a control module.

Test Description

The numbers below refer to the step numbers on the diagnostic table.
1. Fuse F16 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.