Scan Tool Does Not Power Up

Scan Tool Does Not Power Up

CIRCUIT DESCRIPTION
The data link connector (DLC) is a standardized 16 cavity connector. Connector design and location is dictated by an industry wide standard, and is required to provide the following:
- Scan tool power battery positive voltage at terminal 16
- Scan tool power ground at terminal 4
- Common signal ground at terminal 5

The scan tool will power up with the ignition OFF. Some modules however, will not communicate unless the ignition is ON.

Scan Tool Does Not Power Up
Schematic Reference: Engine Controls Schematics
Connector End View Reference: Engine Controls Connector End Views