Data Link Connector: Description and Operation

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.
^ Class 2 serial data at terminal 2.

The scan tool will power up with the ignition off. Some modules however, will not communicate unless the ignition is on and the power mode master (PMM) module sends the appropriate power mode message.