GM Service Manual Online
For 1990-2009 cars only

The Data Link Connector (DLC) contains these serial data links:

    • Class 2
    • Entertainment and Comfort (E&C)

The DLC also provides a power source for the scan tool:

    • Unswitched voltage (B+) at DLC terminal 16 (circuit 640)
    • Ground at terminals 4 (circuit 1450) and 5 (circuit 1550)