GM Service Manual Online
For 1990-2009 cars only

Data Link Connector (DLC)

The data link connector (DLC) contains the class 2 serial data links:

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

    • Unswitched voltage (B+) at DLC terminal 16 (circuit 540)
    • Ground at terminal 4 (circuit 650) and terminal 5 (circuit 451)

Class 2 Serial Data Link

The class 2 serial data link allows the following modules to communicate data with each other:

    • Electronic brake/traction control module (EBTCM)
    • Instrument panel cluster (IPC)
    • Powertrain control module (PCM)
    • Inflatable Restraint Sensing and Diagnostic Module (SDM).

The Class 2 serial data link allows a scan tool to communicate with the above modules for diagnostic and testing purposes. The Class 2 serial data link is located at the DLC connector terminal 2. Terminal 2 consists of the following circuits:

    • Circuit 1036
    • Circuit 1128
    • Circuit 1049
    • Circuit 1122
    • Circuit 1132