GM Service Manual Online
For 1990-2009 cars only

Data Link Connector (DLC)

The data link connector (DLC) connection is the central location for communicating with all modules that communicate using a serial data link. The DLC provides a power source and a standard connection for the scan tool.

Refer to Data Link Connector Schematics for circuit information.

Class 2 Serial Data Link

The class 2 serial data link allows a scan tool to communicate with the listed modules for diagnostic and testing purposes. The class 2 serial data link is located at the data link connector (DLC) terminal 2.

    â€¢ Driver information center  (DIC)
    â€¢ Electronic brake control module (EBCM)
    â€¢ Instrument panel cluster (IPC)
    â€¢ Inflatable restraint sensing and diagnostic module (SDM)
    â€¢ Memory seat module (MSM)
    â€¢ Powertrain control module (PCM)
    â€¢ Radio
    â€¢ Theft deterrent control module
    â€¢ Vehicle interface unit (VIU), if equipped

The class 2 serial data link may also be connected to the video disc player and rear video/audio/HVAC module if equipped. However the video disc player and rear video/audio/HVAC module will not communicate with the scan tool, do not set DTCs, and other modules do not set DTCs against them.