GM Service Manual Online
For 1990-2009 cars only

The Data Link Connector (DLC) contains the following components:

    • The UART serial data line circuit which allows a scan tool to communicate with the following modules for diagnostic and testing purposes:
      • The Powertrain Control Module (PCM)
      • The Electronic Brake Traction Control Module (EBCM) (if equipped with ABS)
      • The trip calculator (if equipped)
      • The heater-A/C control module (if equipped with auto A/C)
    • The Class 2 serial data line circuit which allows a scan tool to communicate with the PCM and inflatable restraint sensing and diagnostic module for diagnostic and testing purposes
    • The Entertainment and Comfort (E&C) serial data line circuit which allows for the communication of data among the following components:
      • The radio
      • The CD player
      • The head-up display