GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 1998 🢒 Chevy P12 Chassis 🢒 Body and Accessories 🢒 Wiring Systems 🢒 Data Link Connector Circuit Description
  1. Data

    2. Two communication lines are used to monitor the modules for diagnostic purposes and to inspect for Diagnostic Trouble Codes (DTCs):

    • The scan tool accesses the PCM through CKT 1807 (PPL).
    • The scan tool accesses the EBCM through CKT 799 (TAN/WHT).
  2. Power

    3. Voltage is applied at all times to the DLC through DATA Fuse 21, by CKT 1340 (ORN).

  3. Ground

    4. The DLC is permanently grounded by two circuits:

    • Signal ground by CKT 451(BLK/WHT) to G102
    • Power ground by CKT 150 (BLK) to G200