GM Service Manual Online
For 1990-2009 cars only

There are 2 data lines that are accessed by the scan tool. The following data lines are accessed through the PPL/WHT wire at the data link connector -- on-board diagnostics II (DLC-OBD II) at cavity 9:

    • The electronic brake control module (EBCM), if equipped
    • The inflatable restraint sensing and diagnostic module (SDM)

The PPL/GRN wire accesses the powertrain control module (PCM) at the DLC-OBD II at cavity 7.

The communication lines monitor the modules for diagnostic purposes, and to inspect for diagnostic trouble codes (DTCs). The TAIL DOME fuse applies voltage at all times to the DLC-OBD II. The DLC-OBD II permanently grounds to the following wires:

    • G202 (body ground)
    • G103 (engine ground)