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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.
  1. Test for less than 1.0 ohm of resistance between the DLC ground circuit terminal 5 and ground.
    • If greater than 1.0 ohm, test the ground circuit for open/high resistance.
  2. Ignition OFF, disconnect the harness connector (splice pack comb) at JX 205. Install a 3-amp fused jumper wire between JX 205 terminal A and terminal M, harness side.
  3. Ignition ON, with a scan tool, attempt to communicate with the body control module (BCM). Communication should be available.
    • If no communication, test the serial data circuit for a short to ground, a short to voltage or an open/high resistance between the BCM and the DLC. If the circuit tests normal, replace the BCM.
  4. Install another 3-amp fused jumper wire to JX 205 terminal A, harness side.
  5. With BCM communications established, use the other end of the jumper wire to connect all other terminals, harness side, one at a time and verify that communication remains available to the BCM.
    IMPORTANT: Allow communications for 5 seconds after connecting a module with the jumper to determine if communication is interrupted or not.
    • If communication is interrupted after connecting an individual module at JX 205, test the serial data circuit between JX 205 and the last module connected for a short to ground and short to voltage. If the circuit tests normal, replace the module that caused no communication.
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