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Circuit/System Testing

WARNING: This page is about a different car, the 2008 Pontiac G8. However, it is still accessible from the selected car via links, so may be relevant.
  1. Test for less than 1.0 ohm between the ground circuit terminal 5 of the DLC and ground.
    • If greater than the specified range, test the ground circuit for open/high resistance.
  2. Ignition OFF, disconnect the harness connector at X95.
  3. Ignition ON, test for less than 1 volt between the serial data circuit terminal 1 of the DLC and ground.
    • If greater than the specified range, test the serial data circuit for a short to voltage.
  4. Test for infinite resistance between the serial data circuit terminal 1 of the DLC and ground.
    • If less than the specified value, test the serial data circuit for a short to ground.
  5. Test for less than 2 ohms on the serial data circuit between terminal 1 of the DLC and terminal A of X95.
    • If greater than the specified range, test the serial data circuit for an open/high resistance.
  6. Install a 3-amp fused jumper wire between terminal A and terminal M of X95. Attempt to communicate with the body control module (BCM). Communication should be available.
    • If communication is not available test the serial data line between X95, terminal M and harness connector X3, terminal 10 at the BCM for an open/high resistance.
  7. Install another 3-amp fused jumper wire to terminal A of X95.
    8. IMPORTANT: Allow communications for 5 seconds after connecting a module with the jumper to determine if communication is interrupted or not.
  8. With BCM communications established, use the other end of the jumper wire to connect all other terminals of X95, harness side, one at a time and verify that low speed communication remains available to the BCM.
    • If communication is interrupted after connecting an individual module at X95, test the serial data circuit between X95 and the last module connected for a short to voltage or short to ground. If the circuit tests normal, replace the module that caused no communication.
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