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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 508 (Engine Controls/Fuel - 5.3L, 6.0L, 6.2L - DTC P0420 To DTC P3449 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> DTC P3401, P3425, P3441, or P3449 >> Circuit/System Testing

Circuit/System Testing

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    NOTE:

    If any of the scan tool circuit status parameters displayed "Fault" during the Circuit/System Verification, inspect the wiring harness for signs of binding, chaffing or pinching before intake manifold removal.

  1. Ignition OFF, remove the intake manifold. Refer to Intake Manifold Replacement (RPOs LC9, LMG, LY5, L76) , Intake Manifold Replacement (RPOs LY2, LY6) , Intake Manifold Replacement (Except RPOs LY2, LY6, LC9, LMG, LY5) .
  2. Disconnect the harness connector at the valve lifter oil manifold assembly.
  3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal E and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all the components connected to the ignition circuit and replace as necessary.
  4. Verify that a test lamp does not illuminate between the ignition circuit terminal E and the appropriate cylinder deactivation solenoid control circuit terminal listed below.
    • Cylinder deactivation solenoid valve 1 terminal C
    • Cylinder deactivation solenoid valve 2 terminal A
    • Cylinder deactivation solenoid valve 3 terminal B
    • Cylinder deactivation solenoid valve 4 terminal D
    • If the test lamp illuminates, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  5. Verify that a test lamp does not illuminate between ground and the appropriate cylinder deactivation solenoid control circuit terminal listed below.
    • Cylinder deactivation solenoid valve 1 terminal C
    • Cylinder deactivation solenoid valve 2 terminal A
    • Cylinder deactivation solenoid valve 3 terminal B
    • Cylinder deactivation solenoid valve 4 terminal D
    • If the test lamp illuminates, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Connect a test lamp between the ignition circuit terminal E and the appropriate cylinder deactivation solenoid control circuit terminal listed below.
    • Cylinder deactivation solenoid valve 1 terminal C
    • Cylinder deactivation solenoid valve 2 terminal A
    • Cylinder deactivation solenoid valve 3 terminal B
    • Cylinder deactivation solenoid valve 4 terminal D
  7. Command the appropriate cylinder deactivation solenoid ON with a scan tool. Verify the test lamp illuminates with each command.
    • If the test lamp does not illuminate, test the control circuit for an open/high resistance. If the circuit tests normal, replace the ECM.
  8. If all the circuits test normal, test or replace the valve lifter oil manifold assembly.
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