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Home >> Hummer >> 2008 >> H2 4D Utility Wagon >> Repair and Diagnosis >> External Pages >> Different car >> Section 448 (Sunroof System) >> Diagnostic Information and Procedures >> Power Sunroof Malfunction >> Circuit/System Testing

Circuit/System Testing

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IMPORTANT:

Because of the accessibility of the sunroof switch, perform the sunroof switch component test before beginning the Circuit/System Testing.

Power Sunroof Malfunction

  1. Ignition OFF, disconnect the harness connector at the sunroof control module.
  2. Test for less than 5.0 ohm between the ground circuit terminal 2 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Verify that a test lamp illuminates between the B+ circuit terminal 1 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, replace the fuse and replace the sunroof control module.
  4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground.
  5. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 6 and ground.
  6. Ignition OFF, connect the harness connector at the sunroof control module.
  7. Disconnect the harness connector at the sunroof switch.
  8. Test for less than 5.0 ohm between the ground circuit terminal 5 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
    9. IMPORTANT:

    Apply ground to the module for no longer than 2 seconds at a time or the module could be damaged.

    When performing the following tests, make sure that the sunroof or sunshade is not at its end of travel position by switching the grounded jumper to the other signal circuit if the sunroof or sunshade does not move in one direction.

  9. Ignition ON, momentarily install a 10-amp fused jumper wire between the signal circuit terminal 6 and ground. The sunroof should move.
    • If the sunroof does not move, test the signal circuit for a short to ground, short to voltage or an open/high resistance. If the circuit test is normal, replace the sunroof control module.
  10. Momentarily install a 10-amp fused jumper wire between the signal circuit terminal 4 and ground. The sunroof should move.
    • If the sunroof does not move, test the signal circuit for a short to ground, short to voltage or an open/high resistance. If the circuit test is normal, replace the sunroof control module.
  11. With the sunroof in the fully closed position, momentarily install a 10-amp fused jumper wire between the signal circuit terminal 2 and ground. The sunroof should vent open.
    • If the sunroof does not vent open, test the signal circuit for a short to ground, short to voltage or an open/high resistance. If the circuit test is normal, replace the sunroof control module.
  12. Momentarily install a 10-amp fused jumper wire between the signal circuit terminal 8 and ground. The sunroof should close.
    • If the sunroof does not close, test the signal circuit for a short to ground, short to voltage or an open/high resistance. If the circuit test is normal, replace the sunroof control module.
  13. If all circuits test normal, test or replace the sunroof switch.

Power Sunroof Express Feature Malfunction

  1. Ignition OFF, disconnect the harness connector at the sunroof switch.
  2. Ignition ON, with the sunroof in the closed position, connect a 3-amp fused jumper wires between both signal circuits listed below and ground for less than 1 second. The sunroof should express open.
    • Terminal 1
    • Terminal 6
    • If the sunroof does not express open, test the signal circuit terminal 1 for a short to voltage or an open high resistance. If the circuit tests normal, replace the sunroof control module.
  3. Ignition ON, with the sunroof in the open position, connect a 3-amp fused jumper wire between both signal circuits listed below and ground for less than 1 second. The roof should express close.
    • Terminal 1
    • Terminal 4
    • If the roof does not express close, test the signal circuit terminal 1 for a short to voltage or an open high resistance. If the circuit tests normal, replace the sunroof control module.
  4. If all circuits test normal, test or replace the sunroof switch.
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