Circuit/System Testing

2006 Chevrolet Chevy Express G2500, Van Cargo, 6.6 2SECTION Circuit/System Testing
WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: 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 Ξ© between the ground circuit terminal 3 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Test for less than 5.0 Ξ© between the ground circuit terminal 12 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Test for less than 5.0 Ξ© between the ground circuit terminal 13 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  5. 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 sunroof control module.
  6. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 2 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, refer to Retained Accessory Power Malfunction .
  7. Ignition OFF, connect the harness connector at the sunroof control module.
  8. Disconnect the harness connector at the sunroof switch.
  9. Test for less than 5.0 Ξ© between the low reference circuit terminal 3 and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the sunroof control module.
  10. Ignition ON, at the sunroof switch harness connector, test for B+ between the following signal circuit terminals and ground:
    • Sunroof switch open signal terminal 1
    • Sunroof switch open vent signal terminal 2
    • Sunroof switch express signal terminal 4
    • If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the sunroof control module.
  11. 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 3 A fused jumper wires between both signal circuits listed below and ground for less than 1 second. The sunroof should express open.
    • Sunroof switch open signal terminal 1
    • Sunroof switch express signal terminal 4
    • If the sunroof did not express open, test the signal circuit terminal 4 for a short to voltage or an open/high resistance. If the circuit tests normal, replace the sunroof control module.
  3. If all circuits test normal, test or replace the sunroof switch.
RENDER: 1.0x

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • β€’ You smell fuel, burning insulation, or see smoke.
  • β€’ Brakes feel soft, pull hard to one side, or make grinding noises.
  • β€’ The engine overheats, stalls repeatedly, or misfires under load.
  • β€’ You are missing required tools, torque specs, or safe lifting equipment.
  • β€’ You are not confident in the next step or safety outcome.