Circuit/System Testing

2008 Chevrolet Chevy Express G3500, Van Passenger ExtendedSECTION Circuit/System Testing
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Driver Power Window Inoperative

  1. Ignition OFF, disconnect the X1 harness connector at the DDS.
  2. Test for less than 15 ohms between the ground circuit terminal 6 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, connect the X1 harness connector at the DDS.
  5. Ignition ON, observe the scan tool Driver LF Window Switch parameters while using the driver power window switch. The parameter should change between Off, Up, Down and Express Down.
    • If the value does not change, replace the DDS.
  6. Ignition OFF, disconnect the harness connector at the driver window motor.
  7. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  8. Ignition ON, command the driver window UP and DOWN by using the driver window switch. The test lamp should illuminate when commanding the UP and DOWN states.
    • If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground or open/high resistance. If the circuits test normal, replace the DDS.
    • If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the DDS
  9. If all circuits test normal, test or replace the driver window motor.

Passenger Power Window Inoperative

  1. Ignition OFF, disconnect the X1 harness connector at the PDS.
  2. Test for less than 1 ohm between the ground circuit terminal 6 and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Ignition OFF, connect the X1 harness connector at the PDS.
  5. Ignition ON, observe the scan tool Passenger Window Switch parameters while using the passenger power window switch. The parameter should change between Off, Up, Down and Express Down.
    • If the value does not change, replace the PDS.
  6. Ignition OFF, disconnect the harness connector at the passenger window motor.
  7. Test for less than 1 ohm between the control circuit terminal A and ground
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PDS.
  8. Test for less than 1 ohm between the control circuit terminal B and ground
    • If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the PDS.
  9. Connect a test lamp between control circuit termina A and control circuit terminal B.
  10. Ignition ON, command the passenger window UP and DOWN by using the passenger window switch. The test lamp should illuminate when commanding the UP and DOWN states.
    • If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground. If the circuits test normal, replace the PDS.
  11. If all circuits test normal, test or replace the passenger window motor.

Rear Power Window Inoperative

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Test for less than 1 ohm between the ground circuit terminal F and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal G and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Enable the rear window switches by pressing the window lockout switch on the driver master control.
  5. Test for greater than 10 volts between the control circuit terminal D and ground.
    • If less than the specified range, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
  6. Test for greater than 10 volts between the signal circuit terminal C and ground while commanding the rear window DOWN with a scan tool.
    • If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
  7. Test for greater than 10 volts between the signal circuit terminal A and ground while commanding the rear window UP with a scan tool.
    • If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
  8. Ignition OFF, connect the harness connector at rear window switch and disconnect the harness connector at the rear window motor.
  9. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
  10. Ignition ON, command the rear window UP and DOWN by using the rear window switch. The test lamp should illuminate when commanding the UP and DOWN states.
    • If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground or open/high resistance. If the circuits test normal, replace the rear window switch.
    • If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the rear window switch.
  11. If all circuits test normal, test or replace the rear window motor.
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