Circuit/System Testing

2006 Isuzu Ascender S, 4.2 S, 4WDSECTION Circuit/System Testing
WARNING: This page is about a different car, the 2008 Saab 9-7X. However, it is still accessible from the selected car via links, so may be relevant.

Driver Window Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the DDM.
  2. Test for less than 1.0 ohm between the ground circuit terminal A 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 D and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or open/high resistance.
  4. Ignition OFF, reconnect the harness connector at the DDM.
  5. Ignition ON, observe the scan tool Driver Window Switch parameters while using the driver power window switch. The reading should change between OFF/UP/DOWN/EXPRESS DOWN.
    • If the parameter does not change, replace the DDM.
  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 turn ON when commanding the UP and DOWN states.
    • If the test lamp is always OFF during either of the commands, test for a short to ground or open/high resistance on either control circuit. If the circuits test normal, replace the DDM.
    • If the test lamp is always ON, test for a short to voltage on either control circuit. If the circuits test normal, replace the DDM.
  9. If all circuits test normal, test or replace the driver window motor.

Passenger Window Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the FPDM.
  2. Test for less than 1.0 ohm between the ground circuit terminal A 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 D and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or open/high resistance.
  4. Ignition OFF, reconnect the harness connector at the FPDM.
  5. Ignition ON, observe the scan tool Psgr RF Window Switch parameters while using the passenger power window switch. The reading should change between OFF/UP/DOWN/EXPRESS DOWN.
    • If the parameter does not change, replace the FPDM.
  6. Ignition OFF, disconnect the harness connector at the passenger window motor.
  7. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  8. Ignition ON, command the passenger window UP and DOWN by using the passenger window switch. The test lamp should turn ON when commanding the UP and DOWN states.
    • If the test lamp is always OFF during either of the commands, test for a short to ground or open/high resistance on either control circuit. If the circuits test normal, replace the FPDM.
    • If the test lamp is always ON, test for a short to voltage on either control circuit. If the circuits test normal, replace the FPDM.
  9. If all circuits test normal, test or replace the passenger window motor.

Rear Passenger Window Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Test for less than 1.0 ohm between the ground circuit terminal E 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 A and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  4. Test for more than 10 volts between the power window lockout rear control circuit terminal D and ground with the rear windows enabled on the driver master control.
    • 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
  5. Connect a test lamp between the power window switch rear down signal circuit terminal B and B+.
  6. Command the appropriate rear window DOWN with a scan tool. The test lamp should turn ON when commanding the DOWN state.
    • If the test lamp is always OFF, test the signal circuit for a short to voltage or open/high resistance. If the circuits test normal, replace the BCM.
  7. Connect a test lamp between the power window switch rear up signal circuit terminal C and B+.
  8. Command the appropriate rear window UP with a scan tool, the test lamp should turn ON when commanding the UP state.
    • If the test lamp is always OFF, test the signal circuit for a short to voltage or open/high resistance. If the circuits test normal, replace the BCM.
  9. Ignition OFF, reconnect the appropriate rear window switch and disconnect the harness connector at the appropriate rear window motor.
  10. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  11. Ignition ON, command the appropriate rear window UP and DOWN by using the appropriate rear window switch. The test lamp should turn ON 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 appropriate 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 appropriate rear window switch.
  12. If all circuits test normal, test or replace the appropriate rear window motor.
RENDER: 1.0x

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

  • β€’ You smell fuel, burning insulation, or see smoke.
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