GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Driver Window Motor B+

1

1

--

--

LR Window Motor B+

2

2

--

--

Passenger Window Motor B+

1

1

--

--

RR Window Motor B+

2

2

--

--

Driver Window Motor Ignition

1

1

--

--

LR Window Motor Ignition

2

2

--

--

Passenger Window Motor Ignition

1

1

--

--

RR Window Motor Ignition

2

2

--

--

Door Lock/Window Switch Ignition

2

2

--

--

Rear Switch Window Signal

2

2

2

--

Rear Window Lockout Control

2

2

--

--

Driver Window Motor Control

1

1

1

--

Passenger Window Motor Control

2

2

2

--

Rear Window Motor Control

2

2

2

--

Driver Window Motor Ground

--

1

1

--

LR Window Motor Ground

--

2

2

--

Passenger Window Motor Ground

--

1

1

--

RR Window Motor Ground

--

2

2

--

Door Lock/Window Switch Ground

--

2

2

--

1. Front Window Malfunction

2. Rear Windows Malfunction

Circuit/System Description

When the ignition switch is in the RUN or ACCY position, or retained accessory power (RAP) is enabled and the window switch is pressed in the down position, a voltage signal is sent to the window motor commanding the window to open. When the window switch is pulled in the up position, a voltage signal is sent to the window motor commanding the window to close. The door lock/window switch controls the driver, passenger and rear windows.

When the ignition switch is in the RUN or ACCY position, or RAP is enabled and the lockout switch is disengaged, battery positive voltage will be available at the rear window switches. When an individual window switch is pressed in the down or pulled in the up position, a voltage signal is sent to the window motor commanding the window to open or close.

Reference Information

Schematic Reference

Moveable Window Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Windows Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Verification

  1. Ignition ON, command the windows UP and DOWN using the window switches on the door lock/window switch, the right rear window switch and the left rear window switch. Each window should perform the UP and DOWN functions from each switch.
  2. If a front window does not perform the UP/DOWN function, refer to Front Window Malfunction.
    If either rear window does not perform the UP/DOWN function, refer to Rear Window Malfunction.
  3. Disable and enable the rear window door switches by pressing and depressing the lockout switch on the door lock/window switch. The rear window switches should be enabled and disabled when changing between the commanded states.
  4. If the rear window switches continue to function while disabled, refer to Lockout Switch Malfunction.
  5. Command each window to EXPRESS UP and EXPRESS DOWN by using each door lock/window switch. Each window should perform the EXPRESS UP and EXPRESS DOWN functions.
  6. If a window does not perform EXPRESS UP and EXPRESS DOWN function, refer to Express Feature Malfunction.

Circuit/System Testing

Front Window Malfunction

  1. Ignition OFF, disconnect the X1 and X2 harness connectors at the door lock/window switch.
  2. Test for less than 1 Ω between the ground circuit terminal 4 and ground.
  3. If greater than the specified range, test the ground circuit for an open/high resistance.
  4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 3 and ground.
  5. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  6. Ignition OFF, connect the X1 and X2 harness connectors at the door lock/window switch and disconnect the harness connector at the appropriate front window motor.
  7. Test for less than 1 Ω between the ground circuit terminal 4 and ground.
  8. If greater than the specified range, test the ground circuit for an open/high resistance.
  9. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
  10. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  11. Verify that a test lamp illuminates between the ignition circuit terminal 2 and ground.
  12. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  13. Connect a test lamp between the control circuit terminal 1 and ground.
  14. Ignition ON, command the front window UP by using the appropriate window switch on the door lock/window switch. The test lamp should illuminate when commanding the UP state.
  15. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the door lock/window switch.
    If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the door lock/window switch.
  16. Connect a test lamp between the control circuit terminal 6 and ground.
  17. Command the front window DOWN by using the window switch on the door lock/window switch. The test lamp should illuminate when commanding the DOWN state.
  18. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the door lock/window switch.
    If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the door lock/window switch.
  19. If all circuits test normal, replace the front window motor.

Rear Window Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Note: Verify the rear window switches are enabled by checking the lockout switch on the door lock/window switch.

  3. Ignition ON, verify that a test lamp illuminates between the control circuit terminal 7 and ground.
  4. If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the door lock/window switch.
  5. Connect a test lamp between the signal circuit terminal 4 and the signal circuit terminal 5.
  6. Ignition ON, command the rear window UP and DOWN using the appropriate window switch on the door lock/window switch. The test lamp should illuminate when commanding the UP and DOWN states.
  7. If the test lamp does not illuminate during either of the commands, test either signal circuit for a short to ground or an open/high resistance. If the circuits test normal, test or replace the door lock/window switch.
    If the test lamp is always ON, test either signal circuit for a short to voltage. If the circuits test normal, test or replace the door lock/window switch.
  8. Ignition OFF, connect the harness connector at the rear window switch and disconnect the harness connector at the rear window motor.
  9. Test for less than 1 Ω between the ground circuit terminal 4 and ground.
  10. If greater than the specified range, test the ground circuit for an open/high resistance.
  11. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
  12. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  13. Verify that a test lamp illuminates between the ignition circuit terminal 2 and ground.
  14. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  15. Connect a test lamp between the control circuit terminal 1 and ground.
  16. Ignition ON, command the rear window UP by using the rear window switch. The test lamp should illuminate when commanding the UP state.
  17. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the rear window switch.
    If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the rear window switch.
  18. Connect a test lamp between the control circuit terminal 6 and ground.
  19. Command the rear window DOWN by using the rear window switch. The test lamp should illuminate when commanding the DOWN state.
  20. If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the rear window switch.
    If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the rear window switch.
  21. If all circuits test normal, replace the rear window motor.

Lockout Switch Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Connect a test lamp between the control circuit terminal 7 and ground.
  3. Command the rear window lockout ON and OFF by pressing and depressing the lockout switch on the door lock/window switch. The test lamp should turn ON and OFF when changing between the commanded states.
  4. If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the door lock/window switch.
    If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the door lock/window switch.
  5. If all circuits test normal, test or replace the rear window switch.

Express Feature Malfunction

  1. Ignition ON, command the appropriate power window fully UP by lifting and holding the appropriate window switch for 5 seconds.
  2. Command the power window fully DOWN by pressing and holding the window switch for 5 seconds.
  3. Command the express up and express down functions of the window by pressing the window switch past the first detent and releasing and pulling the window switch past the first detent and releasing. The power window should perform the express up and express down function.
  4. If the function does not perform as specified, replace the window motor.

Component Testing

Door Lock/Window Switch

  1. Ignition OFF, disconnect the X1 and X2 harness connectors at the door lock/window switch.
  2. Test for less than 2 Ω between the control terminal 4 and the ignition terminal 3 with the lockout switch in the ENABLE position.
  3. If greater than the specified range, replace the door lock/window switch.
  4. Test for infinite resistance between the control terminal 4 and the ignition circuit terminal 3 with the lockout switch in the DISABLE position.
  5. If less than the specified value, replace the door lock/window switch.
  6. With the switch in the INACTIVE position, test for infinite resistance between the ignition terminal 3 and the signal terminal listed below:
  7. • Signal terminal 1
    • Signal terminal 7
    • Signal terminal 6
    • Signal terminal 12
    • Signal terminal 8
    • Signal terminal 9
    • Signal terminal 10
    • Signal terminal 11
    If less than the specified value, replace the door lock/window switch.
  8. With the switch in the UP position, test for less than 2 Ω between the ignition terminal 3 and the signal terminals listed below:
  9. • LR window switch signal terminal 8
    • RR window switch signal terminal 11
    • RF window switch signal terminal 1
    • LF window switch signal terminal 6
    If greater than the specified range, replace the door lock/window switch.
  10. With the switch in the DOWN position, test for less than 2 Ω between the ignition terminal 3 and the signal terminal listed below:
  11. • LR window switch signal terminal 9
    • RR window switch signal terminal 10
    • RF window switch signal terminal 7
    • LF window switch signal terminal 12
    If greater than the specified range, replace the door lock/window switch.

Rear Window Switch

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Test for infinite resistance between the signal terminals 1 and 8 and the control terminal 7 with the switch in the INACTIVE position.
  3. If less than the specified value, replace the rear window switch.
  4. Test for less than 2 Ω between the signal terminal 8 and the control terminal 7 with the switch in the UP position.
  5. If greater than the specified range, replace the rear window switch.
  6. Test for less than 2 Ω between the signal terminal 1 and the control terminal 7 with the switch in the DOWN position.
  7. If greater than the specified range, replace the rear window switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Front Side Door Window Regulator Motor Replacement
    •  Rear Side Door Window Regulator Motor Replacement
    •  Rear Side Door Window Switch Replacement