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 Switch Ignition

3

3

--

--

Rear Window Switch Signal

2

2

2

--

Lockout Switch Control

2

2

2

--

Front Window Motor Control

1

1

1

--

Rear Window Motor Control

2

2

2

--

Driver Window Switch Ground

--

3

3

--

1. Front Power Window Malfunction

2. Rear Power Window Malfunction

3. All Power Windows Inoperative

Circuit/System Description

The power window system will operate any time the ignition is the ACC or RUN position. The power window system will also operate whenever the BCM is in retained accessory power (RAP) mode. The master window switch contains individual window switches for each power window. All windows may be controlled up and down from the master window switch. The individual rear window switches will only control the up and down operation of their respective power window.

Each power window contains a reversible power window motor. The direction the window travels is dependent upon the polarity of the supply voltage. By reversing polarity of the supply voltage the window motor will move up or down. Each power window motor is internally circuit breaker protected.

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 each window UP and DOWN using the window switches on the master control and each 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 or DOWN function, refer to Front Window Malfunction.
    If either rear power windows do not perform the UP or 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 master window switch. The rear window switches should be enabled and disabled when changing between the commanded states.
  4. If both rear window switches continue to function while disabled, refer to Lockout Switch Malfunction.
  5. Command the express down function of the driver door window by pressing the left front window switch past the first detent and releasing. The driver window should perform the express down function.
  6. If the function does not perform as specified, replace the master window switch.

Circuit/System Testing

Front Window Malfunction

  1. Ignition OFF, disconnect the X2 harness connector at the master window switch.
  2. Test for less than 1 ohm between the ground circuit terminal 6 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 1 and ground.
  5. If the test lamp does not illuminate, test the igntion circuit for a short to ground or an open/high resistance.
  6. Ignition OFF, connect the harness connector at the master window switch and disconnect the harness connector at the appropriate front window motor.
  7. Test for less than 1 ohm between the control circuit terminal listed below and ground:
  8. • Terminal 1
    • Terminal 2
    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, test or replace the master window switch.
  9. Ignition ON, connect a test lamp between the control circuit terminal 1 and control circuit terminal 2.
  10. Command the window UP and DOWN by using the appropriate window switch on the master control. The test lamp should illuminate when commanding the UP and DOWN states.
  11. If the test lamp remains OFF during either of the commands, test either control circuit for a short to ground. If the circuits test normal, test for replace the master window switch.
  12. If all circuits test normal, test or replace the front window motor.

Rear Window Malfunction

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

  3. Ignition ON, verify that a test lamp illuminates between the control circuit terminal 5 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 master window switch.
  5. Ignition OFF, test for less than 1 ohm between the signal circuit terminal 2 and ground.
  6. If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the master window switch.
  7. Test for less than 1 ohm between the signal circuit terminal 6 and ground.
  8. If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the master window switch.
  9. Connect a test lamp between the signal circuit terminal 2 and the signal circuit terminal 6.
  10. Ignition ON, command the rear passenger door window UP and DOWN by using the appropriate master window switch. The test lamp should illuminate when commanding the UP and DOWN states.
  11. If the test lamp remains OFF during either of the commands, test both signal circuits for a short to ground. If the circuits test normal, test or replace the master window switch.
  12. Ignition OFF, connect the harness connector at the rear window switch and disconnect the harness connector at the rear window motor.
  13. Test for less than 1 ohm between the control circuit terminal 2 and ground.
  14. 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, test or replace the rear door window switch.
  15. Test for less than 1 ohm between the control circuit terminal 1 and ground.
  16. 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, test or replace the rear door window switch.
  17. Connect a test lamp between the control circuit terminal 1 and control circuit terminal 2
  18. 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.
  19. If the test lamp remains OFF during either of the commands, test either control circuit for a short to ground. If the circuits test normal, test or replace the rear window switch.
  20. If all circuits test normal, test or 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 5 and ground
  3. Ignition ON, command the rear window lockout ON and OFF by pressing and depressing the lockout switch on the master 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, replace the master 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, replace the master window switch.
  5. If all circuits test normal, replace the rear window switch.

Component Testing

Master Window Switch

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

Window Motor

  1. Ignition OFF, disconnect the harness connector at the appropriate window motor.
  2. Install a 25A fused jumper wire between one of the control terminals and 12V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the window motor should perform the UP/DOWN functions.
  3. If it does not perform as specified, replace the window motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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