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 B+

1,3

1,3

--

--

Passenger Window Switch B+

2

2

--

--

Lockout Switch Control

3

3

--

--

Driver Window Motor Control

1

1

1

--

Passenger Window Motor Control

2

2

2

--

Rear Window Motor Control

3

3

3

--

Driver Window Switch Ground

--

1, 2, 3

1, 2, 3

--

1. Driver Window Malfunction

2. Passenger Window Malfunction

3. 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 driver or passenger window switch is pressed in the down position, voltage is applied to the appropriate window motor causing that window to open. When the driver or passenger window switch is pulled in the up position, voltage is applied to the appropriate window motor in the opposite direction causing that window to close.

The driver master control contains a rear window lockout switch which disconnects the battery positive voltage supply to both rear passenger door window switches, disabling them. The RR and LR window switches on the driver master control will continue to function normally.

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

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

  1. Ignition ON, command the driver window UP and DOWN using the driver window switch. The driver window should perform the UP and DOWN functions.
  2. If the driver window does not perform the UP/DOWN function, refer to Driver Window Malfunction.
  3. Command the each passenger window UP and DOWN using the appropriate window switch on the driver master control and the appropriate passenger door window switch. The each passenger window should perform the UP and DOWN functions from each switch.
  4. If the front passenger window does not perform the UP/DOWN function, refer to Front Passenger Window Malfunction.
    If either rear power windows do not perform the UP/DOWN function, refer to Rear Window Malfunction.
  5. Disable and enable the rear window door switches by pressing the lockout switch on the driver master control. The rear door power window switches should be enabled and disabled when changing between the commanded states.
  6. If both rear window switches continue to function while disabled, refer to Lockout Switch Malfunction.
  7. Command the express down of the driver door window by pressing the driver window switch past the first detent and releasing. The driver window should perform the express down function.
  8. If the function does not perform as specified, replace the driver window switch.

Circuit/System Testing

Driver Window Malfunction

  1. Ignition OFF, disconnect the X1 harness connector at the driver window switch.
  2. Test for less than 1 ohm between the ground circuit terminal E 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 B+ circuit terminal B and ground.
  5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  6. Ignition OFF, connect the harness connector at the driver window switch and disconnect the harness connector at the driver window motor.
  7. Test for less than 1 ohm between the control circuit terminal A and ground.
  8. 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 driver window switch.
  9. Test for less than 1 ohm between the control circuit terminal B and ground.
  10. 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 driver window switch.
  11. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  12. Ignition ON, command the driver door window UP and DOWN using the driver window switch. The test lamp should illuminate when commanding the UP and DOWN states.
  13. If the test lamp does not illuminate during either of the commands, test both control circuits for a short to ground. If the circuits test normal, test or replace the driver window switch.
  14. If all circuits tests normal, test or replace the driver window motor.

Front Passenger Window Malfunction

  1. Ignition OFF, disconnect the harness connector at the front passenger window switch.
  2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A and ground.
  3. If the test lamp does not illuminate, test the ignition circuit for an open/high resistance
  4. Ignition OFF, test for less than 1 ohm between the control circuit terminal D and ground.
  5. 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 driver window switch.
  6. Test for less than 1 ohm between the control circuit terminal H and ground.
  7. 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 driver window switch.
  8. Connect a test lamp between control circuit terminal D and control circuit terminal H.
  9. Ignition ON, command the front passenger door window UP and DOWN by operating the RF window switch on the driver master control. The test lamp should illuminate when commanding the UP and DOWN states.
  10. If the test lamp does not illuminate during either of the commands, test both control circuits for a short to ground. If the circuits test normal, test or replace the driver window switch.
  11. Ignition OFF, connect the harness connector at the front passenger window switch and disconnect the harness connector at the front passenger window motor.
  12. Test for less than 1 ohm between the control circuit terminal A and ground.
  13. 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 front passenger window switch.
  14. Test for less than 1 ohm between the control circuit terminal B and ground.
  15. 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 front passenger window switch.
  16. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  17. Ignition ON, command the front passenger door window UP and DOWN using the passenger window switch. The test lamp should illuminate when commanding the UP and DOWN states.
  18. If the test lamp does not illuminate during either of the commands, test for a short to ground on either control circuit. If the circuits test normal, test or replace the front passenger window switch.
  19. If all circuits test normal, test or replace the front passenger window motor.

Rear Window Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Ignition ON, with the lockout switch closed, verify that a test lamp illuminates between the control circuit terminal A and ground.
  3. 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 driver window switch.
  4. Ignition OFF, test for less than 1 ohm between the control circuit terminal D and ground.
  5. 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 driver window switch.
  6. Test for less than 1 ohm between the control circuit terminal H and ground.
  7. 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 driver window switch.
  8. Connect a test lamp between control circuit terminal C and control circuit terminal H.
  9. Ignition ON, command the rear passenger door window UP and DOWN using the window switch on the driver master control. The test lamp should illuminate when commanding the UP and DOWN states.
  10. If the test lamp does not illuminate during either of the commands, test both control circuits for a short to ground. If the circuits test normal, test or replace the driver window switch.
  11. Ignition OFF, connect the harness connector at the rear window switch and disconnect the harness connector at the rear window motor.
  12. Test for less than 1 ohm between the control circuit terminal A and ground.
  13. 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 window switch.
  14. Test for less than 1 ohm between the control circuit terminal B and ground.
  15. 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 window switch.
  16. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  17. Ignition ON, command the rear window UP and DOWN using the rear window switch. The test lamp should illuminate when commanding the UP and DOWN states.
  18. If the test lamp does not illuminate during either of the commands, test both control circuits for a short to ground. If the circuits test normal, test or replace the rear window switch.
  19. 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 A and ground.
  3. Ignition ON, command the rear window lockout ON and OFF by pressing and depressing the lockout switch on the driver master control. 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 test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance.
  5. If all circuits test normal, test or replace the driver window switch.

Component Testing

Driver Window Switch

  1. Ignition OFF, disconnect the X1 and X2 harness connectors at the driver window switch.
  2. Test for less than 2 ohms between the lockout control terminal D and the B+ terminal B with the lockout switch in the ENABLE position.
  3. If greater than the specified value, replace the driver window switch
  4. Test for infinite resistance between the lockout control terminal D and the B+ circuit terminal B with the lockout switch in the DISABLE position.
  5. If less than the specified value, replace the driver window switch.
  6. With the switch in the INACTIVE position, test for infinite resistance between the control terminals listed below and the B+ terminal B:
  7. • LR window switch control terminals E and F
    • RR window switch control terminals G and H
    • RF window switch control terminals B and A
    • Driver window switch control terminals C and D
    If less than the specified value, replace the driver window switch.
  8. With the switch in the UP position, test for less than 2-ohms between the control terminals listed below and the B+ terminal B:
  9. • LR window switch control terminal E
    • RR window switch control terminal G
    • RF window switch control terminal B
    • Driver window switch control terminal C
    If greater than the specified range, replace the driver window switch.
  10. With the switch in the DOWN position, test for less than 2-ohms between the appropriate control terminals and the B+ terminal B listed below:
  11. • LR window switch control terminal F
    • RR window switch control terminal H
    • RF window switch control terminal A
    • Driver window switch control terminal D
    If greater than the specified range, replace the driver window switch.

Passenger or Rear Window Switch

  1. Ignition OFF, disconnect the harness connector at the window switch.
  2. Test for infinite resistance between the control terminals F and G and the control terminal A 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 F and the control terminal A with the switch in the UP position.
  5. If greater than the specified range, replace the window switch.
  6. Test for less than 2 ohms between the control terminal G and the control terminal A with the switch in the DOWN position.
  7. If greater than the specified range, replace the window switch

Rear Passenger Window Switch

  1. Ignition OFF, disconnect the harness connector at the appropriate window switch.
  2. Test for infinite resistance between the control terminals D and A and the control terminal E 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 D and the control terminal E with the switch in the UP position.
  5. If greater than the specified range, replace the window switch.
  6. Test for less than 2 ohms between the control terminal A and the control terminal E with the switch in the DOWN position.
  7. If greater than the specified range, replace the window switch

Window Motor

  1. Ignition OFF, disconnect the harness connector at the appropriate window motor.
  2. Install a 25-amp fused jumper wire between the control terminal A and 12 volts. Momentarily install a jumper wire between the control terminal B and ground. The window motor should perform the UP/DOWN function.
  3. If the function does not perform as specified, replace the window motor.
  4. Reverse the jumper wires; the window motor should perform the DOWN/UP function.
  5. If the function 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 Regulator Motor Replacement
    •  Rear Side Door Window Regulator Motor Replacement
    •  Rear Side Door Window Switch Replacement