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

--

--

Driver Window Switch B+

1,2,3

1,3

--

--

Passenger Window Switch B+

2

2

--

--

Driver Window Motor Ignition

1

1

--

--

Driver Window Motor Control

1

1

1

--

Lockout Switch Control

3

3

--

--

Passenger Window Motor Control

2

2

2

--

Rear Window Motor Control

3

3

3

--

Driver Window Motor Ground

--

1

1

--

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

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 each passenger window UP and DOWN using the window switches on the driver master control and the appropriate passenger door window switch. 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 and depressing 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 up and express down function of the driver door window by pressing and pulling the driver window switch past the first detent and releasing. The driver window should perform the express up and express down function.
  8. If the function does not perform as specified, refer to Power Window Reinitialization .

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 B 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 E 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 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 6 and ground.
  10. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ fuse is open, replace the driver window motor.
  11. Verify that a test lamp illuminates between the ignition circuit terminal 3 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 driver door window DOWN by using the driver window switch. The test lamp should illuminate when commanding the DOWN state.
  15. 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.
    If the test lamp continuously illuminates, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the driver window switch.
  16. Connect a test lamp between the control circuit terminal 2 and ground.
  17. Command the driver door window UP by using the driver window switch. The test lamp should illuminate when commanding the UP state.
  18. 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.
    If the test lamp continuously illuminates, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the driver window switch.
  19. 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 B+ circuit for an open/high resistance
  4. Ignition OFF, test for less than 5 ohms between the control circuit terminal H 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 5 ohms between the control circuit terminal D 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 the control circuit terminal D and control circuit terminal H.
  9. Ignition ON, command the front passenger door window UP and DOWN by using 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 5 ohms 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 5 ohms 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 the 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 either control circuit for a short to ground. 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 5 ohms 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 5 ohms 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 the control circuit terminal D 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 5 ohms 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 5 ohms 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 the 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. 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 harness connector at the driver window switch.
  2. Test for less than 2 ohms between the lockout control terminal F and the B+ terminal E 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 F and the B+ terminal E 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 E:
  7. • Control terminal C
    • Control terminal D
    • Control terminal G
    • Control terminal H
    • Control terminal B
    • Control terminal C
    • Control terminal A
    • Control terminal E
    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 E:
  9. • LR window switch control terminal D
    • RR window switch control terminal G
    • RF window switch control terminal B
    • Driver window switch control terminal E
    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 control terminals listed below and the B+ terminal E:
  11. • LR window switch control terminal C
    • RR window switch control terminal H
    • RF window switch control terminal C
    • Driver window switch control terminal A
    If greater than the specified range, replace the driver window switch.

Front Passenger Window Switch

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

Rear Passenger Window Switch

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Test for infinite resistance between the control terminals G and F and the control terminal A 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 ohms between the control terminal G and the control terminal A 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 F and the control terminal A 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 30A 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
    •  Front Side Door Window Switch Replacement - Right Side
    •  Front Side Door Window Switch Replacement - Left Side