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, 2, 3, 4

1

--

--

Passenger Window Switch B+

1, 2, 3, 4

2

--

--

LR Window Switch B+

1, 2, 3, 4

3

--

--

RR Window Switch B+

1, 2, 3, 4

4

--

--

LR Window Down Signal

1, 2, 3, 4

3

3

--

LR Window Up Signal

1, 2, 3, 4

3

3

--

Passenger Window Down Signal

1, 2, 3, 4

2

2

--

Passenger Window Up Signal

1, 2, 3, 4

2

2

--

RR Window Down Signal

1, 2, 3, 4

4

4

--

RR Window Up Signal

1, 2, 3, 4

4

4

--

Window Master Switch Lockout Control

1, 2, 3, 4

3, 4

3, 4

--

Driver Window Motor Control

1

1

1

--

Passenger Window Motor Control

2

2

2

--

LR Window Motor Control

3

3

3

--

RR Window Motor Control

4

4

4

--

Driver Window Switch Ground

--

1,3,4

1

--

Passenger Window Switch Ground

--

2

2

--

LR Window Switch Ground

--

3

3

--

RR Window Switch Ground

--

4

4

--

1. Driver Power Window Malfunction

2. Front Passenger Window Malfunction

3. Left Rear Power Window Malfunction

4. Right Rear Power Window Malfunction

Circuit/System Description

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.

Battery voltage is supplied to each power window switch through the accessory voltage supply circuit. The power window switch also receives a constant ground source. The power window motor control circuits are connected to ground through the normally closed up and down contacts of the power window switch. When the power switch is placed in the down position, the power window motor down control circuit is switched to 12V and is applied to the down side of the power window motor. Since the other side of the power motor is connected to ground through the normally closed contacts of the up switch, the window travels down. By placing the power window switch in the up position, the polarity of the power window motor is reversed and the window travels up.

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 each window UP and DOWN using the window switches on the driver master control and by using their respective door window switches. Each window should perform the UP and DOWN functions from each switch.
  2. If the driver door window is inoperative, refer to Driver Power Window Inoperative.
    If the passenger door window is inoperative, refer to Passenger Power Window Inoperative
    If the left rear or right rear door window is inoperative, refer to Rear Power Window Malfunction.
  3. Disable the rear window switches by activating the window lockout switch on the driver master control. The rear power windows should be inoperative from the rear door window switches.
  4. If the rear window switches are still active, refer to Rear Window Lockout Malfunction.
  5. Command the express down function of the driver door window by pressing down on the driver’s window switch past the first detent and releasing. The driver’s window should roll completely down.
  6. If the function does not perform as specified, replace the driver window switch.

Circuit/System Testing

Driver Power Window Inoperative

  1. Ignition OFF, disconnect the X2 harness connector at the driver window switch.
  2. Test for less than 1 ohm between the ground circuit terminal A 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 H 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. Verify that a test lamp illuminates between the ignition circuit terminal G and ground.
  7. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance
  8. Connect the X2 harness connector at the driver window switch. Disconnect the harness connector at the driver window motor.
  9. Test for less than 1 ohm between the control circuit terminal listed below and ground:
  10. • Terminal A
    • Terminal B
    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, replace the driver window switch.
  11. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
  12. Command the driver window UP and DOWN by using the driver window switch. The test lamp should illuminate when commanding the UP and DOWN states.
  13. 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, replace the driver window switch.
  14. If all circuits test normal, test or replace the driver window motor.

Passenger Power Window Inoperative

  1. Ignition OFF, disconnect the harness connector at the passenger window switch.
  2. Test for less than 1 ohm between the ground circuit terminal F 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 G 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. Verify that a test lamp illuminates between the ignition circuit terminal D and ground.
  7. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  8. Connect a test lamp between the signal circuit terminal C and ground.
  9. Command the passenger window DOWN using the RF window switch on the driver master control, the test lamp should illuminate during the DOWN command.
  10. If the test lamp is always OFF, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the driver window switch.
    If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the driver window switch.
  11. Connect a test lamp between the signal circuit terminal A and ground.
  12. Command the passenger window UP using the RF window switch on the driver master control, the test lamp should illuminate during the UP command.
  13. If the test lamp is always OFF, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the driver window switch.
    If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the driver window switch.
  14. Ignition OFF, connect the harness connector passenger window switch and disconnect the harness connector at the passenger window motor.
  15. Test for less than 1 ohm between the control circuit terminal listed below and ground:
  16. • Terminal A
    • Terminal B
    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, replace the passenger window switch.
  17. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
  18. Command the passenger window UP and DOWN by using the passenger 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, replace the passenger window switch.
  20. If all circuits test normal, test or replace the passenger window motor.

Rear Power Window Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Test for less than 1 ohm between the ground circuit terminal F 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 G and ground.
  5. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

    Note: Check the lockout switch on the driver door switch and verify the rear window switches are enabled.

  6. Verify that a test lamp illuminates between the control circuit terminal D and ground.
  7. If the test lamp does not illuminate, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the driver window switch.
  8. Connect a test lamp between the signal circuit terminal C and ground.
  9. Command the rear window DOWN using the appropriate window switch on the driver master control, the test lamp should illuminate during the DOWN command.
  10. If the test lamp is always OFF, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the driver window switch.
    If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the driver window switch.
  11. Connect a test lamp between the signal circuit terminal A and ground.
  12. Command the rear window UP using the window switch on the driver master control, the test lamp should illuminate during the UP command.
  13. If the test lamp is always OFF, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the driver window switch.
    If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit tests normal, replace the driver window switch.
  14. Ignition OFF, connect the harness connector at rear window switch and disconnect the harness connector at the rear window motor.
  15. Test for less than 1 ohm between the control circuit terminal listed below and ground.
  16. • Terminal A
    • Terminal B
    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, replace the rear window switch.
  17. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
  18. 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, replace the rear window switch.
  20. If all circuits test normal, test or replace the rear window motor.

Rear Window Lockout Malfunction

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Connect a test lamp between the control circuit terminal D 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 circuit tests normal, replace the driver 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 driver window switch.
  5. If all circuits test normal, replace the rear window switch.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate window motor.
  2. Install a 30A 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.

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