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 Power Window Switch Ignition

1

1

--

--

Passenger Power Window Switch Ignition

1

1

--

--

Driver Power Window Motor Control

1

1

1

--

Passenger Power Window Motor Control

1

1

1

--

Passenger Power Window Master Switch Up Control

1

1

--

--

Passenger Power Window Master Switch Down Control

1

1

--

--

Driver Power Window Switch Ground

--

1

1

--

Passenger Power Window Switch Ground

--

1

1

--

1. Power Windows Malfunction

Circuit/System Description

Battery voltage is applied at all times to the coil and switch terminals of the ACCESSORY relay located in the body control module (BCM). When the ignition is placed in the RUN or ACCESSORY positions, or if retained accessory power (RAP) is active, the BCM grounds the accessory relay coil. This energizes the accessory relay, closing the switch side contacts and provides battery voltage to the WINDOWS fuse through to the driver and passenger power window switches. The power window motor control circuits are connected to ground through the normally closed up and down switch contacts of the power window switches. When a power window switch is placed in the down position, the power window motor down control circuit is switched to 12  volts. The power window motor up control circuit serves as ground and 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

Window Systems Connector End Views

Electrical Information Reference

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

Circuit/System Testing

Power Windows Malfunction

  1. Ignition OFF, disconnect the B+ harness connector at the driver window switch.
  2. Ignition OFF, test for less than 1.0 ohm of resistance 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 C and ground.
  5. If the test lamp does not illuminate, test the B+ circuit for an open/high resistance. If the PWR WNDW fuse is open, test the circuit terminal C for a short to ground.
    If all circuits test normal, test or replace the driver window switch.
  6. Ignition OFF, connect the harness connector at the driver window switch.
  7. Ignition OFF, disconnect the passenger window switch.
  8. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A and ground.
  9. If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
  10. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal H and ground.
  11. 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.
  12. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal D 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, replace the Driver Window switch.
  14. Connect a test lamp between control circuit terminal H and control circuit terminal D.
  15. Ignition ON, command the passenger door window UP and DOWN by pressing the passenger window control on the driver window switch. The test lamp should illuminate during either of the commands.
  16. If the test lamp remains OFF, test for a short to ground or open/high resistance on either control circuit. If all circuits test normal, test or replace the driver window switch.
  17. Ignition OFF, reconnect the passenger window switch.
  18. Ignition OFF, disconnect the harness connector at the appropriate window motor.
  19. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal A and ground.
  20. 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 appropriate window switch.
  21. Ignition OFF, test for less than 1.0 ohm of resistance between the control circuit terminal B and ground.
  22. 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 appropriate window switch.
  23. Connect a test lamp between control circuit terminal A and control circuit terminal B.
  24. Ignition ON, command the appropriate window UP and DOWN by pressing the appropriate window switch. The test lamp should turn ON when commanding the UP and DOWN states.
  25. If the test lamp remains OFF during either of the commands, test for a short to ground or an open/high resistance on either control circuit. If all circuits test normal, test or replace the appropriate power window switch.
  26. If all circuits test normal, test or replace the appropriate power window motor.

Power Window Malfunction- Express Down

  1. Power window inoperative in the express down function is the result of an internal circuit failure of the driver power window switch.
  2. Replace the driver power window switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Front Side Door Window Regulator Replacement
    •  Front Side Door Window Switch Replacement
    •  Control Module References for BCM replacement, setup, and programming