GM Service Manual Online
For 1990-2009 cars only

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The power window/mirror switch supplies power when requested to the front power windows in conjunction with the power window control module (PWCM). The PWCM is a stand alone module, located beneath the instrument panel on the right hand side, it controls the driver and passenger front windows. No communications bus is connected to it, therefore there are no software diagnostics on this module. It is powered directly from the RAP relay, and connected to the window motors. All levels of vehicle have the express down function which is enabled when the power window switch is held down for longer than 0.4 of a second. Higher levels of vehicle also have an express up function which is enabled when the power window switch is lifted for more than 0.4 seconds. The power window/power mirror switch and PWCM power supply is controlled by the RAP (retained accessory power) relay. RAP is delivered via the 2A RAP control fuse to the front power window switch circuit within the power window/power mirror switch and also to the PWCM via the 20A power windows circuit breaker, ground is supplied to the PWCM via ground point G304.

Reference Information

Schematic Reference

Moveable Window Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

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

Circuit/System Verification

  1. Verify that the Retained Accessory Power (RAP) circuit is functioning normally.
  2. If the RAP is not functioning normally refer to Retained Accessory Power (RAP) Description and Operation .
  3. Verify that the driver front window is operating correctly.
  4. If the driver front window is not operating correctly refer to Power Windows Inoperative - One or Both Front Windows .

Circuit/System Testing

  1. Ignition OFF, disconnect the power window/mirror switch harness connector.
  2. Connect a fused jumper wire between supply voltage circuit X2-1 and open signal circuit terminal X2-3
  3. Connect a fused jumper wire between supply ground circuit X2-2 and ground terminal X1-9, ignition ON.
  4. If the window opens replace the power window/mirror switch.
  5. Ignition OFF, disconnect the PWCM harness connector.
  6. Connect a fused jumper wire from the ground circuit terminal 6 to the open return circuit terminal 11 at the PWCM harness connector.
  7. Connect a fused jumper wire from the open input circuit terminal 12 to the open signal circuit terminal 2 at the PWCM harness connector.
  8. Ignition On, press the left front window switch to the Down position and verify that the window opens.
  9. If the window opens replace the PWCM.
  10. Connect a fused jumper wire from the open input circuit terminal 8 to the open signal circuit terminal 2 at the PWCM harness connector.
  11. Connect a fused jumper wire from the ground circuit terminal 5 to the open signal circuit terminal 11 at the PWCM harness connector.
  12. If the window motor does not operate, check if the motor operates in the reverse.
  13. Connect a fused jumper wire from the open input circuit terminal 8 to the open signal circuit terminal 11 at the PWCM harness connector.
  14. Connect a fused jumper wire from the ground circuit terminal 5 to the open signal circuit terminal 2 at the PWCM harness connector.
  15. If the window motor opens/closes, replace the power window/mirror switch.
  16. Test the power/ground supply circuits from the PWCM to the window motor for a short to ground, short to voltage or an open/high resistance.
  17. If all circuits test normal, replace the window motor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Power Mirror Switch Replacement
    •  Front Side Door Window Regulator Motor Replacement .
    •  Front Door Module Replacement .