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

DDS B+

1

1

--

--

LR Window Switch B+

3

3

--

--

PDS B+

2

2

--

--

RR Window Switch B+

4

4

--

--

LR Window Motor Control

3

3

3

--

RR Window Motor Control

4

4

4

--

Window Master Switch LR Down Control

B3820 00

B3820 00

B3820 00

--

LR Window Master Switch Lockout Control

B3821 00

B3821 00

B3821 00

--

RR Window Master Switch Lockout Control

B3824 00

B3824 00

B3824 00

--

Window Master Switch LR Up Control

B3819 00

B3819 00

B3819 00

--

Window Master Switch RR Down Control

B3823 00

B3823 00

B3823 00

--

Window Master Switch RR Up Control

B3822 00

B3822 00

B3822 00

--

LR Window Switch Ground

--

3

3

--

RR Window Switch Ground

--

4

4

--

1. Driver Window Malfunction

2. Passenger Window Malfunction

3. Left Rear Window Malfunction

4. Right Rear Window Malfunction

Circuit/System Description

The body control module (BCM) monitors the window UP/DOWN command from the driver door switch (DDS). When the rear window UP or DOWN command is received, the BCM sends a signal to the appropriate rear window switch. The rear window switches continuously monitor the up and down signal circuits, if no function is being commanded, the signal voltage is at approximately B+ voltage. If the UP or DOWN function is commanded, the BCM signal voltage drops approximately 0.5 volts and the appropriate rear window switch will then command the window in the UP or DOWN direction.

Reference Information

Schematic Reference

Moveable Window Schematics

Connector End View Reference

Window Systems Connector End Views

Power Windows 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

    •  Scan Tool Data List
    •  Scan Tool Output Controls

Circuit/System Verification

Ignition ON, command the each rear window UP and DOWN using the window switches on the driver master control and each rear door window switch. Each rear window should perform the UP and DOWN functions from each switch.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
  2. Test for less than 1.0 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.

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

  6. Test for greater than 10V between the control circuit terminal D and ground.
  7. If less than the specified range, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
  8. Test for greater 10V between the signal circuit terminal C and ground while commanding the rear window DOWN with a scan tool.
  9. If less than the specified range, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
  10. Test for greater 10V between the signal circuit terminal A and ground while commanding the rear window UP with a scan tool.
  11. If less than the specified range, test the control circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
  12. Ignition OFF, connect the rear window switch and disconnect the harness connector at the rear window motor.
  13. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
  14. Ignition ON, command the rear window UP and DOWN by using the rear window switch. The test lamp should turn ON when commanding the UP and DOWN states.
  15. If the test lamp is always OFF during either of the commands, test for a short to ground or open/high resistance on either control circuit. If the circuits test normal, replace the rear window switch.
    If the test lamp is always ON, test for a short to voltage on either control circuit. If the circuits test normal, replace the rear window switch.
  16. If all circuits test normal, test or replace the rear window motor.

Component Testing

  1. Ignition OFF, disconnect the harness connector at the appropriate window motor.
  2. Install a 25A 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 Regulator Motor Replacement
    •  Rear Side Door Window Switch Replacement
    •  Control Module References for BCM replacement, programming, and setup