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

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Driver Power Window Switch Ignition

1

2

--

--

Passenger Power Window Switch Ignition

1

3

--

--

Driver Power Window Motor Control

2

2

2

--

Passenger Power Window Motor Control

3

3

3

--

Passenger Power Window Master Switch Up Control

3

3

--

--

Passenger Power Window Master Switch Down Control

3

3

--

--

Driver Power Window Switch Ground

--

1

1

--

Passenger Power Window Switch Ground

--

1

1

--

1. Power Windows Inoperative - All

2. Power Window Inoperative - Driver

3. Power Window Inoperative - Passenger

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

Power Window Schematics

Connector End View Reference

Power Door Systems Connector End Views

Electrical Information Reference

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

Scan Tool Reference

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Testing

  1. Ignition OFF, disconnect the passenger power window switch.
  2. Ignition ON, verify that a test lamp illuminates between the ignition circuit and ground.
  3. If the test lamp does not illuminate, repair the ignition circuit for an open/high resistance. If the circuit tests normal, replace the BCM.
  4. Connect a test lamp between the power window master switch up and down control circuits at the passenger power window switch harness connector.
  5. Activate the driver power window switch that controls the passenger window to the up and down positions. The test lamp should illuminate as the driver power window switch is activated to the up and down positions.
  6. If the test lamp does not illuminate, repair the power window master switch up and down signal circuits for an open/high resistance. If the circuits test normal, test or replace the driver power window switch.
  7. Ignition OFF, reconnect the passenger power window switch.
  8. Disconnect the passenger power window motor.
  9. Connect a test lamp between the passenger power window motor up and down control circuits at the passenger power window motor harness connector.
  10. Ignition ON, activate the passenger power window switch to the up and down positions. The test lamp should illuminate as the passenger power window switch is cycled between up and down.
  11. If the test lamp does not illuminate, repair the passenger power window motor up and down control circuits for an open/high resistance. If the circuits test normal, test or replace the passenger power window switch.
  12. If all circuits test normal, test or replace the passenger power window motor.

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.