Power Windows Malfunction (Z75)
Power Windows Malfunction (Z75)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic procedure.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provide an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The front and rear power windows are controlled by the driver door lock/window switch and passenger door lock/window switch. The driver door lock/window switch and passenger door lock/window switch each contain power window switches that are integrated into the module. The driver door lock/window switch contains the master power window switches that control all power window operations. The power window switch contained in the passenger door lock/window switch controls the front passenger window operation only.
When the driver power window switch is activated to a desired position, the driver door lock/window switch examines the request and checks for messages from other vehicle control modules prohibiting window movement. If no prohibitive messages have been received, the driver door lock/window switch will send a serial data message to the driver door window motor to move the window to the desired position.
When the driver door lock/window switch receives a request to operate the right side passenger windows from the master switch, a serial data message is sent to the passenger door lock/window switch. The passenger door lock/window switch examines the request and checks for messages from other vehicle control modules prohibiting the window movement. If no prohibitive messages have been received, the passenger door lock/window switch will send a serial data message to the appropriate window motor to move the window as requested.
When the driver door lock/window switch receives a request to operate a rear window from the master switch, a serial data message is sent to the BCM. The BCM examines the request and checks for messages from other vehicle control modules prohibiting the window movement. If no prohibitive messages have been received, the BCM will send a serial data message to the appropriate rear window switch which will command the window motor as requested.
Reference Information
Schematic Reference
Moveable Window Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Power Windows Description and Operation Power Windows
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON, observe the operation of each power window while commanding the window UP and DOWN by using their local door window switches, each window should perform the UP and DOWN function from each switch.
• If the driver window malfunctions, refer to Front Window Malfunction.
• If the front passenger window malfunctions, refer to Front Window Malfunction.
• If either rear passenger power window malfunctions, refer to Rear Passenger Window Malfunction.
2. Command the left rear window and right rear window UP and DOWN with a scan tool, each rear window should perform the UP and DOWN function.
• If either rear passenger power window malfunctions, refer to Rear Passenger Window Malfunction.
3. Observe the scan tool Driver Window RF Switch, Driver Window LR Switch and Driver Window RR Switch parameters while using the driver master control switches. The parameter should change between Off/Up/Down/Express Down.
• If the value does not change between commanded states, replace the driver door lock/window switch.
4. Observe the scan tool Window Lockout Switch parameter while pressing and depressing the window lockout switch on the driver master control. The parameter should change between On and Off.
• If the value does not change between commanded states, replace the driver door lock/window switch.
5. Command the express up and express down functions of the driver and passenger door windows by pressing their window switches past the first detent and releasing and pulling their window switches past the first detent and releasing. The appropriate window should perform the express up and express down function.
• If the function does not perform as specified, refer to Window Motor Programming - Express Function Testing and Inspection.
Circuit/System Testing
Front Window Malfunction
1. Ignition OFF, disconnect the X1 harness connector at the appropriate door lock/window switch.
2. Test for less than 15 ohms between the ground circuit terminal 6 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit 4 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Ignition OFF, connect the X1 harness connector at the door lock/window switch.
5. Ignition ON, observe the scan tool Driver LF Window Switch parameters while using the driver window switch and the scan tool Passenger Window Switch parameters while using the passenger window switch. The parameters should change between Off, Up, Down, Express Up, and Express Down.
• If the value does not change between commanded states, replace the door lock/window switch.
6. Ignition OFF, disconnect the harness connector at the window motor.
7. Test for less than 15 ohms between the ground circuit terminal 4 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
8. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
9. If all circuits test normal, replace the window motor.
Rear Passenger Window Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
2. Test for less than 10 ohms between the ground circuit terminal F and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal G and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
Note:
Verify the rear windows are enabled by pressing the rear window lockout switch on the driver master control.
4. Test for greater than 9V between the control circuit terminal D and ground.
• 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.
5. Test for greater than 9V between the signal circuit terminal C and ground while commanding the rear window DOWN with a scan tool.
• If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
6. Test for greater than 9V between the signal circuit terminal A and ground while commanding the rear window UP with a scan tool.
• If less than the specified range, test the signal circuit for a short to ground or open/high resistance. If the circuit tests normal, replace the BCM.
7. Ignition OFF, connect the harness connector at rear window switch and disconnect the harness connector at the rear window motor.
8. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
9. Ignition ON, 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.
• If the test lamp is always OFF during either of the commands, test either control circuit for a short to ground or open/high resistance. If the circuits test normal, replace the rear window switch.
• If the test lamp is always ON, test either control circuit for a short to voltage. If the circuits test normal, replace the rear window switch.
10. If all circuits test normal, test or replace the rear window motor.
Component Testing
Rear Window Motor
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 and DOWN functions.
• If it does not perform as specified, replace the window motor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Front Side Door Window Regulator Motor Replacement Service and Repair
* Rear Side Door Window Regulator Motor Replacement Service and Repair
* Rear Side Door Window Switch Replacement Rear Side Door Window Switch Replacement
* Control Module References Control Module References for BCM, driver door lock/window switch or passenger door lock/window switch replacement, setup, and programming