Power Windows Malfunction
Power Windows Malfunction
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 approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The window motors supply 12V signal circuits to their respective window switches, when a window switch has been activated, a switch closes providing a ground to the appropriate signal circuit causing the voltage to drop to 0V. The window motor will detect the voltage drop in the signal circuit and will command the window to move in the desired direction.
The driver window master control switch also contains control switches for the passenger, left rear and right rear window functions. When a window switch is pressed, a serial data message is sent to the Body Control Module (BCM). The BCM examines the request and checks for messages from other power window motors that may prohibit window movement. If no prohibitive messages have been received, the BCM will send a serial data message to the passenger window motor or to the appropriate rear window motor which will perform the command as requested.
Diagnostic Aids
The loss of the express up and express down functions for the driver, passenger and rear windows may have occurred for the following reasons:
* The battery was disconnected
* The battery was replaced
* A door wiring harness was disconnected
* A window motor was disconnected
The window motors will need to be normalized in order to restore the express functions, refer to Window Motor Programming - Express Function Testing and Inspection for the proper procedure.
Reference Information
Schematic Reference
Moveable Window Schematics Electrical Diagrams
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
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.
2. Verify the driver window functions while commanding the Driver Window Motor Up and Down with a scan tool.
• If the window does not move Up and Down as commanded
Refer to Circuit/System Testing - Driver Window Motor Malfunction.
• If the window moves Up and Down as commanded
3. Verify the driver window moves while commanding the window UP and DOWN with the S79D Window Switch-Driver.
• If the window does not move UP and DOWN as commanded
Refer to Circuit/System Testing - Driver Window Switch Malfunction.
• If the window moves UP and DOWN as commanded
4. Verify the driver window performs the express UP and express DOWN functions with the S79D Window Switch-Driver.
• If the driver window does not express UP or express DOWN
Normalize the driver window motor, refer to Window Motor Programming - Express Function Testing and Inspection.
1. Verify the driver window performs the express UP and express DOWN functions with the S79D Window Switch-Driver
• If the driver window does not express UP or express DOWN
Refer to Circuit/System Testing - Driver Window Switch Malfunction.
• If the driver window performs the express UP and express DOWN functions
5. Verify the scan tool parameters listed below change when pressing and pulling the switches for the passenger, left rear and right rear window on the driver window master control;
* Left Rear Main Control Down Switch - Inactive and Active
* Left Rear Main Control Express Switch - Inactive and Active
* Left Rear Main Control Up Switch - Inactive and Active
* Right Rear Main Control Down Switch - Inactive and Active
* Right Rear Main Control Express Switch - Inactive and Active
* Right Rear Main Control Up Switch - Inactive and Active
* Front Passenger Main Control Down Switch - Inactive and Active
* Front Passenger Main Control Express Switch - Inactive and Active
* Front Passenger Main Control Up Switch - Inactive and Active
• If any parameter does not change
Replace the S79D Window Switch-Driver.
• If the parameters change
6. Verify the scan tool Child Security Lockout Switch parameter changes between Inactive and Active when pressing the window lockout switch.
• If the parameters do not change
Refer to Power Door Child Lock Malfunction Power Door Child Lock Malfunction
• If the parameters changes
7. Verify the lockout indicator turns ON and OFF when commanding the Child Security Lock Indicator ON and OFF with a scan tool.
• If the indicator does not turn ON and OFF
Replace the S79D Window Switch-Driver.
• If the indicator turns ON and OFF
8. Verify the passenger, left rear and right rear window move while commanding the Passenger Window Motor, Left Rear Window Motor, and Right Rear Window Motor Up and Down with a scan tool.
• If the window does not move Up and Down as commanded
Refer to Circuit/System Testing - Window Motor Malfunction.
• If the window moves Up and Down as commanded
9. Verify the passenger and rear window moves while commanding the window UP and DOWN with the appropriate passenger or rear S79 Window Switch.
• If a window does not move UP and DOWN as commanded
Refer to Circuit/System Testing - Passenger/Rear Window Switch Malfunction.
• If the window moves UP and DOWN as commanded
10. Verify the passenger and rear windows perform the express UP and express DOWN functions with the respective passenger or rear S79 Window Switch.
• If a window does not express UP or express DOWN
Normalize the window motor, refer to Window Motor Programming - Express Function Testing and Inspection.
1. Verify the window performs the express UP and express DOWN functions with the S79 Window Switch
• If a window does not express UP or express DOWN
Refer to Circuit/System Testing - Passenger/Rear Window Switch Malfunction.
• If the window performs the express UP and express DOWN functions
11. Command the rear window lockout by pressing the window lockout switch on the S79D Window Switch-Driver.
12. Verify the left rear and right rear window does not move while commanding the window UP and DOWN with the S79LR Window Switch-Left Rear and S79RR Window Switch-Right Rear.
• If a rear window moves UP and DOWN as commanded
Refer to Power Door Child Lock Malfunction Power Door Child Lock Malfunction.
• If the rear windows do not move UP and DOWN
13. All OK.
Circuit/System Testing
Window Motor Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate M74 Window Motor. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal 2 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the M74 window motor.
• If the test lamp illuminates
5. Test for 5-10 V between the serial data circuit terminal 4 and ground
• If less than 5 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the serial data circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the serial data circuit end to end.
• If 2 ohms or greater, repair the open/high resistance on the circuit.
• If less than 2 ohms, replace the K9 Body Control Module.
• If greater than 10 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the serial data circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 Body Control Module.
• If between 5-10 V
6. Test or replace the M74 Window Motor.
Driver Window Switch Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S79D Window Switch-Driver. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the B+ circuit terminal 4 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the S79D Window Switch-Driver.
• If the test lamp illuminates
5. Test for 5-10 V between the serial data circuit terminal 5 and ground
• If less than 5 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the serial data circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the serial data circuit end to end.
• If 2 ohms or greater, repair the open/high resistance on the circuit.
• If less than 2 ohms, replace the K9 Body Control Module.
• If greater than 10 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, ignition ON.
2. Test for less than 1 V between the serial data signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 Body Control Module.
• If between 5-10 V
6. Verify the scan tool Driver Window Main Control Down Switch parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver.
2. Test for infinite resistance between the signal circuit terminal 7 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the M74D Window Motor-Driver.
• If Inactive
7. Install a 3 A fused jumper wire between the signal circuit terminal 3 and the ground circuit terminal 1.
8. Verify the scan tool Driver Window Main Control Down Switch parameter is Active
• If not Active
1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.
2. Test for less than 1 V between the signal circuit terminal 7 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the M74D Window Motor-Driver.
• If Active
9. Verify the scan tool Driver Window Main Control Up Switch parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver.
2. Test for infinite resistance between the signal circuit terminal 3 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the M74D Window Motor-Driver.
• If Inactive
10. Install a 3 A fused jumper wire between the signal circuit terminal 6 and the ground circuit terminal 1.
11. Verify the scan tool Driver Window Main Control Up Switch parameter is Active
• If not Active
1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.
2. Test for less than 1 V between the signal circuit 3 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the M74D Window Motor-Driver.
• If Active
12. Verify the scan tool Driver Window Main Control Express Switch parameter is Inactive.
• If not Inactive
1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver.
2. Test for infinite resistance between the signal circuit terminal 5 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the M74D Window Motor-Driver.
• If Inactive
13. Install a 3 A fused jumper wire between the signal circuit terminal 2 and the ground circuit terminal 1.
14. Verify the scan tool Driver Window Main Control Express Switch parameter is Active
• If not Active
1. Ignition OFF, disconnect the harness connector at the M74D Window Motor-Driver, ignition ON.
2. Test for less than 1 V between the signal circuit 5 and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the M74D Window Motor-Driver.
• If Active
15. Test or replace the S79D Window Switch-Driver.
Passenger/Rear Window Switch Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate passenger or rear S79 Window Switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify the appropriate scan tool Window Switch at Door parameter is Inactive.
• If Up
1. Ignition OFF, disconnect the harness connector at the M74 Window Motor.
2. Test for infinite resistance between the signal circuit terminal listed below and ground.
* S79P Window Switch-Passenger - signal circuit terminal 8
* S79LR Window Switch-Left Rear - signal circuit terminal 6
* S79RR Window Switch-Right Rear - signal circuit terminal 6
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the M74 Window Motor.
• If Down
1. Ignition OFF, disconnect the harness connector at the M74 Window Motor, ignition ON.
2. Test for infinite resistance between the signal circuit terminal 7 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the M74 Window Motor.
• If Inactive
5. Install a 3 A fused jumper wire between the circuit terminals listed below:
* S79P Window Switch-Passenger - signal circuit terminal 8 and the ground circuit terminal 1
* S79LR Window Switch-Left Rear - signal circuit terminal 6 and the ground circuit terminal 1
* S79RR Window Switch-Right Rear - signal circuit terminal 6 and the ground circuit terminal 1
6. Verify the scan tool Window Switch at Door parameter is Up
• If Inactive
1. Ignition OFF, disconnect the harness connector at the M74 Window Motor, ignition ON.
2. Test for less than 1 V between the signal circuit terminal and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the M74 Window Motor.
• If Up
7. Install a 3 A fused jumper wire between the signal circuit terminal 7 and the ground circuit terminal 1.
8. Verify the scan tool Window Switch at Door parameter is Down
• If Inactive
1. Ignition OFF, disconnect the harness connector at the M74 Window Motor, ignition ON.
2. Test for less than 1 V between the signal circuit terminal and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the M74 Window Motor.
• If Down
9. Test for greater than 10 V between the signal circuit terminal and the ground circuit terminal listed below:
* S79P Window Switch-Passenger - signal circuit terminal 6 and the ground circuit terminal 1
* S79LR Window Switch-Left Rear - signal circuit terminal 8 and the ground circuit terminal 1
* S79RR Window Switch-Right Rear - signal circuit terminal 8 and the ground circuit terminal 1
• If less than 10 V
1. Ignition OFF, disconnect the harness connector at the M74 Window Motor.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance on the circuit.
• If less than 2 ohms, replace the M74 Window Motor.
• If greater than 10 V
10. Test or replace the passenger or rear S79 Window Switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Front Side Door Window and Multifunction Switch Replacement Front Side Door Window and Multifunction Switch Replacement
* Front Side Door Window Regulator Replacement Service and Repair
* Front Side Door Window Switch Replacement Front Side Door Window Switch Replacement
* 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 replacement, programming and setup