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 are supplied with B+ voltage which is used to power the motor and also used as a reference voltage within the logic circuit. When the driver or passenger window switch is pressed, a switch is closed causing the reference voltage in the appropriate circuit in the window motor to drop, the window motor responds by moving the window in the direction commanded.
Diagnostic Aids
Failure of a window not completely closing or a window auto reversing when completely closed may have been caused by the following conditions:
* When the window glass has been replaced
* When the door has been replaced
* When the window regulator has been replaced
A relearn procedure may be necessary to correct for the above malfunctions, refer to Window Regulator Motor Programming and Setup (Testing and Inspection).
Reference Information
Schematic Reference
Moveable Window Schematics (Electrical Diagrams)
Connector End View Reference
Component Connector End Views (Connector Views)
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 (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Ignition ON, command the driver window UP and DOWN with a scan tool. The driver window should perform the UP, DOWN functions.
• If the driver window does not perform as specified, refer to Window Motor Malfunction.
2. Command the passenger window UP and DOWN with a scan tool. The passenger window should perform the UP, DOWN functions.
• If the passenger window does not perform as specified, refer to Window Motor Malfunction.
3. Command the driver window UP, DOWN, express UP and express DOWN by using the S79D window switch-driver. The driver window should perform the UP, DOWN and express functions.
• If the driver window does not perform as specified, refer to Driver Window Switch Malfunction.
4. Command the passenger window UP, DOWN, express UP and express DOWN by using the passenger window switch and the right front switch on the S79D window switch-driver, the passenger window should perform the UP, DOWN and express functions from each switch.
• If the passenger window does not perform as specified, refer to Passenger Window Switch Malfunction.
Circuit/System Testing
Window Motor Malfunction
1. Ignition OFF for, disconnect the harness connector at the appropriate M74 window motor.
2. After 10 minutes, test for less than 10 ohm between the ground circuit terminal 1 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 2 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
4. Test for 5 - 10 V between the serial data circuit terminal 4 and ground.
• If greater than the specified range, test the serial data circuit for a short to voltage. If the circuit tests normal, replace the K9 BCM.
• If less than the specified range, test the serial data circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 BCM.
5. If all circuits test normal, replace the M74 window motor.
Driver Window Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S79D window switch-driver.
2. After 10 minutes, test for less than 10 ohm between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify that the scan tool Driver Window Main Control Down Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 3 for a short to ground. If the circuit tests normal, replace the M74D window motor-driver.
4. Connect a 3 A fused jumper wire between the signal circuit terminal 3 and ground. Verify that the scan tool Driver Window Main Control Down Switch parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74D window motor-driver.
5. Verify that the scan tool Driver Window Main Control Up Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the M74D window motor-driver.
6. Connect a 3 A fused jumper wire between the signal circuit terminal 5 and ground. Verify that the scan tool Driver Window Main Control Up Switch parameter is Active.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74D window motor-driver.
7. Verify the scan tool Driver Window Main Control Express Switch parameter is Inactive.
• If not the specified value, test the signal circuit terminal 2 for a short to ground. If the circuit tests normal, replace the M74 driver window motor.
8. Connect a 3 A fused jumper wire between the signal circuit terminal 2 and ground, verify the scan tool Driver Window Main Control Express Switch parameter is Active.
• If not the specified value, test the signal circuit terminal for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74 driver window motor.
9. If all circuits test normal, replace the S79D window switch-driver.
Passenger Window Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S79P window switch-passenger.
2. After 10 minutes, test for less than 10 ohm between the ground circuit terminal 1 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
3. Disconnect the harness connector at the S79D window switch-driver.
4. Ignition ON, verify that the scan tool Passenger Window Switch at Door parameter is Inactive.
• If the value is Up, test the signal circuit terminal 8 for a short to ground. If the circuit tests normal, test or replace the M74P window motor-passenger.
• If the value is Down, test the signal circuit terminal 7 for a short to ground. If the circuit tests normal, test or replace the M74P window motor-passenger.
• If the value is Express, test the signal circuit terminal 6 for a short to ground. If the circuit tests normal, test or replace the M74P window motor-passenger.
5. Connect a 3 A fused jumper wire between the signal circuit terminal 8 and ground, verify that the scan tool Passenger Window Switch at Door parameter is Up.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74P window motor-passenger.
6. Connect a 3 A fused jumper wire between the signal circuit terminal 7 and ground, verify that the scan tool Passenger Window Switch at Door parameter is Down.
• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74P window motor-passenger.
7. Connect a 3 A fused jumper wire between the signal circuit terminal 6 and ground, verify that the scan tool Passenger Window Switch at Door parameter is Express.
• If not the specified value, test the signal circuit terminal for a short to voltage or an open/high resistance. If the circuit tests normal, replace the M74 passenger window motor.
8. Ignition OFF, connect the harness connector at the S79D window switch-driver.
9. Ignition ON, observe the scan tool Passenger Window Switch at Door parameter while using the right front switch on the S79D window switch-driver. The parameters should change from Inactive to Up, Down and Express.
• If the values do not change, test or replace the S79D window switch-driver.
10. If all circuits test normal, test or replace the S79P window switch-passenger.
Component Testing
Driver Window Switch
1. Ignition OFF, disconnect the harness connector at the S79D window switch-driver.
2. With the switch in the INACTIVE position, test for infinite resistance between the signal terminals listed below and the ground terminal 1:
* Terminal 2
* Terminal 3
* Terminal 5
* Terminal 6
* Terminal 7
* Terminal 8
• If less than the specified value, replace the S79D window switch-driver.
3. With the switch in the UP position, test for less than 2 ohm between the signal terminal listed below and the ground terminal 1:
* Terminal 5
* Terminal 8
• If greater than the specified range, replace the S79D window switch-driver.
4. With the switch in the DOWN position, test for less than 2 ohms between the signal terminal listed below and the ground terminal 1:
* Terminal 3
* Terminal 7
• If greater than the specified range, replace the S79D window switch-driver.
Passenger Window Switch
1. Ignition OFF, disconnect the harness connector at the S79P window switch-passenger.
2. Test for infinite resistance between the signal terminals 6, 7 and 8 and the ground terminal 1 with the switch in the INACTIVE position.
• If less than the specified value, replace the S79P window switch-passenger
3. Test for less than 2 ohm between the signal terminal 8 and the ground terminal 1 with the switch in the UP position.
• If greater than the specified range, replace the S79P window switch-passenger.
4. Test for less than 2 ohm between the signal terminal 7 and the ground terminal 1 with the switch in the DOWN position.
• If greater than the specified range, replace the S79P window switch-passenger.
5. Test for less than 2 ohm between the signal terminal 6 and the ground terminal 1 with the switch in the EXPRESS DOWN position
• If greater than the specified range, replace the S79P window switch-passenger.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Side Door Window Switch Replacement (Front Side Door Window Switch Replacement)
* Front Side Door Window Regulator Motor Replacement (Front Side Door Window Regulator Motor Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming