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 driver power window switch contains individual window switches for each of power windows. All windows may be controlled up and down from the driver power window switch. The individual passenger power window switches will only control the up and down operation of their respective power window.
Each power window contains a reversible power window motor. The direction the window travels is dependent upon the polarity of the supply voltage. By reversing polarity of the supply voltage the window motor will move up or down. Each power window motor is internally circuit breaker protected.
Battery voltage is supplied to the power window switch through the accessory voltage supply circuit. The power window switch also receives a constant ground source. The power window motor control circuits are connected to ground through the normally closed up and down contacts of the power window switch. When the power switch is placed in the down position, the power window motor down control circuit is switched to 12 volts and is applied to the down side of the power window motor. Since the other side of the power motor is connected to ground through the normally closed contacts of the up switch, 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
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)
Circuit/System Verification
1. Ignition ON, command the driver window UP and DOWN using the S79D window switch-driver. The driver window should perform the UP and DOWN functions.
• If the driver window does not perform the UP or DOWN function, refer to Driver Window Malfunction.
2. Command each passenger and rear window UP and DOWN using the appropriate switches on the S79D window switch-driver and by using the 79P window switch-passenger, S79LR window switch-left rear and S79RR window switch-right rear. Each window should perform the UP and DOWN functions from each switch.
• If the passenger window does not perform as specified, refer to Front Passenger Window Malfunction.
• If either rear window does not perform as specified, refer to Rear Window Malfunction
3. Disable and enable the rear S79 window switch by pressing and depressing the lockout switch on the S79D window switch-driver. The S79LR window switch-left rear and S79RR window switch-right rear should be enabled and disabled when changing between the commanded states.
• If the S79LR window switch-left rear and S79RR window switch-right rear continue to function while disabled, refer to Lockout Switch Malfunction.
Circuit/System Testing
Driver Window Malfunction
1. Ignition OFF, disconnect the 12 harness connector at the S79D window switch-driver.
2. Test for less than 10 ohm between the ground circuit terminal B 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 ignition circuit terminal E and ground.
• If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
4. Ignition OFF, connect the X1 harness connector at the S79D window switch-driver and disconnect the harness connector at the M74D window motor-driver.
5. Test for less than 10 ohm between the control circuit terminal A and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S79D window switch-driver.
6. Test for less than 10 ohm between the control circuit terminal B and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S79D window switch-driver.
7. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
8. Ignition ON, command the driver door window UP and DOWN by using the driver window switch. The test lamp should illuminate when commanding the UP and DOWN states.
• If the test lamp remains OFF during either of the commands, test either control circuit for a short to ground. If the circuits test normal, replace the S79D window switch-driver.
9. If all circuits test normal, test or replace the M74D window motor-driver.
Front Passenger Window Malfunction
1. Ignition OFF, disconnect the harness connector at the S79P window switch passenger.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal A and ground.
• If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.
3. Ignition OFF, test for less than 10 ohm between the control circuit terminal H and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the S79D window switch-driver.
4. Test for less than 10 ohm between the signal circuit terminal D and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the S79D window switch-driver.
5. Connect a test lamp between the signal circuit terminal D and signal circuit terminal H.
6. Ignition ON, command the passenger window UP and DOWN by using the right front switch on the S79D window switch-driver. The test lamp should illuminate during the UP and DOWN commands.
• If the test lamp does not illuminate during the UP or DOWN command, test either control circuit for a short to ground. If the circuits test normal, test or replace the S79D window switch-driver.
7. Ignition OFF, connect the harness connector at the S79P window switch passenger. Disconnect the harness connector at the M74P window motor-passenger.
8. Test for less than 10 ohm between the control circuit terminal A and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S79P window switch passenger.
9. Test for less than 10 ohm between the control circuit terminal B and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the S79P window switch passenger.
10. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
11. Ignition ON, command the M74P window motor-passenger UP and DOWN by using the S79P window switch passenger. The test lamp should illuminate when commanding the UP and DOWN states.
• If the test lamp does not illuminate during the UP or DOWN command, test either control circuit for a short to ground. If the circuits test normal, test or replace the S79P window switch passenger.
12. If all circuits test normal, test or replace the passenger window motor.
Rear Window Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate rear S79 window switch.
Note: Verify the rear windows are enabled by checking the window lockout switch on the S79D window switch-driver.
2. Ignition ON, verify that a test lamp illuminates between the control circuit terminal E and ground.
• If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the S79D window switch-driver.
3. Ignition OFF, test for less than 10 ohm between the signal circuit terminal C and ground.
• If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the S79D window switch-driver.
4. Test for less than 10 ohm between the signal circuit terminal H and ground.
• If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the S79D window switch-driver.
5. Connect a test lamp between the signal circuit terminal C and signal circuit terminal H.
6. Ignition ON, command the rear window UP and DOWN using the window switch on the driver master control. The test lamp should illuminate when commanding the UP and DOWN states.
• If the test lamp does not illuminate during either of the commands, test both signal circuits for a short to ground. If the circuits test normal, test or replace the S79D window switch-driver.
7. Ignition OFF, connect the harness connector at the rear S79 window switch and disconnect the harness connector at the rear M74 window motor.
8. Test for less than 10 ohm between the control circuit terminal A and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the rear S79 window switch.
9. Test for less than 10 ohm between the control circuit terminal B and ground.
• If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the rear S79 window switch.
10. Connect a test lamp between the control circuit terminal A and control circuit terminal B.
11. Ignition ON, command the rear window UP and DOWN using the rear window switch. The test lamp should illuminate when commanding the UP and DOWN states.
• If the test lamp does not illuminate during either of the commands, test both control circuits for a short to ground. If the circuits test normal, test or replace the rear S79 window switch.
12. If all circuits test normal, test or replace the rear M74 window motor.
Lockout Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate rear S79 window switch.
2. Connect a test lamp between the control circuit terminal E and ground.
3. Ignition ON, command the rear window lockout ON and OFF by pressing and depressing the lockout switch on the S79D window switch-driver. The test lamp should turn ON and OFF when changing between the commanded states.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, test or replace the S79D window switch-driver.
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the S79D window switch-driver
4. If all circuits test normal, test or replace the rear S79 window switch.
Component Testing
Driver Window Switch
1. Ignition OFF, disconnect theX1 and X2 harness connectors at the driver window switch.
2. Test for less than 2 ohm between the lockout control terminal F and the B+ terminal E with the lockout switch in the ENABLE position.
• If greater than the specified value, replace the driver window switch.
3. Test for infinite resistance between the lockout control terminal F and the B+ terminal E with the lockout switch in the DISABLE position.
• If less than the specified value, replace the driver window switch.
4. With the switch in the INACTIVE position, test for infinite resistance between the appropriate signal and control terminals and the ignition terminal E listed below:
* Control terminal A
* Signal terminal B
* Signal terminal C
* Signal terminal D
* Control terminal E
* Signal terminal G
* Signal terminal H
• If less than the specified value, replace the driver window switch.
5. With the switch in the UP position, test for less than 2 ohm between the control terminals and the ignition terminal E listed below:
* Signal terminal D
* Signal terminal G
* Signal terminal B
* Control terminal E
• If greater than the specified range, replace the driver window switch.
6. With the switch in the DOWN position, test for less than 2 ohm between the control terminals and the ignition terminal E listed below:
* Signal terminal C
* Signal terminal H
* Signal terminal C
* Control terminal A
• If greater than the specified range, replace the driver window switch.
Front Passenger Window Switch
1. Ignition OFF, disconnect the harness connector at the passenger window switch.
2. Test for infinite resistance between the control terminals G and F and the ignition terminal A with the switch in the INACTIVE position.
• If less than the specified value, replace the passenger window switch.
3. Test for less than 2 ohm between the control terminal G and the B+ terminal A with the switch in the UP position.
• If greater than the specified range, replace the passenger window switch.
4. Test for less than 2 ohm between the control terminal F and the ignition terminal A with the switch in the DOWN position.
• If greater than the specified range, replace the passenger window switch.
Rear Window Switch
1. Ignition OFF, disconnect the harness connector at the appropriate rear window switch.
2. Test for infinite resistance between the control terminals D and A and the control terminal E with the switch in the INACTIVE position.
• If less than the specified value, replace the rear window switch.
3. Test for less than 2 ohm between the control terminal D and the control terminal E with the switch in the UP position.
• If greater than the specified range, replace the rear window switch.
4. Test for less than 2 ohm between the control terminal A and the control terminal E with the switch in the DOWN position.
• If greater than the specified range, replace the rear window switch.
Rear Window Motor
1. Ignition OFF, disconnect the harness connector at the appropriate M74 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 M74 window motor should perform the UP and DOWN functions.
• If it does not perform as specified, replace the M74 window motor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Front Side Door Window Switch Replacement (Impala) (Front Side Door Window Switch Replacement)
* Front Side Door Window Regulator Motor Replacement (Front Side Door Window Regulator Motor Replacement)
* Rear Side Door Window Regulator Motor Replacement (Rear Side Door Window Regulator Motor Replacement)
* Rear Side Door Window Switch Replacement (Rear Side Door Window Switch Replacement)