Vauxhall Workshop Service and Repair Manuals

Power Windows Malfunction - AEF/AER/AXG

Diagnostic Instructions

Diagnostic Fault Information

Circuit/System Description

When a window switch is pressed on the driver window switch, 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 prohibiting the 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 switch which will perform the command as requested.

Each power window motor is controlled by their respective window switches. When a power window switch is activated to a desired position, power window switch will send a signal to its respective door window motor to move the window to the desired position.

Diagnostic Aids

The loss of the express up and express down functions for the driver, passenger, left rear or right rear window may have occurred for the following reasons:

The window motor will need to be normalised in order to restore the express functions, refer to Window Regulator Motor Programming and Setup for the proper procedure

Reference Information

Schematic Reference

Moveable Window Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Windows Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

1. Ignition ON, command each M74 window motor UP, DOWN, express UP and express DOWN with a scan tool. Each window should perform the UP, DOWN, express UP and express DOWN commands.

⇒	If a window does perform as specified, refer to Window Motor Malfunction.

2. Command the M74D window motor--driver UP, DOWN, express UP and express DOWN by using the S79D window switch-driver. The M74D window motor--driver should perform the UP, DOWN, express UP and express DOWN commands.

⇒	If the M74D window motor--driver does perform as specified, refer to Driver Window Switch Command Malfunction.

3. Observe the scan tool parameters listed below while using each switch on the S79D window switch-driver. The values should change from Inactive to Active as each switch is used.

•	Front Passenger Main Control Down Switch

•	Front Passenger Main Control Express Switch

•	Front Passenger Main Control Up Switch

•	Left Rear Window Main Control Down Switch

•	Left Rear Window Main Control Express Switch

•	Left Rear Window Main Control Up Switch

•	Right Rear Window Main Control Down Switch

•	Right Rear Window Main Control Express Switch

•	Right Rear Window Main Control Up Switch

•	Window Lockout Switch

⇒	If any of the values are always Inactive or always Active, refer to Driver Switches Malfunction.

4. Command the M74P window motor--passenger UP, DOWN, express UP and express DOWN by using the S79P window switch-passenger. The M74P window motor--passenger should perform the UP, DOWN, express UP and express DOWN commands

⇒	If the M74P window motor--passenger does perform as specified, refer to Passenger/Rear Window Malfunction.

5. Command the M74LR window motor--left rear UP, DOWN, express UP and express DOWN by using the S74LR rear window switch--left rear. The M74LR window motor--left rear should perform the UP, DOWN, express UP and express DOWN functions.

⇒	If the M74LR window motor--left rear does perform as specified, refer to Passenger/Rear Window Malfunction.

6. Command the M74RR window motor--right rear UP, DOWN, express UP and express DOWN by using the S74RR rear window switch--right rear. The M74RR window motor--right rear should perform the UP, DOWN, express UP and express DOWN functions.

Circuit/System Testing

Window Motor Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate M74 window motor.
2. After 10 minutes, test for less than 10 Ω 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 Command Malfunction

1. Ignition OFF, disconnect the harness connector at the S79D window switch-driver.
2. Test for less than 5 Ω 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 specifed value, test the control circuit terminal 3 for a short to ground. If the circuit tests normal, test or replace the M74D window motor-driver.

4. Connect a 5A fused jumper wire between the control 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 control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the M74D window motor-driver.

5. Verify that the scan tool Driver Window Main Control Up Switch parameter is Inactive.

⇒	If not the specifed value, test the control circuit terminal 6 for a short to ground. If the circuit tests normal, test or replace the M74D window motor-driver.

6. Connect a 5A fused jumper wire between the control circuit terminal 6 and ground, verify that the scan tool Driver Window Main Control Up Switch parameter is Active.

⇒	If not the specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the M74D window motor-driver.

7. Verify that the scan tool Driver Window Main Control Express Switch parameter is Inactive.

⇒	If not the specifed value, test the control circuit terminal 2 for a short to ground. If the circuit tests normal, test or replace the M74D window motor-driver.

8. Connect a 5A fused jumper wire between the control circuit terminal 2 and ground, verify that the scan tool Driver Window Main Control Express Switch parameter is Active.

⇒	If not the specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the M74D window motor-driver.

9. If all circuits test normal, test or replace the S79D window switch-driver.

Driver Switches Malfunction

1. Ignition OFF, disconnect the harness connector at the S79D window switch-driver.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 4 and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or and open/high resistance.

3. Test for 5 - 10 V between the serial data circuit terminal 5 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.

4. If all circuit test normal, replace the S79D window switch-driver.

Passenger/Rear Window Malfunction

1. Ignition OFF, disconnect the harness connector at the appropriate M74 window motor.
2. Test for less than 5 Ω 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. Ignition OFF, connect the harness connector at the M74 window motor and disconnect the harness connector at the appropriate S79 window switch.
6. Test for less than 25 Ω between the ground circuit terminal 1 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

7. Ignition ON, verify that the scan tool Window Switch at Door parameter is Inactive.

⇒	If the value is Up, test the control circuit terminal 8 for a short to ground. If the circuit tests normal, test or replace the M74 window motor.

⇒	If the parameter is Down, test the control circuit terminal 7 for a short to ground. If the circuit tests normal, test or replace the M74 window motor.

⇒	If the parameter is Express, test the control circuit terminal 6 for a short to ground. If the circuit tests normal, test or replace the M74 window motor.

8. Connect a 5A fused jumper wire between the control circuit terminal 6 and ground, verify that the scan tool Window Switch at Door parameter is Express.

⇒	If not the specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the M74 window motor.

9. Connect a 5A fused jumper wire between the control circuit terminal 7 and ground, verify that the scan tool Window Switch at Door parameter is Down.

⇒	If not the specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the M74 window motor.

10. Connect a 5A fused jumper wire between the control circuit terminal 8 and ground, verify that the scan tool Window Switch at Door parameter is Up.

⇒	If not the specified value, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, test or replace the M74 window motor.

11. If all circuits test normal, test or replace the S79 window switch.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.