Power Windows Malfunction (Convertible Front Windows)

Power Windows Malfunction (Convertible Front Windows)

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 and passenger 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 or passenger window 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 motor 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 operation of the driver window when 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/Passenger Window Motor Malfunction

• If the window moves UP and DOWN as commanded

3. Verify the operation of the driver window when commanding the window UP and DOWN with the driver window switch.

• 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

Note: Verify that both rear quarter windows are completely closed, the front express up functions will be disabled when the rear quarter windows are open.

4. Verify the operation of the driver window when commanding the window express UP and express DOWN with the driver window switch.

• If the window does not express UP or express DOWN as commanded
Refer to Window Motor Programming - Express Function Testing and Inspection

1. Verify the operation of the driver window when commanding the window express UP and express DOWN with the driver window switch

• If the window does not express UP or express DOWN as commanded
Refer to Circuit/System Testing - Driver Window Switch Malfunction

• If the window express UP and express DOWN as commanded

5. Verify the operation of the passenger window when commanding the Passenger 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/Passenger Window Motor Malfunction

• If the window moves UP and DOWN as commanded

6. Verify the operation of the passenger window when commanding the window UP and DOWN with the passenger window switch.

• If the window does not move UP and DOWN as commanded
Refer to Circuit/System Testing - Passenger Window Switch Malfunction

• If the window moves UP and DOWN as commanded

Note: Verify that both rear quarter windows are completely closed, the front express up functions will be disabled when the rear quarter windows are open.

7. Verify the operation of the passenger window when commanding the window express UP and express DOWN with the passenger window switch.

• If the window does not express UP or express DOWN as commanded
Refer to Window Motor Programming - Express Function Testing and Inspection

1. Verify the operation of the passenger window when commanding the window express UP and express DOWN with the passenger window switch

• If the window does not express UP or express DOWN as commanded
Refer to Circuit/System Testing - Passenger Window Switch Malfunction

• If the window express UP and express DOWN as commanded

8. All OK.

Circuit/System Testing

Driver/Passenger Window Motor Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate driver or passenger 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 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

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 6 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 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 2 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 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 Window Switch Malfunction

1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the S79P window switch-passenger. 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 scan tool Passenger Window Switch at Door parameter is Inactive.

• If the value is UP

1. Ignition OFF, disconnect the harness connector at the M74P window motor-passenger.

2. Test for infinite resistance between the signal circuit terminal 8 and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the M74P window motor-passenger.

• If the value is Down

1. Ignition OFF, disconnect the harness connector at the M74P window motor-passenger.

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 M74P window motor-passenger.

• If Inactive

5. Install a 3 A fused jumper wire between the signal circuit terminal 7 and the ground circuit terminal 1.

6. Verify the scan tool Passenger Window Switch at Door parameter is Down

• If Inactive

1. Ignition OFF, disconnect the harness connector at the M74P window motor-passenger, 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 M74P window motor-passenger.

• If Down

7. Install a 3 A fused jumper wire between the signal circuit terminal 8 and ground circuit terminal 1.

8. Verify the scan tool Passenger Window Switch at Door parameter is Up

• If Inactive

1. Ignition OFF, disconnect the harness connector at the M74P window motor-passenger, ignition ON.

2. Test for less than 1 V between the signal circuit terminal 8 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 M74P window motor-passenger.

• If Down

9. Test for greater than 10 V between the signal circuit terminal 6 and ground circuit terminal 1.

• If less than 10 V

1. Ignition OFF, disconnect the harness connector at the M74P window motor-passenger.

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 M74P window motor-passenger.

• If greater than 10 V

10. Test or replace the S79P window switch-passenger.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

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