Power Windows Malfunction (Coupe Front Windows)
Power Windows Malfunction (Coupe 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 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
A window motor that has not been normalized will no longer perform the express up and express down functions, this may occur during the following conditions:
* When a window motor has been disconnected
* When a door harness has been disconnected
* When the battery has been disconnected or replaced
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
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 moves 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/Passenger 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 driver window switch.
• If the window does not move UP and DOWN as commanded
Refer to Circuit/System Testing - Driver Window Malfunction From Driver Window Switch.
• If the window moves UP and DOWN as commanded
4. Verify the driver window performs the express UP and express DOWN functions with the driver window switch.
• If the driver window does not express UP or express DOWN
1. Normalize the driver window motor, refer to Window Motor Programming - Express Function Testing and Inspection.
2. Verify the driver window performs the express UP and express DOWN functions.
• If the driver window does not express UP or DOWN, refer to Circuit/System Testing - Driver Window Malfunction From Driver Window Switch.
• If the driver window performs the express UP and express DOWN functions
5. Verify the passenger window moves while commanding the Passenger Window Motor Up and Down with a scan tool.
• If the passenger 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 passenger window moves while commanding the window UP and DOWN with the driver window switch and passenger window switch.
• If the passenger window does not move UP and DOWN as commanded from the passenger window switch only
Refer to Circuit/System Testing - Passenger Window Switch Inoperative.
• If the passenger window does not move UP and DOWN as commanded from either window switch
Refer to Circuit/System Testing - Passenger Window Malfunction From Both Switches.
• If the window moves UP and DOWN as commanded from both switches
7. Verify the passenger performs the express UP and express DOWN functions with the passenger window switch.
• If the passenger window does not express UP or express DOWN
1. Normalize the passenger window motor, refer to Window Motor Programming - Express Function Testing and Inspection.
2. Verify the passenger window performs the express UP and express DOWN functions.
• If the passenger window does not express UP or DOWN, refer to Circuit/System Testing - Passenger Window Malfunction From Both Switches.
• If the passenger window performs the express UP and express DOWN functions.
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 Malfunction From Driver Window Switch
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 Inoperative
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. Test or replace the S79P window switch-passenger.
Passenger Window Malfunction From Both Switches
1. Ignition OFF, disconnect the harness connector at the S79P window switch-passenger.
2. Disconnect the harness connector at the S79D window switch-driver, ignition ON.
3. 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
4. Install a 3 A fused jumper wire between the signal circuit terminal 7 and the ground circuit terminal 1.
5. 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
6. Install a 3 A fused jumper wire between the signal circuit terminal 8 and ground circuit terminal 1.
7. 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
8. 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
9. Ignition OFF, connect the harness connector at the S79P window switch - passenger. Ignition ON
10. Verify the scan tool Passenger Window Switch at Door parameter changes between Inactive and Up, Express Up, Down, and Express Down when pressing and pulling the S79P window switch-passenger.
• If any parameter does not change
Test or replace the S79P window switch-passenger.
• If all the parameters change
11. Ignition OFF, connect the harness connector at the S79D window switch - driver. Ignition ON
12. Verify the scan tool Passenger Window Switch at Door parameter changes between Inactive and Up, Express Up, Down, and Express Down when pressing and pulling the appropriate switch on the S79D window switch-driver.
• If any parameter does not change
Test or replace the S79D window switch-driver.
• If all the parameters change
13. Test or replace the M74P window motor-passenger.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Front Side Door Window Switch Replacement Front Side Door Window Switch Replacement
* Front Side Door Window Regulator Motor Replacement Service and Repair
* Control Module References Control Module References for BCM replacement, programming and setup