Power Windows Malfunction (Convertible Rear Windows)
Power Windows Malfunction (Convertible Rear 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 front power windows can be controlled by the driver window switch. The driver window switch contains window switches that control all power window operations. When a power window switch is activated to a desired position, power window switch will send a serial data message to the body control module (BCM) which will send the command to the appropriate window motor to move the window to the desired position. The window motors will also receive a signal from the BCM to globally express down while lowering the convertible top.
Diagnostic Aids
The loss of the express up and express down functions for the driver, passenger and rear windows 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 or replaced
The window motors 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 scan tool Left Rear Main Control Down Switch, Left Rear Main Control Express Switch, Left Rear Main Control Up Switch, Right Rear Main Control Down Switch, Right Rear Main Control Express Switch and Right Rear Main Control Up Switch parameter changes between Inactive and Active when pressing and pulling appropriate switches on the driver window switch.
• If any parameter does not change
Refer to Circuit/System Testing - Driver Window Switch Malfunction.
• If all the parameters change
3. Verify the left rear and right rear window moves while commanding the window UP and DOWN with a scan tool.
• If a rear window does not move UP and DOWN as commanded
Refer to Circuit/System Testing - Rear Power Window Inoperative.
• If the rear window moves UP and DOWN as commanded
4. All OK.
Circuit/System Testing
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. 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
3. 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, replace the S79D window switch-driver
• If the test lamp illuminates
4. 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 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
5. Test or replace the S79D window switch-driver.
Rear Power Window Inoperative
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the appropriate rear 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
3. 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, replace the rear 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 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. Replace the rear M74 window motor.
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
* Quarter Window Regulator Motor Replacement Service and Repair
* Control Module References Control Module References for the BCM replacement, programming and setup