Circuit/System Description
The HVAC control module controls the rear window defroster through the REAR DEFOG relay located in the underhood fuse block. When the rear defroster is activated the HVAC control module supplies battery voltage through the defroster relay control circuit to energize the relay coil.
The driver door switch (DDS) and passenger door switch (PDS) control the power window functions through the power window motor up and down control circuits. The door switches monitor the control circuits for fault conditions when up or down operation is requested prior to activating the function and during operation.
The body control module (BCM) energizes the control side of the left rear power window up relay upon receiving a GMLAN message from the driver door switch (DDS).
The body control module (BCM) energizes the control side of the left rear power window down relay upon receiving a GMLAN message from the driver door switch (DDS).
Accessory/RAP voltage is supplied to the left rear power window switch through the window lockout signal circuit. If the window lockout function is disabled, the body control module (BCM) supplies voltage to the rear window switches allowing for normal window operation from the rear switches. If the window lockout function is enabled, the BCM will not supply voltage to the rear window switches and the rear windows will only operate from the driver power window switch through the BCM up and down signal circuits.
The body control module (BCM) energizes the control side of the right rear power window up relay upon receiving a GMLAN message from the driver door switch (DDS).
The body control module (BCM) energizes the control side of the right rear power window down relay upon receiving a GMLAN message from the driver door switch (DDS).
Accessory/RAP voltage is supplied to the right rear power window switch through the window lockout signal circuit. If the window lockout function is disabled, the body control module (BCM) supplies voltage to the rear window switches allowing for normal window operation from the rear switches. If the window lockout function is enabled, the BCM will not supply voltage to the rear window switches and the rear windows will only operate from the driver power window switch through the BCM up and down signal circuits.
The HVAC control module controls the rear window defroster through the REAR DEFOG relay located in the underhood fuse block. When the rear defroster is activated the HVAC control module supplies battery voltage through the defroster relay control circuit to energize the relay coil.
The power sliding rear window motor is controlled from the rear window open/close switch through open and close relays. The open/close switch is supplied voltage from the body control module (BCM) accessory voltage output circuit. When the switch is pressed in the open or closed position the open or closed relay coil will be supplied accessory voltage and energized through the appropriate relay control circuit. While the open and close relays are in a de-energized state both motor control circuits will be closed to ground. When one of the relays is energized its motor control circuit will be closed to the battery voltage supply circuit and the other motor control circuit will remain grounded through the de-energized relay.
The driver and passenger door lock and side window switches are integrated control module switch assemblies. When a power window switch is activated in the up or down positions the driver door switch (DDS) supplies power and ground to the window motor control circuits to drive the window motor in the required direction. Prior to activating a power window motor the DDS will supply the control circuit with a low current bias voltage in order to determine that a short to ground condition does not exist and during window motor operation the DDS continues to monitor the motor current to verify proper window motor operation.
The power window system will operate any time the ignition is the ACC or RUN position. The power window system will also operate whenever the body control module (BCM) is in retained accessory power (RAP) mode. 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 each 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.
The drivers window switch has express-up and express-down features that allows the window to be raised and lowered completely without holding the switch. Press the front of the switch part way and release it and the drivers window will open a small amount. Press the switch down all the way and release it and the window will go completely down automatically.
Adhesive Service Kit Description
The GM of Canada Adhesive Caulking Kit, P/N 10952983, contains the following items
- Four different primers
- A tube of urethane adhesive with a nozzle
- Four daubers
- Instructions with warnings
Use the urethane adhesive caulking kit for replacement of any urethane adhesive-installed window using the full cut method.
In the United States or Canada, you may use any of the following equivalent urethane adhesive systems which meet GM Specification GM 3651G
- Dow Automotive - Essex 400HV. One part and requires associated primers.
- Dow Automotive - Essex U216. Two part and requires associated primers. Call Dow Automotive at 1-800-453-3779 for more information.
- 3M™ "Fast Cure" Auto Glass Urethane. One part and requires associated primers. Call 3M™ at 1-877-666-2277 for more information.
Use these materials based on specific manufacturer. Do NOT intermix primers or adhesives from one manufacturer to another.
Always follow the system manufacturer's instructions for application, handling, and curing.
Stationary Window Description
Most stationary windows, specifically windshields, are retained to the body with urethane adhesive which adheres the window to the body, increasing structural integrity. The reinstallation of the windows with urethane adhesive requires complete replacement of the urethane adhesive bead, and is known as the full cut method.
Driver Power Window Operation
The switch for the driver power window has 3 positions UP, Down and Express Down and its position is a direct input into the driver door switch (DDS). Upon receiving a request for power window operation (switch activation), the DDS supplies voltage to the power window motor left front up or down circuit and grounds the opposite and the power window motor runs to move the window up or down.
Front Passenger Power Window Operation
The switch for the front passenger power window has 3 positions UP, Down and Express Down, and its position is a direct input into the passenger door switch (PDS). Upon receiving a request for power window operation (switch activation), the PDS supplies voltage to the power window motor right front up or down circuit and grounds the opposite and the power window motor runs to drive the window up or down.
The front passenger power window can also be operated from the DDS. The front passenger window switch on the DDS has 3 positions UP, Down and Express Down and its position is a direct input into the DDS. Upon receiving a request for front passenger power window operation, the DDS transmits a GMLAN message indicating the changed switch position. When the PDS receives this message, the PDS supplies voltage to the power window motor right front up or down circuit and grounds the opposite and the power window motor runs to move the window up or down.
Rear Passenger Power Window Operation
The rear passenger power window switches are supplied battery voltage through 25A circuit breakers in the IP fuse panel. The rear door window switch up and down relays control power and ground to the window motors through the motor control circuits. The rear window switch relays can be energized by the integrated rocker switch or by the BCM through the up and down signal circuits. While a rear window switch is in an inactive state both of the window motor control circuits are grounded through the up and down relays. When an up or down relay is energized the battery supply circuit is closed to the corresponding motor control circuit while the other control circuit remains grounded through the de-energized relay. The BCM supplies the rocker switches with accessory/RAP voltage through the lockout control circuit while the lockout function is inactive. The supply side of all the window up and down relays receive voltage through the battery voltage supply circuit and the LT DOOR or RT DOOR circuit breakers respectively.
The rear passenger power windows can also be operated from the DDS through a GMLAN message to the BCM. The rear passenger window switches on the DDS have 2 positions UP and Down their position is a direct input into the DDS. When the BCM receives a command to operate a rear window up or down the appropriate signal circuit is used to energize the up or down relay in the rear door window switch.
Rear Power Window Lockout Operation
| IMPORTANT | Power window lockout switch disables REAR passenger window switches only and has no effect on the operation of the FRONT passenger window switch. |
The rear window lockout function is operated from the DDS through a GMLAN message to the BCM. When the BCM receives an active lockout command, the rear door power window switches are disabled. The lockout control circuit from the BCM supplies the accessory/RAP voltage to the rear window switches while the lockout function is inactive and removes the supply voltage to activate the function. Once activated, the lockout feature will remain in effect until the ignition switch is cycled or the DDS receives another power window lockout switch activation.
Power Windows Description and Operation (Rear Window)
The power sliding rear window motor is controlled from the rear window open/close switch through open and close relays. The open/close switch is supplied voltage from the body control module (BCM) accessory voltage output circuit. When the switch is pressed in the open or closed position the open or closed relay coil will be supplied accessory voltage and energized through the appropriate relay control circuit. While the open and close relays are in a de-energized state both motor control circuits will be closed to ground. When one of the relays is energized its motor control circuit will be closed to the battery voltage supply circuit and the other motor control circuit will remain grounded through the de-energized relay.
Rear Window Defogger Operation
When you depress the rear defogger switch, voltage is supplied to the DEFOG relay coil and the HVAC control module also illuminates the rear window defogger indicator. Battery positive voltage is supplied at all times to the DEFOG relay switched input and the DEFOG relay coil is always grounded. This allows battery positive voltage from the relay switched input through the switch contacts and out the relay switched output to the rear window defogger. The HVAC module also sends a message to the driver door module (DDM) and passenger door module (PDM) on the GMLAN serial communication circuit to activate the heated mirrors, if equipped.
When you turn ON the ignition and press the rear window defogger switch for the first time, the defogger cycle lasts 10 minutes. Further operation results in 5 minute defogger cycles.