Circuit/System Description
The HVAC control module monitors the voltage level on the supply voltage circuit of the REAR DEFOG relay. The voltage level should be low while the REAR DEFOG relay is de-energized. The voltage will be near system voltage when the HVAC control module energizes the REAR DEFOG relay.
The front door power window motors communicate with the driver door module (DDM) and passenger door module (PDM) via serial data. The motors contain a logic module which must be normalized or programmed any time the window motor is serviced to provide proper operation and communication between door modules and window motors.
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) monitors the window UP/DOWN command from the driver door switch (DDS). When the rear window UP or DOWN command is received, the BCM sends a signal to the appropriate rear window switch. The rear window switches continuously monitor the up and down signal circuits, if no function is being commanded, the signal voltage is at approximately B+ voltage. If the UP or DOWN function is commanded, the BCM signal voltage drops approximately 0.5 volts and the appropriate rear window switch will then command the window in the UP or DOWN direction.
The body control module (BCM) monitors the window lockout command from the driver door switch (DDS). When the rear window switch operation is authorized, the the BCM signal voltage drops approximately 5 volts to the rear window switches allowing for normal window operation from the rear switches. If the rear window lockout function is commanded, the BCM signal voltage is at B+ voltage which disables the rear window switches and the rear windows will only operate when the BCM receives a command from the driver master control.
When the rear defogger button is pressed, voltage is supplied to the relay coil by the HVAC control module which also illuminates the rear window defogger indicator. B+ voltage is supplied at all times to the relay switched input and the 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 front and rear power windows are controlled by the driver door lock/window switch and passenger door lock/window switch. The driver door lock/window switch and passenger door lock/window switch each contain power window switches that are integrated into the module. The driver door lock/window switch contains the master power window switches that control all power window operations. The power window switch contained in the passenger door lock/window switch controls the front passenger window operation only.
When the driver power window switch is activated to a desired position, the driver door lock/window switch examines the request and checks for messages from other vehicle control modules prohibiting window movement. If no prohibitive messages have been received, the driver door lock/window switch will send a serial data message to the driver door window motor to move the window to the desired position.
When the driver door lock/window switch receives a request to operate the right side passenger windows from the master switch, a serial data message is sent to the passenger door lock/window switch. The passenger door lock/window switch examines the request and checks for messages from other vehicle control modules prohibiting the window movement. If no prohibitive messages have been received, the passenger door lock/window switch will send a serial data message to the appropriate window motor to move the window as requested.
When the driver door lock/window switch receives a request to operate a rear window from the master switch, a serial data message is sent to the BCM. The BCM examines the request and checks for messages from other vehicle control modules prohibiting the window movement. If no prohibitive messages have been received, the BCM will send a serial data message to the appropriate rear window switch which will command the window motor as requested.
The driver and passenger door lock and side window switches are integrated control module switch assemblies. The driver door lock/window switch controls the passenger window through a serial data message to the passenger door lock lock/window switch. When a power window switch is activated in the up or down positions the driver door lock/window switch or passenger door lock lock/window switch supplies power and ground to their respective window motor control circuits to drive the window motor in the required direction. The rear passenger power windows can also be operated from the driver door lock/window switch through a serial data message to the BCM. The rear passenger window switches on the driver door lock/window switch have 2 positions, up and down, their position is a direct input into the driver door lock/window switch. When the BCM receives a command to operate a rear window up or down, the appropriate signal is sent to the rear door window switch which will command the window motor to perform the up or down function.
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.
The liftglass release switch is an input to the body control module (BCM). The BCM supplies battery voltage to the signal circuit and when the release switch is activated the signal circuit voltage goes low. The BCM controls the liftglass release actuator through the rear wiper motor control module. When the release switch signal is activated, the BCM applies battery voltage as a signal through the liftglass latch release control circuit to the rear wiper motor control module. The rear wiper motor control module supplies voltage to the release actuator through the liftglass latch assembly.
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 driver door switch (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 body control module (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/retained accessory power (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 driver door switch (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
NOTE: 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 driver door switch (DDS) through a GMLAN message to the body control module (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/retained accessory power (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.
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.
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.
Urethane Adhesive Description
For replacement of any adhesive-installed window, use the full cut method only.
Use adhesive systems which meet GM Specification GM 3651G.
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.