The vehicle is equipped with power windows controlled by the door modules. If the driver door module (DDM) receives a window switch request from one of the window switches built into the driver door switch assembly (DDSA), the DDM checks the Class 2 serial data to see if the status information is correct (i.e. ignition switch position) to permit window operation to occur. If the status information is correct, the DDM, either supplies power and ground to its associated window motor, or sends a command via the power door serial data line to the passenger door module controlling the window. The passenger door module controlling the window then supplies power and ground to its associated window motor to move the window as requested.

When one of the local window switches mounted on one of the passenger doors is operated, the associated door module examines the request and checks to see if there are any messages from the DDM prohibiting the movement. If conditions are correct, and no prohibitive messages have been received from the DDM, the associated door module then supplies power and ground to its associated window motor to move the window as requested.

Each door module has its own separate battery positive voltage supply circuit for power window operation, but they are all fed by the same 30 amp power window circuit breaker located in the rear fuse block. Each door module also has a separate ground circuit for its power window operation. These circuits are in the same dedicated connector as the window motor drive circuits of each door module.

Each door module supplies battery positive voltage and ground, through the window motor drive circuits, to its associated window motor. The window motors are reversible. The direction the window moves depends on which motor drive circuit the battery positive voltage is applied to, and which motor drive circuit the ground is applied to. To move the window in one direction, the module applies battery positive voltage to one of the motor drive circuits, and ground to the other motor drive circuit. When a window movement in the opposite direction is needed, the module reverses the polarity and supplies power and ground to the opposite circuits to move the window in the reverse direction.

The driver door module (DDM) and the passenger front door module (PDM) have the Express Up feature. This allows the front door windows to be closed without holding the switch to the Up position for the entire window Up cycle. Each of the front door window motors has a window sensor mounted to it. The window sensors detect differences in their respective window motors electrical pulses to determine if there is an obstruction to the travel of its window glass. If one of the sensors detects that a passenger, or other obstacle, has become trapped between the window and window frame, it sends this information, via two communication circuits, to its associated door module. The door module then takes the appropriate action and, either disables the Express Up function, or reverses the direction of window travel.

Each front door module and the corresponding sensor are wired to each other by four separate circuits in order to control the Express Up function. Each front door module supplies battery positive voltage (B+), via the window sensor battery positive voltage circuit, and ground, via the window sensor low reference circuit, to the sensor. Each door module communicates with its sensor via the other two separate and unique communication circuits. The communication circuits are, the window sensor high speed communications circuit, which is a one-way communications line from the sensor to the module, and, the window sensor normal speed communications circuit, which is a two-way communications line that carries information both ways, from the sensor to the module, and, from the module to the sensor. These communication lines are used for state-of-health messages, window switch command status, and, to communicate the actual position of the window glass in relationship to the distance traveled by the window.

If a front door module looses power for any reason, such as a vehicle battery disconnect, the window sensor/motor assembly must be reprogrammed once power has been restored to the door module. Refer to Window Motor Programming - Express Function .

The rear window lockout switch is built into the Driver Door Switch Assembly (DDSA). When it is pressed momentarily, the LED indicator is illuminated, and the DDSA receives the switch signal. The DDSA sends a message over the power door serial data line to the driver door module indicating that the switch is active. The driver door module then sends a message over the power door serial data line to both rear door modules prohibiting the rear windows from being operated from the rear door window switches. The rear windows can still be operated from the driver door by using the rear window switches built into the DDSA.