The power window master switch left front up or down signal circuits provide inputs to the driver door module (DDM) when the driver window switch is activated. These inputs allow the DDM to detect a window UP or DOWN request from the driver door switch. The DDM provides power and ground to both of the left window switches. When the left window up switch is activated, a ground is supplied through the left window up switch to the window up input which is pulled low. When the DDM detects low voltage on the window up input, the DDM will command the driver window up. If the DDM detects low voltage on the driver window down input, the DDM will command the driver window down. If the passenger window is operated from the driver window switch, the DDM will send a message on the serial data line to the passenger door module (PDM) to operate the passenger window up or down. The passenger window operates the same as the driver window except the PDM is receiving the passenger window switch input and controlling passenger window output functions. The door modules provide both power and ground through the power window motor left front up control and power window motor left front down control circuits to the window motors. The up and down output operation is similar to one another except that the polarity of the voltage applied to the window motors is reversed.

The driver and passenger windows have an express down feature. This feature allows the door modules to activate the driver or passenger window down without holding the window down switch for the entire duration. To activate this feature, momentarily press either window switch for one-third of a second and release. The door modules will lower the selected window completely down. The express down feature can be discontinued at any time by pressing the window switch again.