Window System Description

The window control switches on the console are mechanically interlocked so that they can only be operated in one direction at a time. When the DOWN switch is pressed, battery voltage passes through the DOWN switch contact to the respective WDO_DN terminal on the body control module (BCM). This voltage not only passes through to the motor to commence it moving the window down, but also passes to the BCM's AUTO_WDO_DN input. This means that when the window button is pressed, the BCM checks to see if the button activation time is greater than 0.4 second and less than 1 second (which represents a momentary press). If it is a momentary press, then the BCM energizes the AUTO DOWN WINDOW relay to complete the circuit until the window has reached the fully DOWN position. The BCM also calculates the time required to keep this relay energized to complete the process. When window movement is completed, the BCM de-energizes the relay, and the window control circuit reverts to normal. If the driver activates either the UP or the DOWN buttons momentarily while the window is traversing downwards, the window will stop moving downward and remain at that point. If the UP button is raised continuously, the window will first stop, the relay will de-energize and the window will then move upwards as directed by the UP button. There is no AUTO UP function associated with window movement. When the UP button is lifted while the window is down, the battery polarity presented across the window motor is reversed.