Circuit/System Description
WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
The info display module has continuous power and ground. When the radio is on, a discrete 12 V signal is supplied on the radio controls wakeup circuit to the info display module. This signal is used to control the power state of the module, which is active when the signal is high and inactive when the signal is low.
The info display module receives digital video data from the radio for on-screen display information through the video signal circuits. Backlighting dimming level is controlled by the radio through a pulse width modulated circuit. The output is determined by dimming level information the radio receives via serial data.