Circuit/System Description
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The radio can control the video display brightness on vehicles equipped with rear seat entertainment (RSE) video. The radio varies a pulse with modulated (PWM) signal to the rear entertainment video screen to command the screen brightness.