installed a reverse camera in '99 Tahoe. AVH-P5200BT was already installed. Now, after a minute, the screen automatically switches to the reverse camera image after starting the car. Any ideas? I know some brands have a setting for that, but didn't see anything in 5200 menu.

check the camera polarity. at least that is what i think it is, and it is in the middle button (the gear pic) in the settings. and that is on the 6300bt but it should work with yours also.