Actually, it doesn’t, but it can make a good guess. The majority of us back up most often just after we start our car (backing out of a parking space, driveway, or garage). So, when you start your car and the power outlet powers up (this is not applicable for power outlets that are on 24/7), the QuickVu™ monitor comes on and requests a video signal from the camera. The camera stays on for a predetermined length of time (the adjustable delay is preset to 30 seconds) and then turns off automatically. You can also turn on the camera with a simple tap of a button on the monitor, so you can back into a parking space, etc.
Because camera activation is not tied to the reverse gear, you can activate the camera even when driving in forward gears. This can be handy if you need to check on the tarp on the trailer, keep an eye on livestock, or just be sure you have completely passed the vehicle on the right before changing lanes.