Pioneer Avh-p4400bh Will Not Allow Dvd Playing While The Vehicle Is Moving????

This unit has a safety feature that prevents it from playing back DVD unless the handbrake/e-brake is activated. There is a wire that you need to hook to the handbrake/e-brake for this - if your vehicle is a show or off road vehicle, or if you simply don't care for your stereo telling you what you can and cannot do, you can purchase a bypass (it's a simple automotive relay) for this and wire it up, the relay will provide a ground to that green wire each time you go to watch a video and remove that message. You cannot simply ground the green wire, because you would have to re-ground it each time you apply power (turn on the key). You could however hook the green wire to a switch, but the relay is much nicer. If you go on eBay there are preassembled bypass relays that you can get for $10 free shipping, little micro ones too. Just look for pioneer bypass. Have a great day!