Heres a brainteaser for ya
 

Ok I have the pioneer touchscreen 4300dvd unit in my car. Love the thing to death. However I noticed an irritating problem. When it is very cold outside(30 or below) When I start the car, the unit will turn on for 3 seconds and power off completely. There is no power at all going to the unit. However if I shut the car off and try it again it will stay on. Try and figure that one out.

Do you have any low battery light or anything come on? Ikn pioneer is good for that if ur battery is low itll shut itself off

Could just be the cold.. I have an issue with my ipod(since I always leave it in car). When its really cold like in teens or below my ipod locks up and wont function till it warms up.

i have an old kenwood that won't work in the cold :( ...i'd assume that there's probably a minimum operating temp. on one or two of the components and that initial surge of power from turning it on the first time generates enough heat or electrical charge to wake them up. Complete guess, but i'd assume it's something like that

Yeah it a strange one for sure. Its really irritating having to start my car 2 times so I can listen to the radio. Perhaps I should email pioneer and see what they think about it.

to avoid starting your car twice, try just turning the key to on for 2-3 seconds and then turn the engine over. On my 06, turning the key to on turns all the components on and when i start the car it basically restarts them all again. just a thought....might work might not