It knows it's at home when the power jack is plugged in. If it's not plugged in, and it's still getting power, it thinks it's in the car

Does the power supply switch over to the plug if it senses the power jack, as well? I mean, could I plug in a "dummy" jack while it's docked to make it think it's at home?
Thanks,
Jason

_~= Dearing =~_
"WAY too happy about having #99."