For some reason the 'Passenger air bag off' light keeps illuminating every now and then. I can't seem to figure out why it flashes, sometimes it's on constantly and other times it goes away for good. I've been reading lots of stuff saying I have to pull apart the console etc. My sister says her F150 has a weight sensor in the passenger seat and it lights up when there is nobody sitting in the seat.

Anybody know exactly what the issue here is or if this is a normal occurrence? Thanks