Pretensioners / seats etc

[paul]

when i obviously dont put my seat belt - the alarm and light stay on for about a minute i would say - (this is the drivers seat)

Does this happen in the passenger seat? or is it just the light that stays on??

How does it know to do this?? is is "bums on seats" that detects your on the seat but havent put your seatbelt on ? :S

Thanks all