Where are the sensors that setoff the airbag? What exactly triggers them?

 

From http://www.howstuffworks.com

The sensor is the device that tells the bag to inflate. Inflation happens when there is a collision force equal to running into a brick wall at 10 to 15 miles per hour (16 to 24 km per hour). A mechanical switch is flipped when there is a mass shift that closes an electrical contact, telling the sensors that a crash has occurred. The sensors receive information from an accelerometer built into a microchip.

From what I know there are basically little metal *****, and when you hit something at 10-15-20mph, these ***** fly foward and the microchip can measure their acceleration. If the acceleration reaches a certain level the airbag is deployed.

 

On the EG there on the interior of the firewall, one on each side. If you pull the carpet back, there's a heavy insulating matt underneath your pedals. Lift that up and there's a metal cover. Take those little screws off and pull it out. The passenger side sensor is symmetrical to the driver's side. You can follow the yellow wiring loom from the airbag ECU if you want.

 

ok cool.... i was wondering because my front end is kinda messed up from a crash before i got the car, so i'm not sure if everything is hooked up correctly or not....guess there is no real way to tell.

 

http://auto.howstuffworks.com/airbag1.htm