The reaction produces nitrogen gas, which inflates the air bag. The inflator, air bag, and related hardware are all part of the air bag module packed inside the steering wheel. The air bag is designed to inflate in moderate to severe frontal or near-frontal crashes. The threshold level can vary, however, with specific vehicle design, so that it can be somewhat above or below this range. If your vehicle strikes something that will move or deform, such as a parked car, the threshold level will be higher.
Inflation is determined by the angle of the impact and the vehicle's deceleration.
No, it should not deploy under this condition if the snowplow trip mechanism is operational. No, the air bag is designed to deploy in the event of a front or front corner impact of sufficient severity. Inflation of the air bag during a rollover, side, or rear impact would not help the occupant. GM engineering performs barrier tests, sled tests, durability tests and field tests to validate the SIR system. Field testing involved a total of 11 snowplow fleets in various regions across the U.S. and Canada.