Hyundai Elantra N Owner's Manual page 80

Just before impact, drivers often brake
heavily. Such heavy braking lowers the
front portion of the vehicle causing it
to "ride" under a vehicle with a higher
ground clearance. Air bags may not
inflate in this "underride" situation
because deceleration forces that are
detected by sensors may be significantly
reduced by such "underride" collisions.
Front air bags may not inflate in
rollover accidents because front air bag
deployment would not provide additional
occupant protection.
However, the side and curtain air bags
may inflate in a rollover situation, when it
is detected by the rollover sensor.
OCN7N031054L
Air bags may not inflate if the vehicle
collides with objects such as utility poles
or trees, where the point of impact is
concentrated and the collision energy is
absorbed by the vehicle structure.
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03
OCN7N031055
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