Hyundai SX2 Owner's Manual page 98

Seats & Safety system
Airbag non-inflation conditions
2C_AirbagNonOperatingConditionMinorCrash
In certain low-speed collisions, the
airbags may not deploy. The airbags are
designed not to deploy in such cases
because they may not provide benefits
beyond the protection of the seat belts.
2C_AirbagNonOperatingConditionRearCrash
Front airbags are not designed to inflate
in rear collisions, because occupants are
moved backward by the force of the
impact.
2C_AirbagNonOperatingConditionSideCrash
3-58
Front airbags may not inflate in side
impact collisions, because occupants
move in the direction of the collision.
Side and curtain airbags may inflate
depending on the severity of impact.
2C_AirbagNonOperatingConditionSidlingCrash
In an angled collision, the force of impact
may direct the occupants in a direction
where the airbags would not be able to
provide any additional benefit, and thus
the sensors may not deploy any airbags.
2C_AirbagNonOperatingConditionTruckCrash
Just before impact, drivers often brake
heavily. Such heavy braking lowers the
front portion of the vehicle causing it to
"nosedive". This is particularly important
when the vehicle in front has a higher
ground clearance. Airbags may not inflate
if your vehicle is in a "nosedive" condition
because the collision forces detected by
the sensors may have been significantly
reduced.