Hyundai i30 (PD): Air bag - supplemental restraint system / Why didn't my air bag go off in a collision?

There are certain types of accidents in which the air bag would not be expected to provide additional protection. These include rear impacts, second or third collisions in multiple impact accidents, as well as low speed impacts. Damage to the vehicle indicates a collision energy absorption, and is not an indicator of whether or not an air bag should have inflated.

Air bag collision sensors

WARNING

To reduce the risk of an air bag deploying unexpectedly and causing serious injury or death:

• Do not hit or allow any objects to impact the locations where air bags or sensors are installed.
• Do not perform maintenance on or around the air bag sensors. If the location or angle of the sensors is altered, the air bags may deploy when they should not or may not deploy when they should.
• Do not install bumper guards or replace the bumper with a nongenuine part.This may adversely affect the collision and air bag deployment performance.
• Place the ignition switch to the LOCK/OFF or ACC position, when the vehicle is being towed to prevent inadvertent air bag deployment.
• We recommend that all air bag repairs are conducted by a HYUNDAI authorised repairer.

1. SRS control module
2. Front impact sensor
3. Side pressure sensor (front)*
4. Side impact sensor (rear)

Air bag inflation conditions

Front air bags

Front air bags are designed to inflate in a frontal collision depending on the severity, speed or angles of impact of the front collision.

Side and curtain air bags

Side and curtain air bags are designed to inflate when an impact is detected by side collision sensors depending on the severity, speed or angles of impact resulting from a side impact collision.

Although the driver’s and front passenger’s air bags are designed to inflate in frontal collisions, they also may inflate in other types of collisions if the front impact sensors detect a sufficient impact. Side and curtain air bags are designed to inflate in side impact collisions, but they may inflate in other collisions if the side impact sensors detect a sufficient impact.

Also, the side and curtain air bags are designed to inflate when a rollover is detected by a rollover sensor. (if equipped with rollover sensor)

If the vehicle chassis is impacted by bumps or objects on unimproved roads, the air bags may deploy. Drive carefully on unimproved roads or on surfaces not designed for vehicle traffic to prevent unintended air bag deployment.

Air bag non-inflation conditions

In certain low-speed collisions the air bags may not deploy. The air bags are designed not to deploy in such cases because they may not provide benefits beyond the protection of the seat belts.

Front air bags are not designed to inflate in rear collisions, because occupants are moved backward by the force of the impact. In this case, inflated air bags would not provide any additional benefit.

Front air bags may not inflate in side impact collisions, because occupants move in the direction of the collision, and thus in side impacts, front air bag deployment would not provide additional occupant protection.

However, side and curtain air bags may inflate depending on the severity, vehicle speed and angles of impact.

In an angled collision, the force of impact may direct the occupants in a direction where the air bags would not be able to provide any additional benefit, and thus the sensors may not deploy any air bags.

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.

Information

• Vehicles equipped with rollover sensor The side and curtain air bags may inflate in a rollover situation, when it is detected by the rollover sensor.
• Vehicles not equipped with rollover sensor
  The side and/or curtain air bags may inflate when the vehicle is rolled over by a side impact collision, if the vehicle is equipped with side and/or curtain air bags.

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.