Crash sensors for side airbags are usually installed inside the bottom of the “B-pillar,” the post behind the front door that helps hold up the roof. In some vehicles, these crash sensors are inside the front door or near the back seat area.

Your car, truck, van or SUV usually has at least one crash sensor on each side of the vehicle. During a side impact crash, the side airbag sensor should detect the sideways (lateral) deceleration and send an electrical signal to the airbags to begin inflating.

Side airbags are most commonly installed inside your seat, attached to the upper part of the seat frame nearest the door. In a few vehicles, the side airbags are installed inside your door, beneath the plastic trim cover. These side airbags are designed to provide a protective cushion between you and the side of your car.

3 Types of Side Airbags

• “Torso” airbag – Rectangular in shape, it protects only the torso or upper body and is often less than 18 inches tall when fully inflated. These airbags usually provide very little protection to your head and neck.
• “Head and torso” airbag – Taller than a regular torso bag, this type of airbag protects you better in a vehicle accident by protecting your head, neck and chest from the side of your car and the vehicle that hit you. This is particularly true when you are hit in the side of your vehicle by a taller vehicle, such as a pickup truck, van or SUV.
• “Curtain” airbag – A curtain airbag deploys downward from the edge of the roof and is intended to cover most of the window so your head and neck are protected, even when you would otherwise move outside the window during the accident.

For maximum protection, curtain airbags are sometimes combined with torso airbags that deploy from the seat or door trim to protect your chest. In many cases, such curtain airbags extend from the front seat toward the back, and can thus also protect back seat passengers.

In prior years, other types of side airbags were sometimes used, but on a much smaller scale. For example, a few cars used a tubular protection system consisting of an airbag shaped like a tube that ran from the front to the back of the door, extending across the window.

These systems need a separate torso airbag to adequately protect your chest. Often, there were significant disadvantages associated with such side airbags that resulted in limited use.