Separately, your vehicle’s sun visors and airbags might seem harmless. But the combination of deploying airbags and in-use sun visors can have dangerous consequences, including possible blindness.

Here’s an actual incident that explains why:

A young man was driving a 2003 Mitsubishi Eclipse in a rural area. Because of the setting sun, his passenger had her sun visor down to shield her eyes.

As the car turned slowly into a Little League parking lot, its left front wheel struck a small post in the center of the driveway that was obscured by dust kicked up by other cars. Despite the low speed and the lack of any damage to the front bumper or front end, the airbags deployed.

As the passenger airbag deployed, it slammed into the passenger’s sun visor (sun shade), smashing it apart and sending pieces flying. As a result, our client was hit in the face and blinded in one eye.

The force from the deploying airbag was so strong it ripped a jagged metal insert from inside the sun visor through the visor’s plastic shell. The force was also strong enough to shatter the vanity mirror that was part of the sun visor.

What Our Airbag Tests Revealed

During our 2003 Mitsubishi Eclipse testing at an independent airbag test facility, we used real-time video cameras and sophisticated high-speed cameras. This testing video allowed us to capture the passenger airbag/sun visor interaction and clearly document how an airbag rips the sun visor off its attachments.

In every one of our tests, the passenger airbag smashed into the sun visor, ripped it off its attachments, and sent pieces flying through the cabin of the car, where it could pose a danger to the passengers.

Although this accident and our testing involved a 2003 Mitsubishi Eclipse, other cars present similar risks. For example, our investigation revealed the following vehicles sold in the United States all use the same or substantially similar passenger airbags and passenger sun visors as the ones we tested:

• 2000, 2001, 2002, 2003, 2004, and 2005 Mitsubishi Eclipse
• 2001, 2002, 2003, 2004 and 2005 Mitsubishi Eclipse Spyder
• 2001, 2002, 2003, 2004 and 2005 Dodge Stratus
• 2001, 2002, 2003, 2004 and 2005 Chrysler Sebring

Although other cars may use different airbags or different sun visors, you aren’t necessarily free from danger. For example, some vehicles may also have a passenger airbag that deploys upward, along the windshield, and that can strike a sun visor that is being used. At the same time, some other vehicles may have sun visors that are not specifically designed to stay together after being hit by an airbag.

1. Airbag Modules: As the heart of the airbag system, airbag modules include the fabric airbag cushion or “pillow,” the inflator that generates the gas that fills the airbag, and the container that holds them.

For front airbags, the driver’s airbag is in the center of the steering wheel, and the passenger’s airbag is in the dash in front of the passenger seat. Side airbags are generally in the side of the seat or behind the plastic trim next to the seat. Newer curtain, rollover or canopy airbags are located in the edges of the roof, and deploy down along the side windows.

These modules must contain certain specific safety features to prevent the airbag from causing unnecessary head, neck, chest or other injuries.

2. Airbag Sensors and Diagnostics: The crash sensors are the “brains” of the airbag system, deciding whether and when to deploy the airbags in an automobile accident or collision.

The diagnostic portion of the airbag system is intended to diagnose certain electrical problems within the airbag circuits. These diagnostics evolved into modern “black boxes” that record crash information and go by names such as:

• ECU (Electronic Control Unit)
• SDM (Sensing and Diagnostic Module)
• RCM (Restraints Control Module)
• ORC (Occupant Restraints Controller)
• EDR (Event Data Recorder)

Sensor failures can lead to airbags not deploying during a car accident where they should have protected a consumer. They can also lead to unnecessary deployments that can cause a crash to occur, or can directly injure a consumer.

3. Clockspring: An electrical component in the steering wheel, the clockspring allows electrical current to flow through the wires in the steering column to the driver airbag module mounted in the steering wheel. When this part is defective, it can prevent the driver’s airbag from deploying, even during a high-speed wreck. Millions of these components have been recalled, often due to a poor design, lack of testing, or inadequate quality control.

4. Warning Lamps: These warning lights in your instrument cluster or on your dash should show the electrical status of your airbag system. When you start your car, the warning lamp should flash or stay on for about six seconds while the diagnostic unit checks the system. If your warning lamp comes on while you’re driving, you probably have a defect in your airbag system, which could cause the airbag system to unnecessarily deploy or can prevent deployment in a crash.

5. Passenger Airbag On-Off Switches: In some vehicles, including pickup trucks and cars without a back seat, a key-operated on/off switch is located in the dash. These are typically intended to allow a driver to shut off the passenger airbag when infants or small children do not have an adequate back seat in which to sit and must instead sit in the front seat.

6. Passenger Presence Detection and Occupant Classification Systems: Newer advanced airbags include various methods to determine the presence and size of the front passenger, in order to adjust how forcefully the airbag should deploy.

If there is no passenger, or if an infant or child becomes too close to the dash, these advanced airbags are typically intended to prevent the deployment of the airbag. If the occupant is an adult, such systems can tailor the inflation force to the person’s size or position. A failure in these systems can have deadly consequences.

7. Other Components: Other parts of your car should also be designed to work together with your airbag system during a crash, including deployment doors, trim covers, knee bolsters, steering columns, steering wheels, sun visors, windshields, seats, dash or instrument panels (I/P), and sometimes even the inside rear view mirrors.

Although the process leading to airbag deployment has become more technical over the years, the airbag safety sensors’ job has remained the same.

In earlier vehicles, these airbag sensors were basic switches that responded to changes in velocity as the vehicle slowed down during the crash. Once two sensors “closed” to confirm a crash was taking place, electrical current was allowed to flow to the airbag modules.

In newer vehicles, electronic sensors measure a vehicle’s deceleration (negative acceleration), process it mathematically through a computer algorithm, and then compare the measured values to the values stored inside it from crash testing. If the measured values indicate the crash is more severe than the stored crash tests, the control module allows electrical current to flow to the airbag modules.

Once the electrical current flows to the airbag modules, it heats up a “squib” within the inflator that has a small filament inside a container of chemically explosive or flammable material. Once the filament gets hot enough, the chemicals begin burning. This sets off a larger reaction of a chemical called sodium azide within the inflator, which rapidly produces nitrogen gas, along with numerous byproducts.

In some vehicles, the sodium azide inflator was replaced with an inflator using pressurized gas, usually a combination of helium and argon. With either type of inflator, the gas from the inflator then fills the fabric airbag that was folded over the inflator.

As the gas fills the airbag, it increases in size, eventually breaking out from behind its plastic cover and inflating to its maximum size. Driver airbags are generally shaped like a round pancake – just larger than the diameter of the steering wheel – and are normally about 12 to 20 inches thick when filled. Passenger airbags are generally about 2 to 3 feet wide, and fill the space between the passenger and the dash or windshield.

Since passenger airbags are usually 2 to 4 times larger than driver airbags, they require a more forceful inflator to fill that larger size in the same amount of time.

For frontal airbags, the process of sensing the crash and inflating the airbags is usually over in less than one-tenth of a second. As the forces of the crash propel the driver/passenger forward into the airbag, it begins to absorb the energy by compressing and letting some of the gas out through the fabric or through specially designed vent holes.

This explains why many people involved in a vehicle accident in which airbags deployed remember the distinct chemical odor of the inflation gas and seeing smoke in the car.

For side airbags and rollover airbags, the process is similar. A sensor in the side structure of the car, or sometimes inside the front door, detects the rapid deceleration from the side or the vehicle beginning to rotate upwards during a rollover crash. Electrical current is then sent to the side airbags or to the rollover airbags (depending on the type of crash), which causes those airbags to deploy. Although the chemicals and gases may be different than for front airbags, the inflation process is very similar.