John Austin | May 2, 2025 | Car Accidents
Generally, a collision has to be a moderate to severe frontal or near-frontal crash for airbags to deploy. But what does that mean, and how does your car know you’ve been involved in a crash? Will they go off in every collision, and what happens if they don’t go off when you need them to? As experienced injury lawyers in Clearwater, FL, we have seen our fair share of car crashes.
A personal injury lawyer investigates these complex situations on your behalf. They help you challenge what the insurance company says and protect your rights.
Key Takeaways
- The deployment threshold is similar to hitting a solid wall at 8 to 14 miles per hour.
- Factors like impact direction, speed, and sensor location affect airbag deployment.
- Airbags may not deploy in rear-end, side-impact, or rollover crashes.
- A failure to deploy doesn’t automatically mean the airbag system is faulty, but it requires investigation.
Understanding Airbag Deployment Systems
Modern vehicles contain a sophisticated network of sensors and a central control unit that decides when to deploy the airbags. This system is called the Supplemental Restraint System, or SRS. The SRS works with your seatbelts to protect you during a crash.
It’s not a replacement for wearing a seatbelt.
The Role of Crash Sensors
Crash sensors are the key to airbag deployment. These devices detect the sudden deceleration that happens in a collision.
Your car likely has several sensors placed in strategic locations:
- Front Sensors: These are typically located at the front of the vehicle, often behind the grille or on the radiator support structure. They measure the severity of a frontal impact.
- Central Control Unit: This unit, also known as the airbag control module, is the system’s brain. It receives data from the sensors, analyzes the crash forces, and makes the final decision to deploy the airbags.
- Safing Sensors: Your vehicle also has safing sensors. These act as a fail-safe to prevent accidental deployment. The control unit needs signals from both the primary crash sensors and the safing sensors before it activates the airbags.
The system evaluates crash data, assessing the force and direction of the impact to determine if the collision meets the criteria for deployment. If it does, the control unit sends an electrical signal to the airbag inflator.
The Chemical Reaction That Deploys an Airbag
Once the inflator receives the signal, it triggers a rapid chemical reaction. This reaction produces a large volume of harmless nitrogen gas. The gas inflates the nylon airbag, causing it to burst out of its housing in the steering wheel, dashboard, or other location.
The entire process, from impact to full inflation, happens in the blink of an eye. The airbag then immediately begins to deflate through small vents. This controlled deflation absorbs the force of your forward motion and cushions your impact.
Factors That Influence Airbag Deployment
A modern to severe impact is roughly equivalent to hitting a solid, fixed barrier at about 8-14 miles per hour. However, several other variables determine whether your airbags deploy in a collision. It’s not just about the speed you were traveling.
The system considers the complete picture of the crash dynamics. A crash that feels severe to you may not meet the specific engineering parameters required for deployment.
Impact Speed and Direction
The system measures the change in speed, or deceleration, not just the travel speed. A crash into a parked car at 30 mph creates a different deceleration force than a head-on collision with another car moving at the same speed.
The direction of the impact is just as significant:
- Frontal Collisions: Front airbags are designed explicitly for frontal and near-frontal impacts. They offer the most protection when the force of the crash is directed at the front of your car.
- Side Impacts: In a side-impact collision, or T-bone crash, the front airbags may not deploy. Your vehicle may have separate side-impact airbags and curtain airbags designed to protect you in these types of crashes.
- Rear-End Collisions: If you’re rear-ended, your front airbags aren’t designed to deploy. The force of this type of collision pushes you back into your seat. The headrest and seatbelt are your primary safety features in a rear-end crash.
- Rollovers: During a rollover, the deployment of front airbags isn’t always helpful and may even cause additional injury. Some vehicles have advanced systems that use sensors to detect a rollover and deploy side curtain airbags and activate seatbelt pre-tensioners.
The Object You Hit Matters
What your vehicle collides with also affects the airbag system’s decision. Hitting a solid, immovable object like a concrete wall produces a very different crash pulse than hitting a deformable object like another vehicle.
Striking a narrow object like a pole or a tree may not trigger the sensors, even at high speeds. The impact force might be concentrated in a small area that the primary crash sensors don’t cover.
An underride accident happens when your car slides under a larger vehicle, like a semi-truck. The main impact may be to the upper part of your car, bypassing the front sensors entirely. In these cases, the airbags may not deploy despite the severity of the crash.
Other Contributing Factors
Other elements also play a part in the complex calculation for airbag deployment:
- Seat Occupancy: Advanced airbag systems use sensors to detect if a passenger is present. They also weigh the passenger to determine if the airbag should deploy and at what force. The system may suppress the passenger airbag if a child or small adult is in the seat.
- Seatbelt Use: The SRS is designed to work with your seatbelts. Some systems may adjust the deployment force based on whether the occupants are wearing seatbelts.
- Braking: Heavy braking just before impact causes the front of your vehicle to dip downward. This change in vehicle position alters the point of impact and may affect how the crash sensors read the collision forces.
When Non-Deployment Indicates a Problem
While airbags aren’t meant to deploy in every crash, there are situations where a failure to deploy points to a defect. If you were in a moderate to severe frontal collision and your airbags didn’t inflate, it’s a cause for concern.
Potential Defects in the Airbag System
Several issues can lead to airbag failure. These problems may stem from the vehicle’s design, manufacturing, or even maintenance. A thorough investigation is often necessary to identify the exact cause.
Potential issues include:
- Faulty Sensors: The crash sensors themselves may be defective. They might fail to detect the crash forces correctly or fail to send a signal to the control module.
- Wiring Problems: The wiring that connects the sensors to the control unit and the control unit to the inflator may be damaged or improperly installed. A break in this communication path prevents the deployment signal from reaching its destination.
- Defective Control Module: The airbag control module is a small computer; like any computer, it can fail. A software glitch or hardware malfunction may prevent it from processing the sensor data and making the correct decision.
- Improper Repairs: If the vehicle was in a previous accident, improper repairs to the airbag system or the vehicle’s structure may cause a failure in a subsequent crash.
Takata Airbag Recalls
The massive Takata airbag recall is one of the most well-known examples of airbag defects. This recall affected tens of millions of vehicles from numerous manufacturers. The issue involved the chemical propellant used in the inflator.
Over time, exposure to heat and humidity caused the propellant to degrade. When the airbag deployed, the degraded propellant could explode with excessive force. This explosion sent sharp metal fragments flying into the passenger compartment, causing serious injury or death.
This recall highlights how a single defective component can have devastating consequences.
How a Personal Injury Lawyer Helps With Your Airbag Case
Airbags save lives, but the force of their deployment can cause injuries. Likewise, when an airbag fails to deploy in a serious crash, the occupant may suffer severe injuries that the airbag was designed to prevent.
An attorney investigates the complex technical and legal issues involved in an airbag failure claim and works to hold the responsible parties accountable for your injuries.
Investigating the Crash
A lawyer gathers all the evidence related to your accident. This includes the police report, witness statements, and photos of the scene and your vehicle.
They may hire accident reconstruction experts to analyze the crash dynamics and determine if the impact should have triggered the airbags.
Preserving Key Evidence
Your vehicle is a critical piece of evidence. A lawyer takes immediate steps to have the vehicle preserved in its post-accident state. They know who to call to inspect the airbag system and download data from the vehicle’s event data recorder, or black box.
Identifying Liable Parties
The liable party might be the vehicle manufacturer for a design or manufacturing defect. It might be the manufacturer of a specific component, like the sensors or the control module. If the vehicle had prior repairs, a mechanic or auto body shop might be responsible.
Your personal injury lawyer’s investigation helps uncover all potential liable parties.
Defending Your Rights
Car manufacturers and their insurance companies have teams of lawyers to defend them against these claims. They may argue that the crash wasn’t severe enough for deployment or that another factor caused your injuries.
Your lawyer counters these arguments with strong evidence and expert testimony to build a compelling case on your behalf.
FAQ for How Serious Does a Collision Have to Be for Airbags to Deploy?
Why Didn’t My Side Airbags Deploy in a Frontal Crash?
Side airbags are designed to protect you during side-impact (T-bone) collisions and sometimes rollovers. They deploy from the side of the seat or the door panel to cushion the impact from the side.
They’re not intended to activate in a direct frontal or rear-end crash because the front airbags and seatbelts are the primary safety systems for those types of accidents. Each airbag system has its own set of sensors calibrated for specific impact directions and forces.
What Types of Accidents Do Not Cause Airbags To Deploy?
Airbags aren’t designed to deploy in every accident. They likely will not deploy in minor fender-benders, rear-end collisions, side-impact crashes (unless the vehicle has side airbags), or rollovers.
The system is calibrated to activate only when the crash forces indicate a high risk of serious injury from hitting the vehicle’s interior.
Can an Airbag Deploy Without a Crash?
It’s extremely rare, but an airbag can deploy without a collision. This may happen due to a severe electrical system malfunction or a defect in the airbag control module.
In very rare instances, hitting a large pothole or curb with significant force may also generate enough of a shock to trick the sensors into deploying the bags.
If My Airbag Warning Light Is On, Will My Airbags Still Work?
If the airbag warning light on your dashboard is illuminated, it signals a fault in the Supplemental Restraint System. When this light is on, your airbags may not deploy in a crash. If this is the case, you need to get your vehicle serviced by a qualified mechanic to diagnose and repair the problem.
What Should I Do if I Think My Airbags Should Have Deployed but Didn’t?
If you were in an accident and believe your airbags should have deployed, you need to preserve your vehicle as evidence. Don’t let it be repaired or scrapped, and contact a personal injury lawyer to discuss your situation. They can help investigate whether a defect in the airbag system caused it to fail.
Get the Answers You Need
When an airbag fails, the consequences are devastating. You may be left with serious injuries and mounting questions. You don’t have to find the answers alone. Roman Austin can help you hold the responsible manufacturer accountable for the harm their defective product caused.
If you were injured in a car accident and the airbags failed to deploy, contact us for a free case evaluation. Call Roman Austin now at (727) 787-2500.
Your airbags are designed to protect you in the event of a crash, and it may not take as much force as you think to set them off. A crash at 10 to 16 miles per hour is considered “moderate to severe” and could be enough to deploy your airbags. Once your airbags have gone off, you need to replace them in order for them to work the next time you’re in a crash.
If you’ve been hurt in a car accident, you could be entitled to compensation. Our car accident lawyers can stand up to the insurance companies and help you get the money you deserve. Schedule a free consultation with us today to start getting the representation you need in your case.
Contact the Clearwater Car Accident Law Firm of Roman Austin Car Accident and Personal Injury Lawyers for Help Today
For more information, please contact the legal team of Roman Austin Car Accident and Personal Injury Lawyers for a free initial consultation with a car accident lawyer in Clearwater. We have convenient locations in Florida: St. Petersburg, Safety Harbor, Clearwater, New Port Richey, and Tampa.
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