Safety Systems - Horn, Airbags, & Seat Belts

Team BlueStar Inspections

Safety is a primary concern when designing and building automobiles. Driving remains the single most dangerous activity we perform on a daily basis. The weight of an average modern vehicle is about 4,000 pounds. A 4,000-pound vehicle traveling at 60 mph has an energy of about 500,000-foot-pounds. No, that's not an error. Foot pound is an engineering term used to describe units of force, and trust me: that's a lot of destructive, and potentially deadly force if your vehicle hits or gets hit by another vehicle. Manufacturers are mindful of this when it comes to developing vehicle safety systems.

Three of the most important vehicle safety systems are the horn, airbags, and seat belts. Most drivers don't give much thought to these systems until they're needed. However, proper attention to and maintenance of these systems can mean the difference between a scary situation and a fatal one. Each of these critical safety systems should be inspected on a regular basis to make sure they are operational and functioning properly. Let's discuss each of these vehicle safety systems and how to inspect them.


The horn is used to warn others of a vehicle's approach or presence, or to call attention to a hazard. The horn is easy to inspect. Press the horn pad or button. The horn should immediately make noise and be loud enough for other drivers to hear, even in traffic, with the windows rolled up and the radio on. The sound level of a typical vehicle horn is approximately 100-110 decibels, similar to the noise level of sitting close to a rock band in a concert, or the sound of a jackhammer in use nearby.

Horns can be used singly but are often arranged in pairs to produce a sound consisting of two notes. The use of two different frequencies makes the sound more perceptible than the use of two horns of identical frequency, particularly in an environment with a high ambient noise level such as that of a freeway or busy road. Levels of freeway traffic noise typically range from 70 to 80 decibels at a distance of 50 feet from the highway, which is similar to the level of noise a vacuum cleaner creates in a house.

In an effort to increase occupant comfort, vehicle manufacturers are designing vehicle interiors to be much quieter than they once were. This makes it harder for those inside the vehicle, particularly the driver, to hear outside noises. Horns must be audible even with these technology and comfort improvements.


When purchasing a used vehicle, find out if the airbags have been deployed. If airbag deployment has occurred, the airbag(s), module(s), and cover(s) must all be replaced. The electronics and sensors involved in airbag deployment should also be inspected and replaced if needed.

When an airbag deploys, the airbag cover splits apart. A split cover can be cosmetically repaired. Look and feel for any unevenness in the cover. Inspect for seams and repainting which will appear new and fresh compared to the rest of the interior. Inspect the airbag cover to see if it has the vehicle manufacturer's logo and/or the SRS logo which would indicate it is the original equipment, or an original equipment manufacturer (OEM) replacement part.

Another indication of airbag deployment is dashboard replacement. When airbag deployment occurs, the passenger side airbag will deploy as well. Airbag deployment will cause the dash to split open, resulting in the need for replacement.

The airbag indicator light can alert you to airbag system trouble. Turn the ignition key to the first position then pause to make sure the airbag indicator light illuminates. This will confirm the bulb is working. Turn the ignition to the start position and start the vehicle. The airbag light should turn on momentarily then go out. If the light stays on or flashes, there is a problem with the airbag system that needs to be diagnosed and repaired.

The repairs that follow an airbag deployment can be an expensive undertaking. Unfortunately, some unscrupulous salespeople and/or mechanics may only perform cosmetic repairs to make the system appear functional. Ask any seller detailed and specific questions concerning the accident history of the vehicle. A Carfax or Autocheck report can help provide transparency regarding the vehicle's history. If a vehicle has been involved in an accident, unless the vehicle only sustained minor damage to the sides or the rear, the airbags were likely deployed. Even with the vehicle history report in hand, always take the vehicle to a trusted mechanic for an impartial third-party inspection.


Seat belts should be inspected regularly to ensure they are in good condition and don't pose a threat to your safety and the safety of your passengers. When inspecting seatbelts, search for any cuts, frayed webbing, excessive sun exposure, retractability, proper latching and unlatching, and comfort while wearing.

The belts should pull out of the retractor easily, buckle securely, easily release from the latch, and automatically retract fully back into the unlatched position. Buckles and retractor mechanisms should be securely attached with retaining bolts to the vehicle's unibody, cab, or floor. Inspect seat belt buckles for cracks, damage, and for blockage caused by coins, food, or other small objects.

The seatbelt light on the dash should be illuminated when the seat belts are not buckled and should turn off when the seat belts are buckled. Faulty seatbelt components may also result in the airbag light turning on.

When purchasing a vehicle, always find out if the vehicle has been involved in any kind of accident. If the vehicle has been involved in an accident, the horn, airbags, and seat belts must be thoroughly inspected by a qualified technician. Do not assume they are working properly. A poor assumption may cost someone their life.