Why does my airbag warning light come on?

Monday 26th August 2024

Don’t ignore an airbag warning light. If your vehicle’s airbag is faulty, it could fail to deploy in a collision, putting you or your passengers at risk. Formula One Autocentres’ guide explains the possible issues that may cause your vehicle’s airbag warning light to come on and how to get it fixed.

What is an airbag?

An airbag is an inflatable cushion, designed to protect the driver and passengers in the vehicle from impact in an accident. The airbags are typically located in the steering wheel and passenger dashboard, alongside the doors and seatbelts. Once the airbags are activated, they will help prevent the driver or passengers from hitting the dashboard, steering wheel or each other, when the vehicle brakes violently or is involved in a collision.

Are there different types of airbags?

Yes, these include:

Front – This type of airbag is in the passenger dashboard and steering wheel.

Knee – You can find this airbag underneath the steering wheel and glovebox.

Rear – This airbag protects passengers travelling in the back of the vehicle from head-on collisions. When fitted, it is deployed from the backrests of the front seats.

Side – These are usually found within the car’s doors and will be activated if the vehicle is involved in a side-on collision.

Seat – A seat cushion airbag is found in the seat bolsters, within the rear and front seats.

Curtain - These deploy from the roof or above the doors and are designed to protect people's heads.

What happens when the airbag goes off?

When the airbag sensors detect a collision, a chemical mix within the airbag produces a pulse of nitrogen gas that inflates the airbag within milliseconds of the impact. It will then deflate once a person has made contact with the cushion.

Reasons why the airbag warning light comes on

The airbag is switched off

Many cars have a manual switch to turn off the passenger airbag. This is often used when a child's car seat is installed in the front passenger seat. When you turn off the airbag, the warning light will illuminate to remind you that it is not in use. It will remain on until you reactivate the passenger's airbag again.

Faulty sensors

Sensors within your vehicles are connected to the car's computer system and will trigger a warning light if a fault is detected. Over time, the sensors in your car's airbag system can malfunction. This can cause the warning light to turn on even when there's no problem with the airbags. If your airbag warning light is illuminated, contact your nearest branch and our vehicle technician can identify the cause. If faulty sensors are to blame, we can fit new ones.

A faulty seat belt

When you start your car, the seatbelt warning light and airbag warning light may come on if your seatbelt isn't fastened correctly. If the seat belts are damaged, visit your local branch and we can replace your car’s seat belt sensors and belts.

A dead battery

If you don't drive your car for an extended period, the battery can die. This can affect the backup battery that powers the airbag, causing the warning light to flash on and off. You can resolve this by recharging the main and backup batteries to full capacity and a sensor reset. This can be done by:

Turning the ignition on and off.

Disconnect and reconnect a new battery if the current one is dead.

Reprogram, reset or replace your sensors with new ones.

Is your battery failing to charge? Book a free diagnostic battery check with Formula One Autocentres and we’ll get your vehicle running again.

Should you service airbags?

Airbags are designed to last the lifetime of the vehicle they're installed in unless damaged.

However, there are a few exceptions:

After a deployment: If your airbag has deployed in an accident, it will need to be replaced.

If the warning light is on and won't switch off: If the airbag warning light illuminates your dashboard, it indicates a problem with the airbag system.

It's important to note that while airbags don't need regular servicing, it's still a good idea to have your car's safety systems checked during routine maintenance to ensure they're functioning properly.

What do all the warning lights on your dashboard mean? Discover what might be wrong with our helpful guide. Get your vehicle’s airbag system reset or replaced by locating your local Formula One Autocentres branch and contacting our friendly team today.