Airbags are a crucial safety feature in all modern cars. Frontal airbags can reduce driver fatalities by up to 30%, while side airbags can reduce fatal incidents by more than 50% in some car models. When your airbag warning light comes on, this is an indication that one or more of your airbags is not working. Here is everything you need to know about the airbag warning light.
Why Is My Airbag Warning Light On?
When the airbag warning light comes on, this indicates a problem with the airbags themselves or the system used to sense or control the airbags. If this light is on, the airbags are unlikely to deploy in case of an accident.
What Is the Airbag Warning Light?
The airbag warning light is a red or amber-colored light in the middle of your dials in the instrument cluster. It can also be found to the left or right of these clusters. It looks like a person seated with their seatbelt on with a circle in front of them to depict the airbag. Sometimes, the warning light is just the words “AIR BAG” illuminated by a red light.
What Does It Mean When the Airbag Warning Light Is Flashing?
A flashing warning light (which is fully on in many models) indicates that the airbags are deactivated. They will not deploy due to this as there is an issue with the airbags or related systems such as the seat belt sensors.
How Does the Airbag Warning Light Work?
There is a lot of sensors in your car connected to a lot of things. One of these is the airbag system, including its wiring, the warning light, and associated systems. When a fault is detected on one of these systems, the sensor sends a signal to your car’s computer system. The computer system causes the airbag warning light to come on until the underlying issue is corrected and the warning light reset.
What Are the Common Reasons the Airbag Warning Light Will Come On?
Depleted Airbag Backup Battery
Many cars now come with an airbag backup battery that powers the airbags independent of the main battery. If the main battery gets completely drained, the backup battery can also go completely flat which is then indicated by the airbag warning light. This situation is rectified once the main battery is fully charged, which is accompanied by the backup battery getting recharged.
Do note that this does not happen automatically in cars where the sensor needs to be reset in addition to the backup battery is fully charged.
Faulty or Damaged Sensors
Modern cars have numerous sensors connected to different systems. These sensors are connected to the car’s computer system to notify you of any issues with the car. Faulty sensors can cause the airbag warning light to come on even in cases where there is no issue with the airbags themselves.
These sensors can become faulty over time or be damaged in accidents where the airbags did not deploy. In some cars, the warning light can also come on if there is a jerky movement due to braking that causes tension in the seatbelts.
This tension is meant to protect you from striking the airbag or steering wheel, but it can also cause the seat belt pre-tensioner sensors to become faulty. This issue often comes up like an airbag warning light. The airbag sensors and seat belt pre-tensioner sensors will have to be checked in these cases. You can take your car in for a diagnosis to see which sensor is the problem. You can book a diagnostic online here.
Wiring Fault
Various electric faults can also cause the airbag warning light to come on. A common wiring fault is a wet airbag module which can be short due to water getting into your car. Other wiring issues require a thorough diagnosis that you can book above.
Damaged Clock Spring
The clock spring completes the circuit of the car by providing continuity between this wiring and the driver-side airbag. This spring winds and unwinds as the steering wheel turns meaning it can be worn out over time. This causes a poor or discontinued connection leading to an airbag malfunction.
Airbag Not Reset
Once your airbags deploy in an accident, the airbag warning light might not turn off until the system is reset. In these instances, it is not enough to have the airbags, clock spring, crash sensors, seat belt pre-tensioners, and other components replaced, and the system checked. The airbag monitoring unit (which might be called something different by a mechanic) will have to be checked and reset.
Is It Dangerous to Drive with My Airbag Warning Light On?
An airbag warning light is very serious because most cars will not deploy the airbag if this light is on. Additionally, there is no way of knowing if it will deploy or not in cars that deploy it even with the light on. It, therefore, follows that it is incredibly dangerous to drive with the airbag warning light on no matter how good of a driver you are.
How Much Does It Cost to Fix the Airbag Warning Light?
The cost of the repair will depend on why the airbag light is on. Issues such as a drained backup battery are easier to diagnose and thus, they are cheaper. Issues like faulty wiring are more complex. The cost of replacing the seat belt pre-tensioner is about £110, the airbag sensor is about £200 and the cost of finding faulty wiring will vary by make and model as well as other factors. Do note that replacing a deployed airbag costs about £500 for each airbag.
Will My Car Fail Its MOT If the Airbag Warning Light Is On?
Yes, a flashing airbag warning light or one that is on is a major violation. The reason why this is a failure is that your airbags and/or seatbelts have a direct impact on your safety. To avoid this, you should have the underlying issue corrected, the airbag corrected, and the warning light reset to pass.
About Fixter
Fixter is revolutionising the car maintenance industry, one repair at a time. Fixter was founded to make car maintenance as easy as booking a taxi. Digital, transparent and stress-free, with world-class customer service. Since launching in Manchester in 2017, Fixter has expanded to more than 100 towns and cities across the UK and provided thousands of car owners with honest, convenient and affordable car repair services.