Slide 1. Introduction.
The class develops what causes the airbag light to come on, the consequences, and the implications for fleet management.
Slide 2. Airbag warning light on.
- What is an airbag?.
Airbags increase safety inside the car, as their function is to prevent the driver and passengers from hitting any part of the passenger compartment, such as the steering wheel, doors, or any other element.
The airbag is one of the fundamental passive safety systems incorporated into cars, and one that we don't usually think about until a warning light comes on in the instrument panel, either because we have had an accident or because there has been a fault.
When the airbag warning light comes on, it means that the system is not operational. For safety reasons, the car alerts us that this airbag is disconnected and will not work when needed. Therefore, it is essential to fix this problem as soon as possible.
It is not safe to drive with the airbag warning light on. The light indicates that there is a problem with the airbag, so in the event of an accident, it may not deploy properly. This reduces the effectiveness of the vehicle's safety features. Therefore, it is important to address the problem immediately to ensure safety.
- What faults can cause the airbag warning light to come on?.
The airbag light, which may be red or orange depending on the manufacturer, does not indicate which specific airbag is malfunctioning. It could be the driver's airbag, the passenger's airbag, the curtain airbag, the side airbag, or even the pedestrian airbag, which is stored under the hood of some cars and deploys to improve pedestrian safety in the event of a collision.
- Seat belts as a passive safety feature.
The airbag light may also come on due to the position of the seat belt. The seat belt buckle, where it is attached to the car body, has pretensioners that, in the event of an accident, prevent it from retracting and the passenger's body from being thrown forward.
For example, when we are at a traffic light and someone rear-ends our vehicle at low speed, these pretensioners are activated, even without the airbag being deployed, as the airbag only inflates in the event of sudden deceleration. If there is no impact, the airbag will not deploy. In this situation, the airbag warning light will come on without the airbag being deployed.
- After an accident.
Even if the airbags have not deployed, the system may detect an abnormal condition and activate the warning light. In such cases, it may be necessary to reset or professionally repair the airbag system.
- Airbag warning light malfunctions.
The airbag warning light on the instrument panel usually illuminates when there are faults in the connections. Airbag cables are usually located under the driver's and passenger's seats. If the seat is moved to slide the bench forward or backward, these cables can sometimes be damaged.
The solution is to disconnect and reconnect these cables. If the warning light is no longer present when you start the vehicle, the airbag problem has been solved. Some manufacturers recommend soldering these cables to prevent them from becoming disconnected and subsequently failing. However, this is a task that is only recommended for people with welding experience and always with the battery disconnected. You can always go to a specialized workshop to have this task performed.
- Wear and tear on the airbag clock springs.
One of the steering wheel components related to the airbag is the “airbag clock.” This component can wear out over time, as it is constantly manipulated in its location. It connects the bag mounted inside the steering wheel to the electrical system. This is a serious problem, as it renders the system inoperative in the event of an accident.
In this case, removing the steering wheel is complex and requires diagnostic devices to reconfigure the system. It is best to go to a repair shop, where you will be charged between 300 euros and 400 euros.
- Faulty sensors.
Crash sensors are essential components that detect sudden deceleration during a collision and activate the airbags. If one of these sensors fails, the airbag light will remain on. Faulty sensors may need to be replaced.
- Damage to the airbag wiring.
Problems with the airbag system wiring can cause false signals or prevent the airbag from deploying. This can occur due to corrosion, wear and tear, or if the wiring has not been handled carefully during repairs.
- Airbag backup battery depleted.
The airbag system relies on this battery to function in the event that the car's main battery fails. If this battery is depleted, the SRS warning light may come on. The backup battery may need to be replaced.
- Airbag control unit.
Although these are the most common causes, there are others that are more difficult to detect. For example, the airbag management system is very sensitive to voltage drops when starting the car if the battery level is low. A voltmeter is an effective tool for checking the condition of the battery. If the value is between 12.3 and 13.5 volts, there is no problem. If it is lower, consider replacing the battery. The age of the vehicle can also cause malfunctions, as manufacturers set a service life of about 15 years for the airbag and all its associated systems.
- Wet airbag module.
The airbag can be damaged if exposed to external agents such as water. This is one of the most common reasons why the airbag warning light comes on without the need for repair. This usually occurs in cars that have been exposed to heavy rain, such as in the case of flooding, or in cases where the owners have spilled liquids on the seat.
In today's cars, the airbag module is located just below the seats. It is usually upholstered and waterproofed, although frequent use can wear out these coverings. Corrosion of the module due to moisture can activate the emergency warning lights.
- Weight sensor.
A fault in the passenger seat weight sensor is another possible malfunction related to the airbag warning light. This sensor determines whether someone is sitting in the passenger seat and is activated when a minimum weight is exceeded.
It is very important that this sensor works properly. If it is not operational, the airbag will not activate in the event of an accident. This sensor is designed to save costs in the event of an accident: why would an airbag deploy if there is no one in the passenger seat?.
The airbag warning light should not be confused with the light that comes on when we disconnect the passenger airbag. We will only disconnect this airbag when we are carrying a baby in a child seat. The most recommended and legal option, with some exceptions, is to carry the baby in the back seat in a rear-facing seat.
- Replacing an airbag is expensive.
In most cases, when an airbag has deployed, the steering wheel must be replaced, except for the rim, because the bag is integrated into this part. In the case of the passenger seat, the part of the dashboard where the bag deployed must be replaced. If the pedestrian airbag has been activated and has not been damaged, it does not need to be replaced like the others. It could be put back inside the hood at the height of the windshield wiper so that it would work again. However, in this case, the light would remain on and would have to be removed from the diagnostic system.
The cost of replacing this part is high, exceeding 300 euros, because, in addition to the airbag, the control unit and electrical system must be replaced, as recommended by the manufacturers, and subsequent programming must be carried out.
- Airbag failure: serious defect in the MOT.
One of the procedures carried out during the Vehicle Technical Inspection-MOT is to check that the airbag is working properly. During the inspection, they check that the airbag warning light goes out a few seconds after turning on the ignition and starting the vehicle's engine. If the warning light does not go out, it is considered a serious defect and the MOT will be unfavorable.
- Implications for fleet management.
The main consequence of the airbag light being on is that the airbag will not deploy in the event of an accident, with possible injuries to the vehicle occupants, and the vehicle will not pass the MOT test.
The following measures are recommended.
- Airbag maintenance.
Airbag maintenance must be carried out according to the vehicle manufacturer's instructions and within the specified time frame.
- Vehicle use.
If the airbag light is on, it is recommended not to use the vehicle until the airbag has been repaired and the warning light is no longer on.
- Driver training.
The driver must notify the fleet manager or workshop manager that the airbag light is on as soon as possible.
- Remote diagnosis.
If remote diagnosis is used, we will know in real time that the airbag light is on. It is recommended to set up an alert in the remote diagnosis software to notify us.
- Airbag replacement.
If the airbag has been deployed in an accident, it is recommended that it be replaced with an original one. It is not recommended to use one of dubious origin.
Slide 3. Thank you for your time.
The class has developed what causes the airbag light to come on, the consequences, and the implications for fleet management, see you soon.
