Why Is My Airbag Light On? (12 Reasons)

An airbag light typically turns on due to a self-diagnostic check during startup. When you start your car, the airbag control module conducts a brief system check to ensure all components, sensors, and the overall airbag system function correctly. Outside of this ideal scenario, however, the airbag warning light can be triggered by many factors.

Here are the 12 reasons why your airbag light is on:

1. Impact or Accident
2. Deteriorated Components
3. Malfunctioning Sensors
4. Software or System Glitch
5. Airbag System Issues
6. Charging System Problems
7. Faulty or Non-Working Clock Springs
8. Severe Temperature Conditions
9. Human Error or Oversight
10. Seatbelt Pretensioner Issues
11. Faulty Airbag Switch
12. Defective Airbag

Costs of fixing airbag warning light issues vary depending on the identified problem. Repair expenses can range from a few hundred dollars for minor sensor or wiring problems to over $1,000 for complex issues like airbag replacement or accident-related system malfunctions. To avoid such expenses, read on and learn more about the airbag system in today’s guide.

Afterward, visit my article on how to reset the airbag light to promptly address issues. After all, driving with your airbag light on is never okay.

Reasons Why an Airbag Warning Light Turns On

1. Impact or Accident

On-road collisions or accidents are the primary cause of an activated airbag warning light. These incidents can disrupt the intricate system designed to deploy airbags. Even minor accidents can impact the sensors, modules, and wiring of the Supplemental Restraint System (SRS), leading to an inaccurate interpretation of the situation. This misinterpretation, in turn, sets the airbag warning light off.

If you’ve been in an accident (even a minor one), it’s crucial to promptly inspect and address possible damage to ensure the continued effectiveness of the airbag system. Such cases may require inspection and potential reset.

2. Deteriorated Components

Airbag modules, sensors, wiring, and the airbag control unit are components within the airbag system that can trigger the activation of the airbag light. Like other car components, they’re susceptible to wear and aging over time, resulting in malfunctions that prompt the airbag warning light to illuminate.

As if this weren’t bad enough, exposure to environmental factors, temperature variations, and general usage further exacerbate the degradation of these components.

3. Malfunctioning Sensors

Defective seatbelt sensors can trigger the service airbag light by failing to detect seatbelt use. Crucial for passenger safety, these sensors relay information to the SRS or airbag control system. If they malfunction or encounter issues, the SRS may interpret the situation as a lack of seatbelt engagement, setting the warning light off.

Similarly, other sensors like the Passenger Seat Occupancy Sensor and Acceleration Sensors can also lead to an illuminated airbag light if compromised.

To prevent these critical sensors from having issues, avoid spills or debris in the seatbelt buckle, ensure the seatbelt is strapped securely when used, and conduct regular vehicle upkeep to spot and address issues promptly.

4. Software or System Glitch

Electronic systems in modern cars can occasionally experience glitches or software issues, causing the airbag light to come on. This glitch may originate from issues in the SRS control module software, where errors or bugs can occur.

Alternatively, malfunctions in the electronic communication systems between the sensors, modules, and the SRS control unit may disrupt the airbag system’s proper functioning. Such glitches can trigger a false reading, prompting the system to erroneously activate the service airbag light.

5. Airbag System Issues

We’ve established in the first five items in this list that issues with the airbag control module (responsible for deploying airbags) and sensors can lead to the airbag warning light illuminating. However, the latter can also result from factors beyond deteriorated components or accidents.

Complex interconnections of sensors, modules, and the airbag control unit may face disruptions due to corrosion, moisture, faulty airbag inflators, or sensor calibration errors. These factors compromise the system’s integrity, prompting the airbag warning light.

Fortunately, nuanced problems beyond typical wear and tear can be handled through regular maintenance and prompt airbag system diagnostics.

6. Charging System Problems

The airbag control module relies on a stable power supply for proper function. Charging system issues disrupt this supply, triggering the airbag warning light as a safety precaution. This ‘signal’ indicates potential complications in the airbag system’s responsiveness during an emergency.

In this scenario, erring components, such as the battery and alternator (view on Amazon), can activate the airbag warning light. If your vehicle’s battery is too weak or the alternator is malfunctioning, insufficient power may reach the airbag system, leading to irregularities.

7. Faulty or Non-Working Clock Springs

The clock spring is one of the most troublesome reasons behind an illuminated airbag warning light for a couple of reasons. Firstly, it requires a certain level of meticulousness and mechanical savvy. Secondly, it isn’t cheap to fix. According to Car Treatments and Youcanic, replacing a clock spring costs between $200 and $1,200 (this estimate is as of November 2023).

These drawbacks aside, the clock spring is vital to the optimal function of an airbag warning light. It maintains electrical connections while allowing the steering wheel to turn. Although not exclusive to the airbag system, when compromised, the clock spring can disrupt continuous electrical contact between components within the steering wheel.

8. Severe Temperature Conditions

Drastic temperatures — both hold and cold — impact the integrity of the airbag system’s sensors, modules, and wiring, causing them to malfunction. In extreme cold, these components may become rigid and brittle. Meanwhile, they may experience accelerated wear and degradation in intense heat.

These temperature-induced changes compromise the overall functionality of the airbag system, effectively triggering the airbag warning light for driver and passenger safety.

The rate at which severe temperatures affect the airbag system depends on various factors. These conditions include the vehicle’s age and the quality of its components.

In extreme cold, components may become more prone to malfunctions more quickly than in intense heat. Note, however, that there’s no specific timeframe for either, and symptoms may become noticeable gradually as the vehicle is repeatedly exposed to such conditions.

9. Human Error or Oversight

One of the more common triggers of an activated airbag light is the lack of human diligence. A good example is when people forget to fasten their seatbelts — an essential component of SRS. We can also add inaccurate use or non-use of seatbelts (and the passenger seat) to the list.

These unintentional lapses are inevitable, yes. Still, they’re enough to cause the airbag system to interpret the situation as a lack of seatbelt engagement.

However, car owners and passengers aren’t the only ones to blame. Oversight can also occur among professionals. Haphazard or incorrect installation of a replacement airbag and failure to double-check electrical components linked to the proper functioning of the airbag system also counts as human error.

10. Seatbelt Pretensioner Issues

Problems with the seatbelt pretensioner, designed to tighten the seatbelt in the event of a crash, can trigger the airbag light. Pretensioner aside, an improperly strapped seatbelt can also set off the airbag warning light.

In my article on resetting the airbag light, I highlighted that seemingly trivial items like spare change can get lodged inside the seatbelt buckle, impeding the sensors from recognizing when the seatbelt is in use. Spare change isn’t the only potential issue when assessing your seatbelt’s functionality.

Factors like liquid exposure, debris, electrical issues, physical damage, and normal wear and tear can also contribute to seatbelt pretensioner malfunction. Thankfully, regular inspection and proper maintenance can prevent such problems, ensuring the optimal function of your vehicle’s safety features.

11. Faulty Airbag Switch

A faulty airbag switch, often found in the passenger area, can activate the airbag warning light. This switch — which allows occupants to deactivate the passenger-side airbag — may malfunction due to internal issues or wear. When it fails to operate correctly, the SRS interprets the situation as a potential safety concern. Thus, it sets the airbag light off.

12. Defective Airbag

If all preceding items check out during diagnostics, then only one culprit remains — the airbag itself.

Several things can compromise an airbag’s safety mechanisms. These include manufacturing defects, inadequate deployment in a previous collision, or exposure to extreme environmental conditions. Airbags also degrade over time, causing issues with the inflator, sensors, or internal components.

Both driver-side and passenger-side airbags can experience malfunctions, and neither is inherently more prone than the other. Issue-generating factors affect both types of airbags similarly, making it crucial to promptly address any airbag warning lights.

Regarding resolving the matter, however, replacing driver-side airbags has proven easier than passenger airbags. The steering wheel’s straightforward design and accessibility make the process less labor-intensive. In contrast, passenger-side airbags are often integrated into the dashboard, requiring more intricate disassembly for replacement.

Regardless of which airbag is defective, replacing it isn’t a DIY task but a complex one that requires specialized knowledge and skills. Handling airbags involves safety considerations.

Improper installation can cause serious consequences, including injury or malfunction during deployment. Therefore, I recommend outsourcing the task to an experienced automotive professional.

Conclusion — Why Is My Airbag Light On?

Once more, here are the most common reasons why your airbag warning light is on:

1. Impact or Accident
2. Deteriorated Components
3. Malfunctioning Sensors
4. Software or System Glitch
5. Airbag System Issues
6. Charging System Problems
7. Faulty or Non-Working Clock Springs
8. Severe Temperature Conditions
9. Human Error or Oversight
10. Seatbelt Pretensioner Issues
11. Faulty Airbag Switch
12. Defective Airbag

Although non-exhaustive, the information in today’s guide should aptly answer the questions: “Why is my airbag light on?” and “What does the airbag light mean?”

Most of the reasons behind your illuminated warning light can be addressed through regular inspection and maintenance of the airbag system and relevant components. However, nothing beats the rewards of conscientious driving habits and proper vehicle use.