Here are some of the most common causes:
* Faulty Crash Sensor: These sensors detect impact and trigger airbag deployment. A malfunctioning sensor can send a false signal, triggering the light.
* Low Voltage: A weak battery or faulty charging system can cause the light to illuminate. The system needs sufficient power to operate correctly.
* Faulty Airbag Control Module (ACM): This is the "brain" of the system. A failing ACM is a common reason for the light to stay on. This is often a costly repair.
* Faulty Airbag(s): A problem with the airbag itself (e.g., a short, a damaged component) can trigger the light.
* Faulty Wiring or Connectors: Corrosion, damage, or loose connections in the wiring harness can disrupt the system. This is relatively common, particularly in older vehicles.
* Faulty Clock Spring: This is a spiral cable in the steering wheel that allows for steering wheel rotation while maintaining electrical contact for the airbag and horn. A broken clock spring is a frequent culprit.
* Seatbelt Pretensioner Malfunction: The pretensioners are designed to pull the seatbelts tight in a crash. A problem with these can illuminate the light.
* Passenger Sensor Malfunction (if equipped): Some vehicles have occupancy sensors to determine if a passenger is in the front seat before deploying the passenger-side airbag. A faulty sensor will trigger the light.
A mechanic will use a specialized scan tool to read diagnostic trouble codes (DTCs) from the airbag control module. These codes pinpoint the specific problem, leading to a more accurate and efficient repair. Ignoring the light is dangerous and could mean your airbags won't deploy in an accident.
