Why is My Airbag Light On? Top 3 of the Most Common Causes

Why is my airbag light on? It could indicate the difference between life and death in case your car is involved in a car accident. Many drivers don’t put any effort to explore why a dashboard light is on.


But if you are anything like I am, you will not rest until you get to the bottom of the warning light in your dashboard; since it’s your car’s way of asking you to get your life in order.

Your airbag warning light is inarguably one of the most dangerous lights you can have illuminating your dashboard. Here’s how to troubleshoot and fix it.

1. Understanding The Airbag

Your airbag system consists of some sensors, a computer module that processes the data signals and a bag (of air) that is quickly inflated by a small charge in the bag. The sensors in your airbag system might wear out rendering them inoperative.

via mekshat.com

The passenger occupancy and the clock spring sensors are the two most common sensors that fail. The passenger occupancy is weight sensitive to ensure that you don't have more than the required weight on your front seat.

This sensor ensures that babies on the front seat don't get their airbags crashing on the infants head during an accident, but your adult buddies are guaranteed a bag of air to the face should things fall apart.

The airbag clock springs are found on your steering wheel. Its work is to ensure continuity of the electrical wiring with the driver's airbag. It does this by coiling itself in and out as the steering wheel turns.

2. Why is My Airbag Light On?

There are many different reasons that can cause your airbag light to flash or stay on. Just like troubleshooting your check engine light (get more details on how to reset check engine light here), fixing your airbag warning light can be challenging sometimes and should never be ignored.

All the same, the most important thing to know is that, an illuminated airbag light indicates a problem in the SRS system. This means that airbags might not deploy in the event of an accident. Here are the common reasons that cause your airbag light to illuminate;

1. Airbag Clock Spring Damage

After continued use, the thin circuit bands that make up your airbag clock spring may become brittle or worn out. This leads to a sporadic connection of your driver's airbag. If this is the case, the system will send a code to your computer and the airbag light will turn on or flash.

via wjjeeps.com

An obvious giveaway of a damaged Airbag Clock Spring is a broken horn and an airbag light (unless you have a bad fuse). You will have to remove your steering wheel to fix this one. Luckily, with the right tools, you will be done in under 30 minutes.

Make sure to buy the correct Airbag Clock Spring specific to your vehicle. Ensure that you disconnect the negative terminal of the battery and allow quarter an hour for the capacitors to discharge.

For a step by step guide to removing and replacing a damaged Airbag Clock Spring, check this Video on YouTube. The procedure may vary depending on your vehicle, but the concept is the same.

2. Passenger Occupancy Sensor Damage

via mbworld.org

Given that the passenger seats are adjustable, the wiring connecting the passenger occupancy sensor is vulnerable to getting stretched and frayed in the process. It can even get detached altogether.

via elesys-na.com

To determine if the sensor is working okay, first check the "Passenger Airbag Off" indicator. If the seat is vacant, this light should be on. When the seat is occupied it should turn off implying that the airbag system is online and functioning.

If the light is off when the seat is vacant or vice-versa, there could be a problem with the sensor. You will want to first check the wiring and harness underneath your seats to see if everything is connected. Ensure that no wire is frayed.

If everything seems okay, but you can't get the light to go off when the passenger seat is occupied, you can either replace the pad on your seat (expensive) or install a universal plug and play kit to bypass the occupancy sensor (only when you know you will not have kids in the front seat).

To install the universal kit; disconnect the yellow connector under the passenger seat and connect the kit. You need to get your wire splicing game up otherwise, you might end up with wires crossed -rendering the airbag system disarmed.

3. Airbag Backup Battery Depleted

The SRS system has a backup battery that steps in during a crash. This battery is charged by the main car battery. When the main battery discharges, the backup battery also discharges. This might cause the airbag light to appear.

As you might have guessed, charging or replacing the battery solves this problem and the airbag light will turn off. All the same, in some vehicle models, the light might not go off even after charging the battery. This is because the system already reported an error code. You will need a Scan-tool to delete the soft-code error that was sent to the airbag control module.

The above issues are the most common causes of an illuminated airbag light. However, not all airbag lights are caused by the said issues, but in most instances these are the components that will trigger the airbag light to be on.

If the above remedies don't work, you might want to reset your airbag system. This is a very delicate process and you might want to do it as a last resort. This process will clear and reset all warning lights and display the error codes.

3. Conclusion!

Avoid driving your car if the airbag light is on. Conduct a quick diagnostic by performing the following checks:

  • Charge your battery or replace a faulty battery.
  • Ensure that the passenger occupancy sensor is wired correctly.
  • Check your airbag clock spring (especially if you have a faulty horn).

Some airbag issues need professional hands to resolve. If you think your car is faulty and the above sensors seem to work fine, consult your mechanic/dealer. Otherwise, I wish you all the best as you try this simple DIY.

Leave a Comment: