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SRS Light / Airbag Light - Why It's On and What It Means

The SRS light - or airbag light - is a warning light that alerts the driver to a problem with the supplemental restraint system (SRS). This computerized system is responsible for deploying airbags as well as tightening the seat belts to keep passengers properly restrained in the event of an impact.

The SRS light will be on your dashboard. It usually looks something like this:

What to do when the SRS light turns on

When the vehicle is first started, the SRS light should illuminate for 1 to 5 seconds while the system goes through a self-test sequence. If the light then goes out, the system is ready and safe to drive.

If the SRS light turns on while driving, or stays lit after starting up, it's best to take the vehicle to a repair shop as soon as possible to be properly diagnosed and inspected. The light could indicate a fault somewhere in the SRS system causing it to disable. In this scenario, airbags may not deploy and the seat belts may not tighten in the event of a collision.

You may also want to check for any airbag or SRS-related recall notices on your vehicle. Some repairs may be covered under a recall or extended warranty.

Why is the SRS light on?

The SRS light will come on anytime something in the supplemental restraint system - airbags, seat belts, or the computer and wiring that controls the system. Due to the importance of this system in protecting passengers from injury, all of these possible causes have the potential to be life-threatening.

However, there are a few simple things that could cause the SRS light to illuminate without a major fault in the system itself. For example:

  • Something (like a coin) interfering with the seat belt switch that determines whether or not it is correctly fastened.
  • Something under the seat interfering with the wiring.

Driving with the SRS warning light on

If the SRS light is blinking or stays on longer than a few seconds, take it seriously. While the car is still technically drive-able, the vehicle's safety systems could be compromised, putting you and your passengers at severe risk in an accident.

Another factor to consider is that auto insurance companies may reduce their coverage of medical bills from an accident if they determine that the airbag system was disabled at the time, indicated to the driver by the SRS light, and would have prevented the injuries if in full working condition. The SRS system contains a "black box" very much like a commercial airplane. It records the data from an accident such as the speed, "G" forces, and how many seat belts were latched. It also records how long the SRS system was disabled.

More about the supplemental restraint system (SRS)

The SRS computer continuously evaluates the input data sent to it by motion or "G" sensors, vehicle speed sensors, steering system sensors, vehicle angle sensors, and seat belt sensors. When the enabling criteria have been met - such as a vehicle speed above 25 MPH and a highly abnormal rate of deceleration - the SRS system will choose which, if any, airbags to deploy and which seat belts to pull tight. The purpose of the airbags is to cushion or prevent the vehicle occupants from hitting and slamming their body parts, especially the head, into the steering wheel or dashboard. The seat belts tighten in order to restrict the forward movement of the vehicle occupants.

Newer, more enhanced SRS systems recline the front seat backs, lowering the driver and passenger into a prone position to better absorb the whiplash/recoil phase of a collision and hopefully prevent any neck or spinal injury.  Many newer vehicles have side airbags to protect the vehicle occupants from hitting the side pillars, especially with their heads. Some new vehicles also have SRS curtains that come down to protect the occupants from breaking glass from windshields and windows.

The SRS system is also referred to as a passive restraint system because the vehicle occupants do not need to do anything in order to activate the SRS system when the enabling criteria - speed and deceleration - are met. In contrast, seat belts are an active restraint system. The vehicle occupants must proactively latch each seat belt in order for the seat belt to do its job. Even automatic seat belt systems have a lap belt that must be manually latched.

1 User Comment

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RE: SRS warning light flashing; I had this problem intermittently for YEARS. The dealership had no answer and no log file was left. Several months ago the light flashed and kept flashing. I looked at the seat belt connectors, took off covers, wiggled wires, etc and it kept flashing until I attempted to take out the light bulb. I took the cover off the lower dash, above the pedals, and saw I could not access the bulb. There was some sort of sensor attached to the cover. Lo and behold, when I replaced the cover, the light had stopped flashing! I wish I knew why, but it did!