WHY IS MY SRS LIGHT / AIRBAG LIGHT ON?: HERE'S WHAT TO DO

Say you're driving down the road when, suddenly, the SRS warning light on your vehicle pops on. Does this spell big trouble? Do you know what you should do?

Do you even know what it means?!

In this post, we tell you what to do when the SRS light or airbag light is on in your car. First, we answer the important question:

What is the SRS warning light?

The supplemental restraint system (SRS) warning light is used to indicate a problem in the air bag system. Some instrument clusters display an image of a stick figure and an airbag to indicate an SRS concern. Others simply show the letters SRS.

Why is the term SRS used to describe the air bag system? Decades ago, when air bags were first introduced, automakers considered them a potential replacement for seatbelts. As the technology progressed, however, the industry realized air bags work better as a "supplement" to traditional restraints (i.e., seatbelts). And the term supplemental restraint system was born.

What does it mean when the SRS warning light stays on?

When you turn the ignition key to the "ON" position, the SRS light should come on momentarily, then extinguish. If the SRS light stays on, there's a problem with the system and the air bags may not deploy in the event of a crash. You'll want to seek professional diagnosis and repair as soon as possible.

Warning: You should never attempt to diagnose or repair an airbag system yourself. Accidental deployment can cause vehicle damage and severe personal injury. Any repairs must be handled by a professional. You can't learn this stuff by watching auto repair videos on YouTube, so it's best to leave the work to the repair shop.

How does the SRS system work?

To better comprehend the SRS light, it helps to have a basic understanding of the airbag system. Although designs vary by vehicle, a few key components are shared across the board. Keep in mind, these parts often go by different names, depending on the automaker.

• • Air bag module (s): A module that contains the air bag itself and the inflator assembly. Most cars have several airbags these days and, therefore, have several of these modules.

• • Clockspring: A cable that allows the steering wheel to turn without breaking electrical contact with the air bag module.

• • SRS module: The computer that governs the air bag system.

• • Air bag sensors: There are usually multiple sensors that measure conditions to identify a crash scenario.

In the case of an accident, the air bag sensors will relay a crash situation to the SRS module. The unit will then deploy the air bags.

Modern SRS systems are far more complex than the description above (and contain many more components). But that gives you a basic idea of operation.

What causes the SRS light to stay on?

The SRS module is the focal point of the air bag system. Often, the unit may go by other names as well. For example, it may be called the restraints control module (RCM) or sensing diagnostic module (SDM).

Regardless of what it's called, the module always has the same primary function: monitoring the air bag system. If the unit detects a problem, it will turn on the SRS warning light and store a corresponding diagnostic trouble code in its memory. The module may also disable the air bag system until the problem is fixed.

How do you reset the SRS light?

It should be noted that turning off the airbag warning light will not fix any problems. Instead, the action merely extinguishes the warning temporarily until any concerns are addressed. Only reset the light after the necessary repairs have been completed.

A professional can turn off the light (and clear the corresponding trouble codes) with an OEM-level scan tool. Generic scanners and code readers do not have the capability.

How much does it cost to fix the SRS light?

SRS light repair costs vary a great deal. The warning could be triggered by something as simple as a seat belt switch (the SRS module monitors those as well) to something as pricey as a failed air bag assembly. In other words, you could be looking at hundreds of dollars or thousands of dollars in auto repair, depending on what your mechanic finds.

How much does it cost to replace the air bag sensor?

Modern SRS systems often contain an array of sensors. Though when someone refers to the "air bag sensor", they're usually talking about the crash sensor (aka impact sensor).

Crash sensor replacement cost is all over the board as well. As a rule of thumb, expect to pay anywhere from a few hundred dollars to nearly a thousand dollars, depending on the type of car you have.

Also, remember, an SRS light doesn't necessarily indicate a bad air bag sensor. There are countless potential reasons for the illuminated warning. Have a professional properly diagnose your vehicle to determine the root cause.