What Does SRS In A Car Mean (+Tips For Fixing)

what does srs in a car mean

So you have an SRS light on? And you wonder “What does SRS in a car mean?“. Well, let me tell you, it’s more important than you might think.

But first, imagine this scenario(or maybe you have already experienced it) – You are cruising on the highway, talking with friends, and suddenly the SRS light comes on your dashboard. What does that mean? Is it serious? Should I pull over?

Simply put, yes. It’s time to pull over. You have a problem with your SRS system, mostly known as your airbag system.


Oftentimes, it is possible to continue your journey with the SRS light on, but it’s not advisable to do it. At this point, your airbag system does not function properly and increases the risk of you getting hurt in a potential car accident.

That’s why today I am gonna dive deeply into the SRS system and why it is crucial for your safety.

Stay with me throughout this article to find out what SRS means, how it works, possible causes, and potential DIY fixes.

Let’s start.

What Does the SRS Light Mean?

SRS Light on car's dashboard
Red airbag light on car dashboard. 3D rendered illustration.

The SRS stands for Supplemental Restraint System, which includes parts of the car critical to your safety, like the airbags. Typically, you can find this in Mercedes vehicles, because the light that comes on your dashboard simply says SRS, while on most vehicles you will just get an airbag symbol”. It doesn’t matter which make and model you drive these two basically mean the same.

The Supplemental Restraint System (SRS) is the control unit that controls all of your airbags, seatbelts, and the position of the people in the passenger compartment. The SRS system’s main function is to ensure your safety and the people who travel with you. It’s completely passive and you don’t need to do anything in order for it to function.


How Does The SRS System Works?

As I’ve mentioned above typically, the vehicle’s SRS system is referred to as your airbag system, but it’s actually a bit more complex than that.

The SRS is a system that it’s designed to function like a network, between all the car’s safety features. This network connects all the sensors, modules, and wires that are responsible to keep you safe in a potential car crash.

Let’s share all the main functions of an SRS system:

  • Sensors: When a collision occurs, the SRS sensors detect the impact’s force.
  • Control Module: If the impact is severe enough, the sensors send a signal to the car’s SRS control module. This module, acting as the system’s brain, decides whether to deploy the airbags.
  • Airbag Inflator: If the situation calls for it, the control module will activate the airbag inflator. The inflator then fills the airbag with gas, causing it to deploy and cushion the passengers, reducing the risk of serious injury.
  • Seat Belt Pre-tensioner System: The SRS also includes the seat belt pre-tensioner system. In a crash, the pre-tensioners tighten the seat belts, pulling the occupants back into their seats and away from the airbags, maximizing the airbags’ effectiveness and minimizing potential injury.

Important Note: The seatbelts in your car are the first line of defense in a potential crash, while the SRS system is an additional layer of security. It’s important to know the difference and always wear your seatbelt to ensure that this system is working correctly at any given moment. 

The Role of the SRS in Different Types of Collisions

demonstration of an airbag SRS collision
Airbag exploded at a car accident

Now that you know how the SRS works, let’s find out how it operates in different types of collisions.

Typically the response of this system is tailored to the specific type of accident and its severity. This means that the system will provide targeted protection where it’s most needed. Especially in the newer vehicles the SRS system evolved and it can predict potential car accidents.

Let’s dive deeper into the most common types of collisions:

  • Frontal Collisions – These are the most common type of collisions and can result in severe injuries because of the high speed. The SRS sensors detect the sudden deceleration and, if the impact is severe enough, trigger the deployment of the front airbags.
  • Side Collisions – T-bone collisions are one of the most dangerous ones because you don’t have an engine in front of you and you are basically exposed to a direct hit. But here comes the SRS to protect just that. In these situations, side airbags play a crucial role. They deploy from the seat or door, protecting the occupants’ heads and upper bodies from hitting the door or window.
  • Rollover Accidents – Another super dangerous accidents are the rollover ones. Once again the sensors can detect that a rollover is happening and they deploy certain airbags to prevent you from injury. These airbags stay inflated longer to provide continued protection as the vehicle rolls.

There are many types of accidents, but these are the most common ones that should give you a basic idea of how the whole system works in different types of collisions.

How Has The SRS Improved Over Time?

After I’ve shared with you the basics of an SRS and how it operates, let’s find out how it all started and how it improved over time.

John W. Hetrick of Newport, Pennsylvania came up with the idea after an accident where he swerved the car in order to avoid hitting a rock where his daughter almost flew off the window. Later in 1952, he signed his patent for a Safety cushion assembly for automotive vehicles. While a German inventor named Walter Linderer signed the patent for airbags several months before Hetrick.


Now let’s cover the past, present, and future:

  • Past – The concept of an airbag, a key component of the SRS, dates back to the early 1950s. However, it wasn’t until the 1970s that airbags began to appear in production vehicles, primarily in the United States.
  • Present – Today’s SRS systems are far more complicated. They include not only front airbags but also side airbags, curtain airbags, knee airbags, and even seatbelt airbags in some models. 
  • Future – Looking ahead, the SRS system is set to become even more advanced. As autonomous vehicles become more common, SRS systems will need to adapt to different seating configurations and occupant behaviors.

Even now, we can pretty much say that we live in the future. Most modern vehicles are now equipped with advanced driver-assistance systems (ADAS) which use sensors, cameras, and radars to detect potential accidents. These systems notify the driver to keep closer attention to what’s going on.

Possible Causes of SRS Light On Your Dashboard

passenger airbag on light in a dashboard
Close-up Macro of the light in a new car stating that the airbag is on.

There are a lot of reasons that can trigger the SRS warning light or airbag light:

  • Battery Voltage – A drop in your battery voltage oftentimes can cause the SRS light. Oftentimes the SRS is equipped with a backup battery which is the main cause of the issue.
  • SRS Computer – Rarely the SRS computer may be faulty and it needs to be replaced because your airbags may not deploy in a potential accident.
  • Airbag Malfunction – As I’ve told you above, the airbags are connected to your SRS system and a malfunction in certain airbags can trigger this light.
  • Seatbelt Issues – The SRS system includes seatbelt pre-tensioners, which tighten the seatbelts in a crash to help protect to protect you from injury. A malfunction in any of your seatbelts will trigger the SRS warning light.
  • Accident – A past accident that didn’t trigger the airbags means that the SRS needs to be reset.
  • Wiring Issues – We’ve mentioned earlier that the SRS is a network connected with wires. Any corrosion or damage to these wires will certainly trigger the warning light.
  • Steering Wheel Sensor – Also called the clock spring maintains the connection of all the electrical components in your steering wheel which also includes the airbag, if this sensor is worn out it can cause the light to flash.

How to Fix the SRS Light

a mechanic fixing the SRS light

As car owners oftentimes we try to fix some things on our cars to save some money instead of paying for an expensive mechanic.

I will share with you some easy and possible fixes that you can try by yourself.

Check Your Battery

If there’s a drop in the voltage of your battery, you can hook up another car to your battery terminals and charge it. This way if a low voltage caused your SRS warning light you can fix it. Oftentimes you will need to “reset” it by removing one of the battery terminals, this can make the light go off.

Use An OBD2 Scanner To Reset It

Before you reset the SRS light with an OBD2 scanner it’s important to research which scanners can access this system. Not every tool is compatible with the SRS systems, that’s why it is important to choose the best possible scan tool to perform a reset.

In fact, the only useful OBD2 feature of Teslas is diagnosing SRS problems. Other than that OBD2 scanners are pretty useless in Teslas and most electric cars.

Inspect The Seatbelts

Often times the pre-tensioner system goes faulty and it’s most common for the front seat seatbelt because it is used daily. You can easily check if the pre-tensioner is working by pulling the seatbelt sharply which should activate the pre-tensioner. If you pull it and the seatbelt does not “lock” instantly this means that you have a problem.

A seatbelt pre-tensioner
A seatbelt pre-tensioner – Image Source

Here are some more easy fixes:

  • Inspect the Airbag Connectors
  • Turn on and off your ignition
  • Check the passenger airbag switch
  • Replace a broken clock spring

What Does SRS in a Car Mean FAQs 

How much does it cost to fix an SRS sensor?

The SRS system is very complicated and it’s often hard to say what will be the cost. Typically replacing an SRS sensor will cost you around 400$ depending on the vehicle you drive.

Is it safe to drive with an SRS light on?

SRS light does not affect your vehicle’s performance in any way and in that context, it’s absolutely safe to drive. However, this means that the safety system does not function properly and it’s far more dangerous to continue your journey. In other words, you should get it checked immediately.

What to do when the SRS light comes on?

Continue your journey with caution and get it checked as soon as possible by the closest workshop. It can be something simple like a low battery voltage, but you can’t be sure, that’s why keep your attention high and get it checked immediately.

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