Seeing that airbag light illuminate in your dash can strike immediate fear to any driver. Will they fail do deploy when you need them most? Or will the airbags unexpectedly deploy while driving?
In many cases, a vehicle’s supplemental restraint system (SRS) light only signals a minor issue, even though we’ve been trained to equate any airbag problem with certain doom. Keep reading to learn the 5 most common reasons your airbag light comes on as well as the minimum speed needed for them to deploy.
Common Causes of the Airbag Light Coming On
1) Electrical Issues
The individual components of an airbag system are quite intricate. Problems with the airbag wiring harness, connections, couplers or power supply can disable airbags. Frayed, damaged, or loose wires create openings allowing shorts.
Intermittent warning lights point to wires or couplers vibrating free during driving. Check wire harnesses for damage. Bad grounds or voltage drops from aged car batteries also cause electrical trouble.
See Also: 5 Causes of the ‘Car With Lock Symbol” Light On
2) Seat Belt Issue
In some cases, not putting on your seat belt could cause the airbag light to come on. But there could be other seat belt issues that may cause this light to come on as well.
Perhaps your seat belt doesn’t snap securely into the buckle and stay in place. Maybe there is a problem with the sensors in the buckle and they don’t accurately tell the computer that you have fastened your seat belt.
Alternatively, there could be a problem with a seat belt pre-tensioner that may need to be repaired or replaced (especially if the vehicle’s been in a previous accident.
3) Damaged Sensors
It is possible to get into a small car accident (aka fender bender) that doesn’t deploy your airbags, but causes damage to at least one sensor. This typically occurs where the minimum speed for airbag deployment is not reached (see section below).
Crash sensors mounted in the front, side pillars, doors, and seats detect sudden deceleration signaling a collision. If damage or malfunctions occur, sensor trouble codes set off the warning light. Front sensor issues are most common, caused by hits to the bumper or wheel areas that jolt sensors.
4) Water Damage
If the internal components of your vehicle have water damage for whatever reason, then corrosion may form on the crash sensors of your airbag system.
This corrosion will distort their ability to function properly and it could result in the airbag light coming on.
5) Airbag System Not Reset
Once you’re in an accident which causes the airbags to deploy, simply replacing the airbag is not enough. Crash sensors, clock spring, seat belt pretensioners, and other SRS components must also be replaced. In addition, the airbag monitoring unit (the brains of the airbag system) will need to be reset or reprogrammed.
You will need to have a qualified mechanic or dealership reset/reprogram the SRS module so the airbag system can be used again. Alternatively, some companies allow you to ship them the airbag monitoring unit, they reset it for a fee, and then ship it back to you ready to install.
6) Blown Fuse
Each airbag component on the circuit gets power running through a specifically designated fuse. An overcurrent event from a short or spike in the system can blow this fuse cutting off power flow. Warning lights alert of lost power caused by a spent fuse needing replacement.
7) Defective SRS Module
As the brains of the airbag system, the SRS module constantly checks the status of components and sensors. If the module itself fails due to an internal error, water damage, or other cause, crash data inputs can fail to deploy airbags as needed.
In cases of a module malfunction, the airbag light may come on even when the rest of the system is completely functional.
See Also: Average Airbag Replacement Costs
Minimum Speed for Airbag Deployment
Airbags are designed for deployment when the front (or near front) of your vehicle collides with another vehicle or solid barrier. However, in order for the airbags to deploy, the minimum speed that you need to be driving during your collision is between 8 mph and 14 mph.
Most people are driving way above these speeds when they crash, usually between 35 mph and 60 mph. The faster you’re going during a collision, the more that you’ll need an airbag to save your life.
Diagnosing Airbag Issues
When the airbag warning light turns on, pinpointing the exact cause requires methodical diagnosis testing. Different options exist:
- OBDII Code Reader: The onboard diagnostics system stores trouble codes which point to certain components setting the light off, though codes do not always provide the full picture. Use an OBDII scan tool (with SRS capabilities) to access stored codes and then cross-reference with possible causes.
- Voltage Testing: An electrical system issue can disable airbags without setting codes. Test wiring harness, connectors, sensors and module voltage levels for drops showing breaks in power flow. This determines if replacement parts or wire repairs need addressing instead of just coded components.
- Visual Inspections: Damaged wiring harnesses, obviously disconnected sensors, corrosion in connectors can often be spotted through careful visual and physical checks before replacing correctly showing components. Look for points where electrical faults could occur like wear, crimps, or dirt buildup.
Without proper diagnostic testing, airbag repairs prove wasted if not addressing the root failure, exemplified by the light turning back on shortly after. Inspect stored codes but also follow through with thorough supplementary troubleshooting before assuming part replacements or resets.
Resetting the Airbag Light After Repairs
Once the underlying airbag system faults are successfully diagnosed and repaired/replaced, the airbag warning light needs to be reset to clear the trouble code memory and turn the light off.
Key Cycling
After completing repairs, turning the key into the “on” position for 30 seconds without cranking the engine allows the airbag diagnostic module to run through its self-check cycle. It resets status codes in the process.
Repeat this key on-off cycle procedure multiple times until the airbag warning light shuts off. Letting the vehicle sit for several minutes between cycles allows systems to power down completely each time.
Scan Tool Code Reset
The same OBD diagnostic scanners used to initially read stored trouble codes from airbag modules can also perform resets on most vehicles, turning the warning light off in the process.
This coded reset should only be done after correcting the flagged issues first or the trouble code(s) and subsequent airbag light will simply retrigger.
Manufacturer Specified Procedures
Some vehicle manufacturers designate their own specific steps for resetting airbag module warning lights separate from generic OBD scanners. Often part of an overall sensor or computer reset, this may entail intricate sequences of ignition or shift lever movements.
Always reference the exact make/model service manual for reset procedures before assuming only an OBD2 scan tool will work.
Verifying Light Stays Off
After performing resets using various methods, further road testing should follow. Drive the car through several full drive cycles allowing the airbag system’s self-diagnostics to run completely to check for fault code retriggers. Only if the dashboard warnings stay off continuously can the repair be verified as fully resolved.
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Hi, I had not driven my 2009 Chevy Impala LTZ for 3 days (58,432 miles) when the service airbag light & message came on. The car was still parked. I noticed the warning sometime after I had lifted the rear seats to check out the storage compartment I just read about that are beneath them. I also folded down the rear seat backs for the first time. After using a small low powered handheld personal car vac, that was plugged into the 12V outlet located inside the center armrest compartment, to clean the area, I did place a few items in the storage area. I’ve only owned the car for less than 3 months and am still learning my way around it. I later removed the items thinking that maybe the seats were not flush, but the airbag light has remained on. I also checked the seat backs multiple times to make sure they are securely back in place. The car has not been in any accidents. I had it fully inspected before purchasing it from an elderly relative. Any suggestions will be greatly appreciated. Thanks
I have a 2013 tundra that has never been in an accident when the the air bag light came on. Took it to a Toyota dealer who found that some little critter chomped un the ECM wiring. After replacing the wiring they tell me the ECM is not passing a signal and say the the module needs to be replaced at cost of about $1K including labor. What related event could require this?
It could be more bad wiring somewhere. If there was a little critter in the truck, I wouldn’t be surprised if there was still a bad connection somewhere.
My new wagon r I have purchase before 1year. Suddenly ignition switch on of my vehicle airbeg light open. Why?
So my airbag light has been on for about a month and it turns off and on every now and then. So far it’s been on for a whole week but turns off when I drive more than 60mph. What does that mean? Any guess what it could be and what needs to be replaced?
Thanks!
There should be a stored code that will tell you which component is faulty. I recommend you scan this code and then take it from there.
I didn’t notice but my shirt got caught caught in the seat belt where it clicks into place. Released the belt and now the airbag light is on. What the heck. Is it possible I damaged something or hopefully just a reset. Ever hear of this happening?
Nope, I’ve never heard of that happening. You can get that airbag light scanned though. There should be a code stored just like a standard check engine light. That should give you a better idea about what’s going on.
I have a 2008 Toyota yaris. The airbag light comes on everytime I push the gas pedal then off when I quit pushing the gas and take the car out of gear
How strange. What happens when you push the gas pedal in neutral? Does the airbag light come on?
I wonder if the acceleration could be tipping the vehicle a bit and messing with a bad airbag connection under the seat, for instance.
My mechanic is telling me the airbag light is on because the passenger seat belt retractor assembly is failing. From researching, it seems like this could be the cause. Will the driver’s airbag still work even if the airbag light is on or does this cause the whole airbag system to be disabled?
I’m not qualified to answer that. You may be able to find this information in your vehicle’s factory service manual, but I wouldn’t take a chance. It’s best to get the SRS system fixed as soon as possible.
I have a 2016 Chrysler 200 and the airbag light was on for two days and now it is off. I recently took it back to the dealership to have them service the airbag because the light stayed on. Now two weeks later it came on and then went off. What could be the cause of this?
It could be an issue with one of the electrical connectors for the airbag, such as under the seat. Scan the airbag code and that’ll give you a clue what the root cause is.
Had airbag replaced due to recall, and within a few months the airbag light was on (it never was prior to the replacement). Months later, In order to pass state inspection the light could not be on, but the fix was $2,600 to replace sensors under the driver seat. What a rip off – there will always be someone in the driver seat if the car is moving, so those airbags should always go off. Why do there even need to be sensors!
My car was recalled by Nissan last year because of a faulty airbag. No issues prior to than and none since but now the airbag light is on again. Can I presume this is another airbag issue as I have not done anything to affect this.
Get the code scanned, it may be related.
2001 Honda Accord airbag light stayed on. Took it to a mechanic they looked at it and said that it was the sensors. Noting that one could not be replaced without the other meaning the passenger and driver side. The cost was about $800. The mechanic felt like this was just a coincidence and reset it and said if it comes on again then they may have to replace it. It has been about three weeks and the light has not come back on. Do you think we’re OK now? And do you think it might be just a fluke as well?
Hard to say. If the light doesn’t come back you’re probably good, but it depends on what the original fault was for and what the root cause was.
Believe it or not, I recently learned that the airbag light problem could also be related to a wheel bearing problem. Try googling it.
Should there be concern if the airbag warning light turns on and then turns off while driving. the warning states airbags need servicing. the car is a 2016 Mitsubishi Outlander GT. This happened after the suv was not started for 2 weeks, it has only 24k miles on it and never had an accident.
The airbag code is probably stored in the computer’s memory. I would go to an auto parts store and see if they can read the code. They should be able to do this for free, and will give you a better idea of where the fault is occurring.
One thing you could do is to try to replicate the issue and trigger the code again. With the car running, try turning the steering wheel lock to lock. Does the light turn on at any point when you turn the steering wheel? If so, you may have a problem with your clock spring. These are relatively cheap and easy to replace.
Sometimes there are airbag connectors under the seat that can become dirty or corroded over time. You may be able to solve this by simply unplugging the connector and cleaning it. Before attempting this, follow your manufacturer’s recommendations for servicing the airbag system. These instructions can be found in the factory manual. At the very least, unplug the battery and wait 10 mins so there is no risk of the airbag going off. If you are not comfortable doing this, take your car to a mechanic for the repair.
HI
The key is stack in the ignition of a Chevrolet Trailblazer. The battery is fully charged, what will be the cause
Check to make sure the vehicle is in park. Many automatics won’t release the key from the ignition while the vehicle is in gear.
May granddaughter put a heavy suitcase in the passenger side of the Jeep. After I dropped her off at the train station and started the Jeep that’s when the airbag light come on. Could that be the cause?
A suitcase shouldn’t have affected anything unless it somehow caused an issue with the weight sensor or seat belt harness (ie: the suitcase was dropped HARD on the seat). They sensor may have been damaged or a wire loosened somewhere. To confirm the issue, use an OBD2 scanner that has SRS capabilities to see where the problem lies.