My air bag light (apparently) burnt out. It used to cycle when I turned on the ignition, now it does nothing. I suppose the obvious first step is to ensure the bulb is good...is this bulb accessible through the rear of the cluster, or is it one of those surface mount-on circuit board type?

Thanks!

 

Bring it to the dealer to make sure it isn't a real air bag problem first... Might cost you a diagnostics fee but it's worth knowing you're safe.

 

Yes, it is.

 

The light is fail-safe on...if there is a problem in the SRS system, it will turn the bulb on. Since it doesnt come on, on "ign on" checking the bulb first BEFORE going to the stealership only makes since. I mean, why would you diagnose a system, without a working indicator first??

 

Thanks NTtech, but just to clarify...are you sure about that on my 2005?

I just dont want to tear out my dashboard before knowing for sure.

 

B/c those bulbs are rated for like 25,000 hours which is equivalent to 500,000 miles if you do a direct comparison....

Not saying it might not be a fluke but making sure the system is indeed working is important...

The light you see when you turn the vehicle on is actually the system testing itself, so if it isn't coming on it could mean that it is not testing itself.

Not saying it isn't or couldn't be a bulb, but I'm a better to be safe than sorry type of person.

 

Totally the right approach. In his case though with the cluster, he won't be in any danger of crossing paths with the Airbag system. The engineers did something right when they islolated and color coded the Airbag circuits for dummies like me who pry, yank and stab at things Sometimes I even throw rocks at it

 

First, I dont know where you get 25,000 hours longevity on that bulb. If its an incandescent, I know its MUCH less than that. And things like voltage spikes and impacts can effect their life too.

And I did do your math, but your are confusing whether the bulb is on during that time, in fact, if the system is normal (bulb out), that number should be higher.

I think your missing the point. The REASON for a fail-safe light, is to let you know that there IS a problem with the system. If you know that light is not working, why would you check the system first? Thats like replacing your oil pump when you oil pressure light is not on when the engine is not running.

It doesnt matter how or why the system lights this bulb, it is doing it for the only reason to show you the bulb is good, so again, the easiest and most logical step is to confirm the bulb id good.

I understand, and Im not trying to be argumentative, and I do want my SRS system to be working correctly, but if the bulb isnt illuminating at start up as it should, Im going to start at the bulb. It only makes sense.

 

Okay let me just educate you a little bit on why that light turns on when you start the vehicle.

When you start the vehicle the light turns on for 5-20 seconds depending on the air bag system that is present.

During that time it performs a "SELF-CHECK" which basically checks to make sure the system's sensors are responding.

Here is a little link to some reading material on this: http://www.airbagsolutions.com/light.aspx

So if the light isn't burnt out (which is possible but not very likely) then it is not performing the self-check.

I'm not trying to stop you from checking the bulb that is your choice, I'm just saying I'd get it scanned real quick at my dealer or a local Auto Body shop that has a DRB III tool to pull the codes (if any).

I'm an MECP certified technician so electrical systems is what I did for a long time, mostly mobile electronics installs, but I did troubleshooting for some Auto Manufacturers at the end of my college education on electrical and warranty issues.

Also I hit the #2 instead of #1 so excuse my typo:

15,000 hours is the expected life span for the air bag bulbs. I translated that into miles based on average daily use (key cycles) a vehicle would see on average and multiplied by it's age... came up with close to 500,000 miles. (I rounded)

I'm not gonna argue with you, my time is more expensive than the diagnostics fee at the dealer and taking the cluster out is a pain in the @$$... most autobody shops won't even charge you to come out and hook up the scanner to test the SRS/Air Bag system so do what you want man.

I hope it's just a bulb... but I've seen plenty of vehicles have issues with the air bag system (usually if they have a passenger on/off switch) not run through the self-test cycle at startup, and no light comes on b/c it doesn't pick up any issues with the system.

That will usually be grounds for your scanner to either pick up an error code, OR it will show a "no connectivity" message meaning that the circuit is not complete, but the system doesn't see an error, which does happen more often than a bulb going out in the cluster.

Good Luck and Happy Hunting

Edit:

Just to illustrate my point here are some other threads of air bag light not coming on at start-up.

 

I have a scan tool...no codes.

Then you should know the SRS system is completely separate from the ECM system, so even if there is a fault in the SRS system, it would not throw a code.

Ive had the cluster out...took me maybe 15 minutes.

Thanks for your opinions.