2009 Toyota Matrix Intermittent Airbag/seatbelt Alarm Light

My 09 Matrix passenger seatbelt/Airbag Alarm light started to come off intermittently a few months ago. It often came off in a cold morning (when temperature dropps below 40F) after driving for 30+miles. I have taken it to a mechanics and they found an airbag code. They cleared the code but cannot find the root cause. I saw from some online forum that it happened to a lot 05 Matrix and repair involves replacing the clock assembly eventually. It seems to be odd since it only happened to me when it is cold and after some driving. I suspect that it has something to do with the battery since the battery output voltage may be the only thing I can think of that can be temperature dependant. Any help or comments from the community?

It could be one of the sensors in the seat belt buckle or the seat cushion, or the wiring or connectors to those sensors.

“I have taken it to a mechanics and they found an airbag code.”

“They cleared the code but cannot find the root cause.”

Independent mechanics ? Is this correct ?
I take it that this car is out of warranty ? Is this correct ?

This is probably one of those circumstances where a Toyota dealer and Toyota technician is your best option. Should they not be able to find a cause then they’ll need to call in some help, probably starting with the regional Toyota Service & Parts representative.

I would think that a problem involving a safety issue developing on one of their products does not give them the option of shrugging and say, “don’t know.”

You will be responsible for diagnostic labor, cost of a required part, and labor to replace the part or make a repair, if this vehicle is out of warranty.


The electronics control their own voltage. That said the control electronics are in the computer module along with their power/voltage regulators. Toyota may have a program for replacement if you qualify. Sometime cold temps cause bad joints on the circuit board due to the hard solders used to replace the more temp friendly lead solder. It is usually a bad run of modules and they will not do a public recall.

My 2009 has the same issue but i have not correlated it to the cold. My mechanic could not reset the light however, when I brought it to my dealer for a different recall notice, they turned it off without saying anything to me about it. (I took this to mean it wasn’t serious.) It came back on several miles down the road. I did call the dealer when it originally went on and was told it would cost me $98 “just to hook it up to the computer” Grrr…

There’s a recall on for earlier models of the same vehicle for the air bag. I’m waiting for the recall to be expanded to this year. In the meantime, I’ve told me family that if I should have an unexplained accident they should check to see if the airbag exploded before impact.

@Chillygator having worked at a dealership I can tell you this

Any dealer will charge approximately 1 hour labor just to hook up the scanner, retrieve codes, clear codes, etc.

Think about this scenario.

Your car gets in an accident

An airbag deploys

You repair the car yourself

But you can’t clear the light, because you don’t have a scanner capable of doing that

You bring it to the dealer

Why should they clear the light for free?