Piercing noise from Prius (maybe)

[Joannerice]

I was stopped in a line of traffic, waiting for the light to change. I reached over to pick something out of a bag on the passenger floor and got a piercing noise that appeared to be coming from under the glove compartment. It sounded just like a fire detector alarm going off--it was that piercing. I didn't know what to do. After about 30 seconds, the sound gradually wound down and disappeared. It has not happened since. I had the key fob in my jean pocket and wonder if I set off the alarm by bending over to pick up the bag. I have never tried the alarm button on the fob so I don't know what it sounds like. It doesn't work now when I press it. I can't think of anything I had in the car to sound like a home fire detector sound. The bag had a calendar, pocket calendar, and mouse pad.

Any ideas? What does the alarm on the key sound like? Is it honking?

[alanh]

Does your A/C work? The only think I can think of is a refrigerant leak.

[Joannerice]

Well, to be honest, I have not really had to use the A/C for a while. I will try it tomorrow.

As an aside, shouldn't car alarm when I press that red button on the FOB?

[McShadowManager]

Have any trouble with your brakes lately? Their is an alarm under the dash that makes a shrill noise when there is a serious problem with the braking system. Just something that came to mind...

[Joannerice]

I haven't noticed any problem with the brakes, although I did see the traction icon come on briefly when I didn't think it should yesterday. I will check the brakes out more thoroughly. I may end up taking it to the dealer, as it really did sound like I had a fire detector in the car. I appreciate all the suggestions.

[richard schumacher]

Were you moving again with traffic as the sound faded away?

When you press the red button on the fob for more than 3 seconds the car's horn should start to sound repeatedly, until you press the button again. Assume the position you were in and try it. Then turn the car ON (leave it in "Park", of course, with the brake set) and try it again (I don't know if it acts the same way with the car ON, but surely something should happen).

[Joannerice]

Actually I remembered a little more, though I don't know if it will help pinpoint the noise. At first, I thought I had hit the underside of the glove compartment when the noise started. The CD player was going, so I shut that off. Then I shut the car off. Nothing seemed to make a difference. It still shrilled with the car off. I then turned the car back on. The noise had already started descending before I moved forward in traffic. Nothing else sounded any different. Just this noise. The air conditioner works fine, the brakes work fine. It has not happened since.

Tomorrow I will go out and try repeating everything, car on, stopped, reaching over to the passenger floor.

I spoke to a Toyota dealer yesteday afternoon. They told me they had one other person report something similar, but they couldn't reproduce it so they didn't know what caused it.

It was scary.

P.S. I didn't know you had to press the FOB for 3 seconds to get the panic button to engage. I will try that, too, tomorrow.

[richard schumacher]

I have to wonder whether it was coming from another car near you. In any case it's hard to diagnose unless it happens again.

[Joannerice]

I've done a search on Prius Chat and the answer is still not clear to me. Is the "airbag" light always on, on the passenger side? For some reason, I never really noticed it until yesterday. When I reached down, I thought I may have hit something underneath the glove compartment. Could it have been some sensor I hit and the noise was a warning? The noise was definitely coming from inside the car. In my father's Buick, the airbag light came on and it was a problem with the computer which had to be replaced.

[Bill Merchant]

There's a light in front of the passenger seat that comes on and says AIRBAG when the car is running. If a passenger that weighs more than 50 pounds (I think, but this is variable) is sitting in the seat, another light comes on that says ON. This tells the passenger that the airbag is on, and just to be sure it's clear, the word PASSENGER is printed on the plastic above the lights.

I have no idea about the noise.