Driving home from Colorado I heard a slight "ringing" sound that varied in loudness. Checked the doors, windows, tailgate, etc. It stopped and started a few seconds later, even with the ignition off. It went off and while driving through Texas I heard a slight "ring" or "whistle" each time I hit the brakes when the vehicle took a nose dive. I heard it a few times when the vehicle leaned to the left on a hard right turn. Have been home several days and have not heard it again. No lights came on and no fluid leaks under the car (2010, 4 Runner Trail). What kind of alarm would go off when the ignition is turned off? It was more like a "ringing" alarm, not a "dinging" alarm like a door adjar. Anyone have a suggestion?

Look under the car for something loose that might be rattling around whenever you brake.

Also, check to see if you might have something under the seat or in the console that could be moving.

I had a pen that was rattling around under the seat and made a "bing" noise whenever I braked.