Recall someone mentioned same. Noise u hear could be caused by "emission test" thats programmed to start about 5 hrs after shutdown, but only runs for very short time. Dont recall what test is actually for or why needed?

 

Yes it's from the emissions system, totally normal..

 

I have yet to catch it in action.

 

I caught it! But not sure how to post the video?

 

I've never caught it either but it is a thing. Ignore it.

 

I heard a loud buzzing sound when I went into the garage Friday night and thought it sounded like it was coming from the rear of the new HL. I went in to get my husband, but wouldn't you know it, the sound had already stopped when we went back out. I looked through the manual but couldn't figure out what it was.

Thanks for posting this question ... you solved the mystery for me!

I just did a quick search and found where somebody else had asked about it:

http://www.toyotanation.com/forum/3...eration-2014/1242386-buzzing-sound-coming-behind-right-rear-well-well-area.html

 

I heard a loud buzzing sound when I went into the garage Friday night and thought it sounded like it was coming from the rear of the new HL. I went in to get my husband, but wouldn't you know it, the sound had already stopped when we went back out. I looked through the manual but couldn't figure out what it was.

Thanks for posting this question ... you solved the mystery for me!

I just did a quick search and found where somebody else had asked about it:

Buzzing sound coming from behind right rear well well area

That humming noise you are hearing is the computers in your car updating! I owned 2 Lexus before my 2018 highlander platnum limited and they did exactly the same thing the toyota's do. The first time I heard it I was freaked out as well! Don't worry about it. It's completely normal. Jack.

 

We picked up a used 2014 Yaris SE a couple of months ago.
Last night heard the hum about 5 hours or so after it was put in the garage.
I was freaked out at first, but did a Google search to show that apparently this is "normal" for some automated emission test.

It is weird. How long does it last?

 

20-25 min.

 

Thanks!

 

"Approximately five hours after the engine is turned off, you may hear sound
coming from under the vehicle for several minutes. This is because the fuel
evaporation leakage check is performed. It does not indicate a malfunction."

 

Yep, scared the heck out of me when I heard it too.

 

"Approximately five hours after the engine is turned off, you may hear sound
coming from under the vehicle for several minutes. This is because the fuel
evaporation leakage check is performed. It does not indicate a malfunction."

 

I have a 2020 Toyota Corolla and hear a humming noise when walking by at 4am the next day. After 10hrs of driving the car been sitting on the drive way. I didn't touch or start the car at all, I notice it when I was only walking by.

 

Read this thread from the start. It is explained, and normal.

 

i remember being outside at night working on an older car and hearing the noise from the HL. I remember thinking; "what in the F...?"
after a quick google search, i remember shaking my head and being amazed at how different cars are now from what they were 20 years ago... so much has changed.

 

I have a 2020 Camry making the same noise. Page 8 of the owners' manual states "about 5 hours after shutting off a fuel evaporation leakage check is performed. This does not indicate a malfunction."

 

We just bought a 2023 Crown and just heard that sound in the garage. I guess it's the same as all the other reports above. Thanks for taking the time to let us know we are not crazy. :-]

 

POI…don’t top off the tank when refilling with gasoline. May ruin the Evap Canister…

 

I just filled up the tank yesterday for the first time since we bought it. I never "top off" when fulling up. I found some other folks have heard a sound about five hours after parking the car in the garage. They said it has something about a builtin test for the emission control under the back of the car.

 

That sound is the evap system being tested/purged. Nothing to worry and out.

 

I just heard it. I got concerned...that's why I'm here. Glad to hear it's normal.

 

Thankful for this thread! I’m about 2hrs from nearest dealership so just saved me a trip. I assume it’s the same sound discussed in this thread. I managed to get a good video of the sound and location. It’s on a 2024 Corolla Cross XLE. Here is the video link:—> March 31, 2024