Mystery Buzzing Noise - Engine Off

I went to the garage and heard this buzzing near the rear - engine has been off for 4 hours. I turned it on, and back off and buzzing stopped. Any ideas?

https://youtube.com/shorts/h7RuSH_c9_8?si=yBv_rgYsCxUgtnPL

 

Perfectly normal, it's the evaporative emissions system/fuel system performing it's leak down test.

You can find several topics on the forums discussing this.

 

fixed it for you lol!

 

Welcome to the forum from North Carolina.
Usually comes on four to six hours after shutting the vehicle down. This is covered in the owners manual also

 

Thank you all!

 

Interesting. I’ve never heard my 2022 doing that. I’ve had it for 1 year and 2 months. I guess I’ve just never been around it yet when it’s doing that?

So what happens if it “fails” this “test”? Runability problems? Check engine light? Trouble code?

Is it covered under the emissions system warranty?

 

No mystery at all and mentioned in the manual. Self EVAP test.

 

Thanks for this!!!
When sleeping in 4runner wondered what wa sound/going on.

thanks