Sound coming from Taco, while shut off!

OK, I have a new 2018 Offroad which what sounded like to me was the fuel pump running while the engine was shut off. I had used the truck earlier in the day, when I came out to the garage a few hours later I could hear a buzzing/humming sound coming from up under the rear wheel well. I jumped in and turned the truck on for a few seconds and then shut it off. The sound was not there after this "reset".

I was seconds away from heading off on a two week trip with another vehicle. I wonder if I would have returned to a dead battery? ANyone else having this problem?

 

It's not a problem, this is a normal function of the truck.

 

Not a problem. Emissions control system.

 

Oh,..I see, so this is a feature of the Tacoma?

 

It’s the emission system keeping fuel vapors from getting out. Happiness after a few hrs on all the trucks

 

OK, thank you for all the quick responses.

 

Enjoy your trip. The taco will be there when you get home

 

Yup normal. Haven’t heard it on my taco yet but have heard it on my other car at times