What is this? Humming by the spare tire.

Haven't driven my truck in 5-6 hours probably but when I walked by it tonight I heard humming like an electric motor or something coming from under the truck. It was coming from this (see picture)

I put the key in the ignition and turned to on position (not started) and it stopped. Started the truck and then turned off the truck and nothing. Any ideas? Truck only has 1400 miles on it, so I'm not thrilled.

 

It's your evap pump on your fuel system. Relieved pressure on the system after you shut the truck off. Common on all our trucks

 

Normal. Some part of the evap system running a test if I recall correctly.

 

https://www.tacomaworld.com/threads/buzzing-humming-noise-from-under-bed.474064/

 

See this is why I posted this here lol.... Y'all are great! Thank you!

 

Bla, bla bla bla. I can’t believe they all told you so soon what it was! Bunch of losers ruined a great gag.