Weird sound coming from underneath my truck near the rear driver side tire

When I opened my garage this AM, I heard a mechanical sound in my garage tht I've never heard before. It was very subtle but audible. Much like the sound of a compressor with the volume turned down to barely audible. I walked around my truck and isolated the sound to underneath near the rear driver side tire(in the pic). There is a black box near the rear drivers side tire that the sound is coming from. Can anyone tell me what this box is?



I took a small video clip, but the *.MOV extension is not allowed here, which makes sense. It anyone wants to hear it, I uploaded the clip to my BOX account. You will need to turn up your your speakers. And if you do listen to it, realize I sound like a dumbfounded dufass with no caffeine at 5am this morning. https://mcafee.box.com/s/8pxbpzy6hy012w7bbacxzycffg3fqgpz

Lastly, right after I observed the sound, I started up the truck and then turned it off 10 seconds later. As soon as I turned off the truck, there was a similar sound that came from the same location, only this time, it was higher pitched and it stopped about 3-4 seconds upon turning off the truck.

I'm assuming it had been operating all night from the time I turned off my truck around 1030 pm. Either way, something was stuck and could have eventually drained the battery.

Clearly an electro-mechanical component of some sort. Perhaps a fuel pump component?

Thanks!

 

What is the normal duration for such a check? And what activates the check? (ie. engine startup, engine shutdown, etc..)

Near as I can tell, this was running all night (from 1030pm).

 

2017 Platinum Crewmax, brand new, picked up Saturday.

Again, this component was running when I walked into the garage at 5am this morning, after the truck was shutdown at 1030pm the night before.

And this AM, when i started the truck and then shut it down, the sound continued for about 3-5 seconds (at a higher pitch) and then went away. Based on the various posts from others, this behavior seems normal.

But the component/device running all night is not normal. Agreed?

 

I doubt it ran all night. IIRC it's set to start several hours (+- five?) after shut off.

 

@Cat3ILS I spoke with the service adviser to understand this a little more. And you are correct in that it was running all night. Apparently, there is a time based component for normal operations. When I walked out at 5am, it was pure coincidence that it had activated shortly before.

All good.. Thanks for the responses..