Fuel pump running randomly?

I was just out walking my dog before bed, and on passing my truck I heard this vibration coming out of the drivers side rear wheel well. The truck had been parked for over 5 hours and has about 3/4 of fuel in the tank. I put the keys in and turned them to ignition (not crank) and the noise went away after everything set itself up for running. I’m a little concerned this would kill the battery if the truck sat for more than a a couple of weeks, not to mention understanding what it’s doing in the first place.

 

Evaporation system doing its thing.
Perfectly normal.

 

Thanks! These new trucks continue to surprise me with the systems they have installed.

 

Its more computer than truck btw.

 

Ain’t that the disturbing truth lol

 

This has been a feature on Tacoma's since 2005, you can imagine how many people its freaked out over the past 16 years.

 

Especially people that go camping and decide to sleep in the bed.

 

Yeah that would be a bit startling in the middle of the night, lol.

 

Come help me in this other thread..