Hey, all.

Saturday afternoon, I opened the passenger rear door of my 2019 TRDOR to get something. Closed it, went to the other back door and opened it, and I could hear a faint hum inside, toward the rear of the truck. Got in and closed the door, and it continued for about 2 minutes. Sounded like it was coming from the liftgate. I was able to record it, but it's too big to post here. I would estimate the sound at around 40-50 hertz, a bit lower-pitched than a 60 hertz AC current hum. Maybe a tiny bit louder toward the passenger side.

The vehicle hadn't been started that day, the key was not in the ignition, no lights were on, it wasn't windy. Temp was maybe 60, a little overcast, and the inside wasn't overly warm. Toward the end of the event, the sound pitch went up just a little, then it stopped. Haven't heard it since.

Anyone ever heard what I'm describing? I'm guessing there's a simple explanation, but it's escaping me at the moment.

Evaporative emissions self-test. Normal.

Help: Motor-type noise when vehicle turned off????

Thanks for the info and the link (plus the subsequent link to the motor.com article). That's interesting. I figured it was a normal noise, but it's the first vehicle I've owned that did anything on its own after being off so many hours.