If you search, you'll find that there are numerous people mentioning this.
It is a result of the fuse that you connected the lights to and is completely normal as the truck energizes that circuit to run tests at certain intervals.
Does this happen all the time or just when you first start driving after the truck has sat overnight/for a while?
21K on mine that falls under the TSB and I have rough shifts first thing in the morning and the occasional clunk/clank when shifting from D-R or P-R. Seems with these trans that is...
Sounds like these hybrids and the Toyota app have some issues that are draining/killing batteries. And on top of that the dealers don't want to deal with it.
Saw a video on a 4th Gen FB group yesterday of a guy that had a god awful grinding sound when he turned the AC on. Sounded like a broken fan blade just spinning into other blades or something.
Turns out, a mouse had chewed through his cabin air filter and got stuck in the blower motor and died...