Year & Model? I find that mine, not factory setup 2020 SEL AWD, comes on when parking lights are on when the doors open or close & stay on for a few seconds after the doors close then go off. That's probably due to the aftermarket trailer wiring kit, Curt, that ties into the the drivers side Taillight with a plug & play harness. I'm not sure about the OEM setup, but I imagine that it's similar.