[goonar]

Got in my F30 the other day and the car thought the boot was open. It was not open and I tried opening and shutting it multiple times, but nothing changed. Has anyone else ever had this happen or might know what is causing this? No work has been done on the car in a while and the issue seemingly popped up at random. There is no fault code stored in ISTA pertaining to the boot lock.

[dmaxdmax]

That sounds like it might be an issue with one or another wire going into the trunk lid.

I ran into that many times with my E46's loom. Not sure where ours is hiding, but it'll be on one side of the trunk hinges. The break will probably be where the wire bends, and it'll probably be inside the insulation and not visible...so you need to yank the wires apart hard away from the bend to find the broken or near failing wires.

That said, if you didn't have the warning light when you turned off the car, I wonder if you might just have blown some fuse or have a bad trunk lock mechanism...maybe a loose connection to the mechanism?

Do some more investigating with a good led flashlight...maybe you'll see something 'off'?

Good luck.