haven't really looked in the door jam, but if there is a plunger take it out and and touch the wires together and see if that fixes your problem. If not put it back and try the next door... and so on. Might be a bad switch. Other than that I like the disconnect the battery idea as it could be a confused computer.

 

this piece. give a good tug and see if there's any play in any of them.

 

So I played with all of those and pushed the door-closed button/switches to no effect. HOWEVER, when I mess with the one for the hatch it sometimes makes the hatch do the unlocking thing. I can jiggle it and let go and it will make the i locking sound like 3 times. Ugggghhhh... I wonder if something's messed up with the wiring and it thinks the hatch is perpetually open even though it's obviously closed.

A guy said the dealership will give me a loaner car if I drop mine off for service, so I'm just gonna do that.

 

This is unrelated to your issue, but I'm just curious as to why you keep your spare key fob in the glove box? What would happen if you lost or misplaced your original fob?

 

You're right I should leave it in my house or something. Thanks for pointing that out.

Anyway the "door open" light persisted through to this morning, even through my lunch break. However, the light was no longer present at the end of work today and so I excitedly tried to lock my doors with the key......it worked!

But I'm sure the problem isn't solved. I'm guessing it has something to do with the hatch wire problem I mentioned. Hopefully if this sort of problem persists then it will do something the technicians can easily fix while it's still under warranty.

 

Congrats, you have successfully fried your on board computer.

 

The same thing recently happened on my wife's 2018 Fit. We took it into the dealer yesterday thinking, "whatever it is, at least it is under warranty!". The service department called back about 5 hours later and said the driver's door sensor had been damaged by the seat belt buckle when "someone" had closed the door without the seat belt fully retracted (so seat belt wedged in door busted the sensor). As it was an operator error, not a manufacturer error, we had to pay $164 and wait three days before the parts came in. A cautionary tale with the moral being - always check where your seat belt is before you close you car door.

 

A mine started doing that latest put some of those felt pads to stick to the undersides of wooden chairs in the area where the plunger is to make up for the gap