My Fit had a malfunction which caused my car to think that the rear hatch was open even though it was closed. To figure out where the problem is, I opened up to check the rear hatch lock. There are 2 wire clips going into the lock. When the smaller of the 2 is disconnected, the problem goes away. The "door open" warning light goes off, the remote locking works and the trunk light goes off.

Im trying to figure out exactly what the problem is. Does this sound like the lock assembly need to be replaced?

 

If the. car is still under warranty, you should take it in and have it looked at.

 

It is the switch. The default position is the two wires are in contact, not unlike the dryer door switch. When you close the hatch, it opens the contacts. In your situation, the switch did not open the contacts when the hatch is shut.

 

Wasserball is right. I had a Toyota hatchback with a mechanism like that. There was a small rubber bumper which would separate the switch contacts when the hatch was closed except it would wear out or break or come loose or whatever. I got tired of replacing it every few years so I just pulled one of the wires off it's connector, wrapped it in black electrical tape and stuffed it back. Now it'll never make contact with anything and the light will never come on. Of course if the hatch wasn't closed properly I'd never know but I could live with that. And I did for many years thereafter.

If you play around with the latch mechanism you should be able to see where the electrical contacts are which make and break contact and the means by which that is accomplished when the hatch presses down on it and eventually you'll figure out where the problem is.