My horn randomly goes off. I live in an apartment complex snd have had some notes on my car. When I hear it I click the unlock button on my key fob. I disconnected the hood and truck latch as I saw this could help. I took the car to Honda and they did a diagnostic test and said it was the hood latch. I wanted to hold off spending $800 so I've kept the sensors disconnected and the horn still randomly goes off. Had the battery checked and that is fine. Any other suggestions? Don't see how it's the hood latch sensor if I have it disconnected. I took out the horn fuse but then I got the "check charging system" message so put that back in. Thank you!!

 

For the 2012 Civic , if it is due to the hood switch, just disconnecting the switch won't stop it.

Normally, on the 2012 Civic, when the hood it closed, it sends a negative (ground) signal through the hood switch to the multiplex system. If the hood switch is open or faulty, no ground signal is sent; so the multiplex/security system thinks the hood is opened.

Get a piece of wire or small paper clip and jump (i.e., insert one end in each terminal) the 2P black connector that would normally plug into the hood switch. This will send a ground signal and simulate that the hood is closed.