I have a 2004 accord EX 4-cyl. Last night for no apparent reason the alarm went off twice around 3AM. I checked the car and there was no vandalism and no adverse weather conditions that may have triggered it. After the second time, I removed the 20 amp horn/stop fuse from under the hood so that I (and my neighbors) could get some sleep. Does anyone have any ideas as to what might have caused this?
Thank you,
Sleepless in SC......

 

1. You may want to make sure your car battery is not really weak. Battery checks are free at most auto parts shops.

2. The security alarm system is part of the multiplex integrated control system (MICU). The alarm going off by itself can be to a door switch, etc.; but, the hood switch being the issue is more common. Disconnect the connector for the switch (located in front of the hood latch) and see if the alarm stops going off by itself.

3. When the security system sounds, the B-CAN (Body Controller Area Network) stores the last input (security breach history data) that set off the alarm.

The dealer can use HDS (Honda Diagnostic System) to access the stored history data to help find and fix the problem. To access the last security breach history, they would connect HDS to the OBD-II port and review the history data by accessing the Security Menu.

 

Not sure if it's related but my 1998 was making a muffled beep-beep-beep after I got home from work (car has ben sitting for a day or 2). Unlocked the doors, opened them, and it stopped. Locked the doors with the key again, and after about 3 min, it started again. So I disconnected the negative cable. After I few minutes, I went to reconnect the negative cable again and to my surprise BEEP-BEEP-BEEP! Scared the crap outta me. And I DO believe my battery is week. Just got this car, learning...