Really frustrated. One night at 3:30 am my car alarm went off by itself. I looked out the window, aimed the clicker and turned it off. A few days later it happened again. I searched on the Accord forum. I replaced weak battery, connected pos and neg cables with jumper cable for an hour, reprogrammed key fobs per forum instructions and everything worked fine again. I was so pleased!

Yesterday, my neighbor who was parked behind my car, pulled out to go somewhere. I think he tapped my car. Anyway, I heard the alarm go off on my car. I went to the window (he was driving off) used the key fob to turn alarm off. Great. A few minutes later alarm went off again. I did same thing. fine. Then when I next drove the car, I went to click lock it and although it locked, the lights didn't flash and no chirp. When problem continued, I drove home, disconnected battery cables, 1/2 hour later connected pos/neg with jumper, left for an hour, reconnected and the problem wasn't fixed. I want to choke my neighbor, but it might not be anything he caused even if he bumped the back of my car.
I'd appreciate HELP!

Update: I redid the steps above this morning and reprogrammed the key fobs. The lock button will still not make lights blink or chirp. I'm wondering how to re-set factory installed alarm system in case this needs done.

 

Security systems are a pain to diagnose. Try to find the owner's manual. If not search the web.

If this was my car, I would probably completely remove the security system.

 

The security alarm system is part of the multiplex integrated control system. The security system is incorporated with the power door locks. When the vehicle is locked with the door key, lock ****, door lock switch, or the remote transmitter, the security system is activated. The system will completely set 15 seconds after the hood, doors, and trunk are closed.

The security system monitors the following signals:

• Battery voltage
• Door lock **** switches (unlock)
• Door switches (any door)
• Ignition key switch (turned to ON)
• Radio security ground
• Security hood switch
• Trunk key cylinder switch (lock/unlock)
• Trunk latch switch

If any of these switches change from their normal position, (open or closed), the security system reports a violation and sounds the alarm.

Since your security system is not arming normally (e.g., chirp or lights blink), it sounds like either a door switch, door lock actuator, hood switch, etc. may be the cause of the issues you've been experiencing.

 

PA vs. Redbull's answers depend whether it is the stock alarm vs. aftermarket alarm system??

 

Thanks for the help. At least I understand the issue, even if I can't fix the problem myself. (It's factory installed alarm system).

 

Just to rule out the security hood switch, there is a gray 2P electrical connector at the hood switch. Disconnect that connector and see if your security system arms normally.

You may have to remove that black plastic cover on top to access the connector.

 

Redbull, I'll try it. Do you know how to access the trunk switch? I've had a box kitty litter in it that slid around as I braked, for several weeks. Never imagined it might knock something electrical out of balance.

 

1. The trunk latch switch is on the trunk lid. If there is a trunk liner on the trunk lid, then clips are detached to remove the liner to access the latch switch. If there is no trunk liner, then it should be readily accessible. -- You can't just disconnect the 3P gray connector and close the trunk lid to test the alarm, as the trunk lid opener solenoid needs power from the 3P connector to operate.

2. The trunk key cylinder switch is on the right side of the trunk lid. It has a 3P blue connector.

 

Thank you for the guidance. I am both, new to this forum and up there in age so please excuse any lapses in decorum.

I have a 2005 Accord. Alarm was working fine but now the key fob locks the doors but no chirp and no alarm. Recently had an issue with passenger side regulator so replaced that. Also had some items in trunk that rolled around when braking. Is there a way to test the different sensors/switches to troubleshoot the culprit?

Thank you all.