Weird alarm

[cal45fan]

I get out the car, I press the arm button, it's armed. When I disarm it by pressing the arrow (disarm), the alrm goes off! What's wrong?

[Qsilver7]

May be signs that your battery is about to go tits up. When the car's battery voltage drops too low...it creates a situation where the alarm thinks that the battery is being disconnected in an attempt to steal the car.

If it's been extremely hot in your area...this puts a lot of stress on a battery...or is your battery old?

[cal45fan]

I thought about the battery going low, but the alarm does not go off by itself while parked.

It only happens when I press the disarm button.

[jamesdc4]

Your alarm horn needs to be replaced.

It's not the hood sensor or interior motion sensor or tilt sensor or battery...
WTF is causing my alarm to go off?
I arm the system and when I disarm/unlock with key fob, the alarm sounds for 30 seconds and then goes off. When the alarm is sounding, I can start the car up with no problem (Gumbs will like that ). That is all.
Anyone have any ideas or come across this kind of problem?
Is it the EWS module?
I'm sick of closing the door, opening the rear door and leaning in to lock the car with the center console lock button.

Update on the alarm issue I was having. I changed out the alarm siren/horn (part #6 below) and the problem is solved. No more falsing.
If you are having alarm symptoms like I describe in the first post in this thread, this is the part you need to replace.

DIY for alarm siren replacement:
Alarm siren replacement


Why does my alarm keep going off for no reason?

[cal45fan]

jamesdc4,

Reading up on other posts about this problem, if I remove this alarm siren and I open it up to replace the rechrageable battery, I should be ok. Please confirm.

Just a recap, the rechargeable batttery inside this unit is the culprit of these false alarms (goes off when being disarmed-able to start ignition with no problem), right?

[jamesdc4]

I believe your problem is directly related to the alarm siren/horn. Also, I don't think the rechargable battery is replacable. You have to replace the entire siren.

[cal45fan]

I replaced the Alarm siren horn. Got it from an indie (with persmission) who has a 2000 528i sitting out in the parking lot of his garage that is totalled. I got the roadrunner beep. I just upgraded the horn without any intention. Cool.

Thanks Jamesdc4.