2005 S80 2.5T - Alarm Triggered / Service Required

[gvsu4msu]

Recently I have been getting the "Alarm Triggered Check Car" or the "Alarm System Service Required" message on my 05 S80.

Usually it is after I leave work or in the AM I see the message as it has been sitting in the lot all day. Pretty sure nobody is messing with the car. It has been periodic when I see it. A couple of weeks ago the alarm just starting going off by itself, and the other day it went off 3x by itself, 2 of them being while I was standing next to the car because I just turned the alarm off.

As to not annoy the neighbors, I found the fuse for the siren, and pulled it. Of course now I get the "ASSR" message every time I start the car.

Is the Alarm Module also known as the Siren Module? I have read about it being underneath the front right fender. I have read about the batteries going out on those, and they are "hardwired in" so a simple replacement is not possible. As I am new the Volvo scene, could the failing batteries be my issue?

Also, is there a fuse to "deactivate" the alarm system, and if so, does it affect other electrical functions in the car? The "ASSR" message is already annoying me.

I see Siren Modules new around $200-250 - but not sure if this is my problem. I have seen used modules for less, but is that something I want to trust considering the donor cars can be around 8-16 years old.

Any advice anyone can offer would be appreciated. Trying to avoid any trip to the Volvo dealer in town for anything I can fix myself.

Thanks in advance.

[bugeye]

Sounds like the classic alarm/siren battery failure. Our '04 XC70 siren failed in 2011 at ~ 72000 miles. I have read the dealer can turn off the alarm function which will be less $ than replacement.

[jaumegarriga]

I am having the same exact problem. How did you solve it in the end? Thanks.