2010 XC90 possible alarm siren issue

[XCF]

I think my siren battery is going bad. For the last odd few nights I’ve been woken by an alarm. It goes for 10 seconds maybe then stops.
Too short to pinpoint if it’s my car on street.

Tonight it went off for longer so I could look at my car but there are no hazards flashing and it was not possible to be sure the alarm was mine. The Volvo red LED on the dash was blinking faster than normal though.

My car main battery was recently replaced (6mths ago). The alarm siren has never been replaced.
No error about alarm activation or error reported in DIM.

I left the car unlocked but the alarm sounded again once 30 mins later. Car still unlocked.

Can I pull a fuse to remove the siren to save my (and neighbours) sleep?

[Andymharrison]

Hard to say without reading the codes but sounds like the alarm module, mine did similar.

Pull the fuse, you will get a message on the dash each time you start but will let you confirm it is the module.

You can cut the module open and replace the battery but if old one has leaked onto the pcb it may be trashed, lots of threads around on how to do it. 2nd hand are a bit pot luck as all pretty old too.

New are around £200 so I decided to pull the fuse to stop the parasitic drain and live with the warning message, that does have implications for insurance though.

[XCF]

Thanks. I’m thinking it’s actually my neighbours car but hard to get outside when the alarm goes off as siren goes for a few seconds only and at random times.

So knowing I have disabled mine via fuse would help rule it out.

Does anyone know what the fuse number is ?

[Harley Dave]

Park your car a bit further away for a while and see what happens?

Cheers

Dave

[XCF]

I live in a small village. I’m already one of a few owners under suspicion by other houses as the potential culprit so I’d rather not move it to potentially annoy someone else in the village.


Was hoping I could confirm the siren works on genuine alarm before and doesn’t once fuse pulled.
Then if the phantom alarm siren goes off tonight and wakes up the village again at 3:30 I could be confident it’s not my car !

[Harley Dave]

I live in a small village too and I feel your pain.

Have a l look at this
https://www.youtube.com/watch?v=tQsvERuapNs
might be fuse 8 under the steering wheel

See attachment too

PS - Same fuse for 2010 model...

Cheers

Dave

[XCF]

Thank you for the image. It was very helpful and I’ve just removed the fuse and confirmed no siren sounds now when the alarm is triggered.

I will see if there is any disturbance tonight!

[XCF]

The alarm continued to go off last night but thankfully it wasn’t my car and turns out it’s a neighbours house alarm. Now I will go back and re able my car alarm but I might take the opportunity to swap the battery in my siren.

Does anyone know if you can access the siren without removing the wheel arch?

[Harley Dave]

https://www.youtube.com/watch?v=0aTgH4REYRo

Once again, You Tube is your friend but it looks like the wheel arch liner has to come out.

Cheers

Dave