[2JPW]

I have an undervoltage on the alarm siren.
Does anyone know where it is located?
I thought NSR wheel arch, but I found out today that it isn't there!
Is it the other side or am I just looking in the wrong place altogether?

[F32_Sierra]

it's behind the front bumper. Bottom right side, under headlight when looking at it with the hood up

[Pentland]

https://www.realoem.com/bmw/enUS/sho...diagId=65_2303

According to realOEM it’s higher up than you are looking.

[2JPW]

Thanks. Found out this morning it's not in the front RHS!

[t5pilot]

I believe it's rear offside. That's certainly where the audible arm/disarm beeps come from.

[2JPW]

Well it was in the osr wheel arch and tucked away towards the rear of the car.
Bl00dy typical though as the batteries cannot be replaced on this particular model.

Thankfully BMW have come back today and told me they will cover under my extended warranty 👍

[PG325]

How did you know the battery was failing?

I recall on my old Astra, when that battery was giving up, it emitted a beep every so often.

More worryingly, my car is a 2013, and yours appears newer, I wonder how long they're supposed to last?

[2JPW]

Low voltage detected when running a scan via OBDII. BMW have agreed to cover on my extended warranty.

I also replaced the main battery in the car and kept checking. It was discharging more than I would expect and apparently when the batteries go in the alarm it can draw current from the main battery.

[ripvan]

What was the trick to removing the siren bracket?
It appears there are 2 clips on the top outside edges, but is there another clip or catch somewhere on the bracket?
In my case (2016 328i) the siren is tucked up high in the left rear wheel well.