Hi, I noticed (after my partner's GLE got broken into) that the alarm on my 218 doesn't arm. I have checked with the dealer that it does indeed come with one, and they said it does. (They are totally unhelpful beyond this.)

However, I see no flashing light in the console to indicate that the alarm is arming, when I lock it. And it doesn't go off when I lock and then open it from inside, or even if I unlock it with the 'emergency key element' (with Keyless-GO deactivated). I'd like some help diagnosing this. Where do I start?

Install trunk monkey.

Or, have the dealer tell you what codes they saw, if any. I suspect if it's supposed to work and it doesn't some module, somewhere left a code. Any phone app related settings? Do t use the app myself, so wouldn't know.

The alarm horns generally have a battery (replaceable through soldering) in them, but you really need to get a proper scan to know what the deal is.

Thanks for the responses, guys.

Ill add though that the price of a scan if you dont have xentry, is more than the cost of the new alarm siren.