R172 SLK alarm keeps going off

[MBNuB]

The alarm on my wife's SLK has gone off unprompted twice in the last couple of days.
Is there anything I should check? Or do we need the dealer to check it out?
We're about to go on holiday and don't want to infuriate the neighbours while we're gone.
No windows/doors left open/ajar. Any ideas?

 

[LostKiwi]

Check for dust in the interior sensors if you have them. Also check the battery - if they get tired they can trip the alarm.
If you're concerned just disconnect the battery.

 

[Blobcat]

A moth or a flying bug is a common cause, you can disable the interior motion sensors (should be a button with a radar type wave symbol on it inlaid in a picture of the car). On a previous car air blowing in through the vents also caused the alarm to activate at the most inopportune times

 

[MBNuB]

Thanks chaps.
I think the battery is OK but I'll stick to on charge to be sure.
I'll have a look at the sensors, if I can find them, and see if I can identify the interior sensor button.
Many thanks for your input.

 

[mioba]

Could also be a sign the siren is failing. It’s located under the front wheel arch. Wheel and liner out job to replace.