Alarm woes

[NeilF]

My Disco2's alarm seems to be having an identity crisis. Shortly after locking the car with the key fob, 3 or 4 mins, the alarm will suddenly go off without any intervention. It takes repeated presses of the key fob to turn it off. Thereafter, the dashboard LED lights with a continuous rapid flash until I turn on the ignition. My immediate thought was that the key fob battery was on its way out, so I replaced that, but to no avail. Any ideas?

[bear]

Hi Neil,

Try locking it with the key and see if it still goes off. This will rule out the volumetric sensor/s that detect movement inside the vehicle. I've read guys having problems with moths causing this. The LED is flashing to notify you the alarms be activated.

Regards,

Griff

Edited September 22, 2018 by bear

[NeilF]

OK, I'll try that, though the problem is very intermittent - I hate intermittent problems! 

[teabag]

The rapid flashing of the LED will notify you that alarm is inactive. The ultrasonic sensor can go over sensitive if faulty, locking will isolate that item.

I assume that the central locking is fully functional so no issues there.

Edited September 22, 2018 by teabag

[BogMonster]

On some vehicles, and I forget which ones, there was a problem at one point with the interior sensor getting damp inside and causing random alarms. You can tell what the previous alarm triggers were caused by with a diagnostic, which is the best way. But locking with the key will isolate that sensor as a test, as stated above.