Alarm sounding randomly

[whitegoosedown]

Hello all

My alarm keeps going off randomly. Last night the neighbours complained and I don't blame them.

Problem seems to be getting gradually worse over last few weeks. Everything works ok e.g. indicators flash when alarm set (and when sounding), dashboard immobilser light flashes normally.

Any suggestions on how I can futher diagnose the problem before taking it to garage? Does this sound like a sensitivity issue? (it could be the cat)

Any help greatly appreciated

J

[Simon Audi]

Try turning off the interior sensors and shock / jacking sensors one at a time when you lock the car via the isolator switch to see whats causing the issue.

The switch should be on the door inside edge.

Ciao

Simon

[kenney]

Hi You need to have a fault code read,and in measured value blocks will indicate what is activating the alarm.

[probertm]

Dunno if this helps but i had a similar problem!

http://www.vwaudiforum.co.uk/forum/s...000#post300000 (http://www.vwaudiforum.co.uk/forum/showthread.php?p=300000#post300000)

[towcestervag]

diag test car but two things usually cause this
1) rear washer leak into boot and water running down into boot catch micro switch
2) alarm siren itself

[whitegoosedown]

Thanks for all your advice guys. Trouble is I can't watch the car all the time so trying to establish if it is the internal sensors by switching them on in turn is difficult. I'm taking it for a diagnostic check tomorrow so see if that comes up with anything. I'll let you know!

[VtecJunkie]

diag test car but two things usually cause this
1) rear washer leak into boot and water running down into boot catch micro switch


That is exactly what has recently happened to my mums A3! Rear washer jet hose became disconnected and was setting off alarm.

[whitegoosedown]

Took the car into an auto electrical garage. He plugged in his diagnostic machine and it returned non-specific siren fault. The mechanic noticed there was condensation on the circuitry so he dried it out and put it back together.

The problem stopped for 2 weeks but then started again. I imagine it's when it gets cold (or dark). I am going to take it back to the garage and get the siren battery changed and have the siren unit properly sealed and use some silica gel to help absorb any moisture.

If anyone has any ideas in the mean time please let me know!

[whitegoosedown]

Diagnostic check revealed it to be the alarm siren at fault. How can I fix this?

[whitegoosedown]

I took it to another garage and he replaced the boot catch. He found corrosion in the original one so hopefully this is the problem.

[kite]

Diagnostic check revealed it to be the alarm siren at fault. How can I fix this?
You can buy a new one for around £80 from the dealer
Read this thread on how to fix the leaking batts inside the siren.

http://www.tt-forum.co.uk/forum/viewtopic.php?p=792942#792942