S3 Car Alarm - won't stop going off

Schlaag

Bwah
Joined
Jul 10, 2007
Messages
486
Reaction score
34
Points
28
Location
Kent
Hi All. Happy new year.

A nice new year woe for me!

When locking the car (with remote and key) the door LEDs flash really fast and after 30 seconds the alarm goes off.

The alarm also goes off if I leave the car unlocked

Can anyone help me with possible causes? is it a common thing?

Its a horrendously annoying issue as I have to keep disconnecting the earth terminal on the battery whenever parked up!

Can I switch the dam thing off whilst I attempt a fix?

thanks
Dave :)
 
Have you ever replaced the alarm siren? If not near enough guaranteed it is that as it's the same symptoms I had it is a common fault and an easy enough fix. It's caused by the battery backup inside the siren leaking and corroding the pcb, there is a revised part available from audi roughly £120 from memory. I need to replace mine still but had other issues to tend to!
To stop it going off you need to remove the boot carpet and strip down the left hand side and remove the sub as the siren is buried down there you can then unplug and remove it. Obviously your alarm will no longer sound at all but the LEDs on the doors still flash so it appears to anyone else to work.
Probably about an hour to strip out and get the boot back together and it's all posix rive screws from memory plus a few 10mm nuts.
 
  • Like
Reactions: Schlaag
Last edited:
  • Like
Reactions: Schlaag and Nilz
Thank you guys, great info/help there.

If it isn't the siren battery problem, are their any other ports of call to check? As if I remove the siren and the alarm keeps activating, the hazards are going to drain the battery fairly soonish

cheers
Dave
 
Is the battery on your car ok?

I had the issue on mine, as i believe the alarm senses a drop in voltage, which can cause it to trigger.
 
Hi Nilz, I think the battery is fine. Never had any probs with it. Suppose I could stick a meter on it to check. Going to go check out the boot catch area now.
 
Just read your post on the washer jet thread too, it maybe related to that you know.
 
Dunno if this helps but does your interior light flash at all? I had a problem a while back when sitting in the car i noticed the interior light flashing but the dash didn't say the door was open, then alarm kept going off after 30 secs of being locked, slammed the passenger door a few times the light stopped flashing and i stoppped having the problem.
 
guys which plug on the rear hatch is for the alarm sensor?

just removed the siren and alarm still triggers (flashing the repeaters)
 
Im not too sure...

So now that you have removed the siren and locked the car, the led on the door flashes for a few seconds rapidly, then slowly yea??

What happens then, does the alarm get triggered somehow and the indicators start flashing as if the alarm is going off, but now without the siren??
 
Yes exactly that mate. Rapidly for a bit then a bit slower for 30 secs then once its armed, a slower pulse... then after a bit ... kaboom, flashers going off (alarm triggered) obi no sound due to removed siren.

NOW.... I have unplugged everything I can see in the rear hatch bar the wipers and the numberplate bulb feeds.

I've armed the car and nothing has gone off

Thing is, i'm now too scared to disturb anything! I known, process of elimination and all that now you would think.. playing havoc with my nerves.. re arming the system and waiting for the inevitable flashing!

It HAS to be boot sensor related.

Ok, off I go again! :D
 
Plugged one thing in. Alarm went off

Unplugged it again


Still went off

:banghead:
 
have you tried to switch of the ultrasonics? just in case its them. switch on driverside pillar

mark
 
Hi Mark, yes tried that. Still went off.

If anyone near Maidstone/Paddock wood has VCDS, i will gladly pay some £ for a scan
 
Sounds like something is shorting it somewhere in that case....very unusual!!!

Have a look on the VCDS Users map to see if anyone is nearby to help mate.
 
Guys, is the boot alarm sensor here (black plug with audi rings on top of lock )

unplugging does nothing but perhaps it always needs to be plugged in?

KGrHqZHJBFI8ruUCnBSWDQ3BpHg60 12
 
Recently had the same issue with mine....replace the siren, then door switches (due to codes on vag com) both didnt cure the fault.

Late night ebaying saw me buy a new central locking pump (located in the rear by the siren) replace that and job done!

Again this was just for my car but seemed to of exhausted all other possibilities.
 
Recently had the same issue with mine....replace the siren, then door switches (due to codes on vag com) both didnt cure the fault.

Late night ebaying saw me buy a new central locking pump (located in the rear by the siren) replace that and job done!

Again this was just for my car but seemed to of exhausted all other possibilities.

Hi mate. Aaah the square foam covered box? two air pipes going in to it (blue and yellow) ?

Funny you mention that, as the yellow hose connector on my one comes off very easily.

Something to look at aswell I guess!

why did you choose to replace that? did you have a fault with the central locking or just a random replacement in hope of fixing the alarm fault?
 
Random replacement.....but when i ordered it it all started to make sense.....the central locking pump wont register that all the doors are shut...hence the 30sec wait then the alarm going mental i bought second hand unit from ebay for 40 quid and crossed my fingers when fitting it.

Saying that though.....these symtoms are also similar to a sirens internal battery dieing.

When you lock the car does it chirp from the alarm?

Good luck, i feel your pain!
 
Hmmmm. I might try that then. From memory there are no electrics to this pump.. its just the vacuum hoses?

Ive removed the siren but its never chirped, ever when locking/unlocking the car

I've discounted the siren battery issue as even with is removed, the alarm keeps triggering.

Will check out a local breakers for any A3's! thanks mate
 
Hi Mark, yes tried that. Still went off.

If anyone near Maidstone/Paddock wood has VCDS, i will gladly pay some £ for a scan


Try users A3kent or jaya3 for vcds scan near you. :) x
 
Hmmmm. I might try that then. From memory there are no electrics to this pump.. its just the vacuum hoses?

Ive removed the siren but its never chirped, ever when locking/unlocking the car

I've discounted the siren battery issue as even with is removed, the alarm keeps triggering.

Will check out a local breakers for any A3's! thanks mate

Not gaurenteeing this will cure the fault but it did on mine so worth some further investigating.

Keep us posted :thumbsup:
 

Similar threads

Replies
3
Views
1K
Replies
7
Views
1K
Replies
22
Views
2K
NHN
Replies
7
Views
2K