02 Bugeye WRX alarm siren
 

Hi,

My UK spec 52 plate WRX has an issue where the alarm (siren) keeps kicking off without any understandable cause. The car battery itself doesn’t seem to be a problem as it starts fine and I’ve charged it up to make sure. The siren goes off sometimes while I’m driving along (very embarrassing) or when it’s sat at home on the drive. The key fob works to lock and unlock the car but doesn’t turn the siren off, and it isn’t triggering the immobiliser which makes me think that it’s a siren specific issue. I’ve checked the door/latch buttons too.

it’s part of the standard Sigma m30 alarm system, does anyone know if disconnecting the siren will trigger the immobiliser or other unwanted effects?

I’ve accessed the siren next to the wiper motor, with the aim of disconnecting it and seeing if that helps but it is a sealed unit so I’m having trouble levering it open, any tips would be really helpful.

Had this issue on my sons bug,water gets in the siren.
you can disconnect it at the sigma unit above the steering column or unscrew the siren casing and unplug the circuit board.
Alarm will still work but obviously won't make any sound.

“The siren goes off sometimes when I’m driving along”

🤣🤣🤦‍♂️🤦‍♂️🤦‍♂️

that’s hilarious 😂

Thanks, I hadn't even spotted the screws in the slots down the side. It's now open and I've disconnected the battery, do you know if this is all it needs or if I need to go whole hog and pull it off the circuit board? Currently it can still make a noise as I've tested opening the boot when it's locked, but it's a beeping rather than the full siren. If the battery doesn't stop that, I'm not really sure what it powers?

https://cimg5.ibsrv.net/gimg/www.sco...bade87b82c.jpg

The battery is the battery back up so the alarm will still sound if someone disconnects the main car battery.
Disconnect the circuit board then it will never go off but the alarm/ immobiliser will still work.

You know that's been tampered with inside?
is this why it's going off?

That's how they are , Cable ties and all:thumb:

This has worked for stopping it going off, which is a massive relief! Thanks for your help. For anyone looking for a solution for this in the future;

You'll need a cross head screwdriver and a socket set with a couple of different sizes.
​​​Before starting, disconnect battery from car.
​​​​​​1. Remove windscreen wipers and pop out the plastic cover over the windscreen wiper motor.
2. Unscrew the siren unit from the bracket in the center of that compartment-this is fiddly!
3. Open siren unit using screws set into the grooves at each side of the unit.
4. Remove the connection to the 9v battery and pull out the siren from the circuit board.
Some pictures attached to help.
https://cimg7.ibsrv.net/gimg/www.sco...fa960c2623.jpg
Siren located in the center of the compartment under the wipers
https://cimg8.ibsrv.net/gimg/www.sco...97bd9e350a.jpg
The bracket holding the siren in is a pain to get off, a flexible socket tool might be needed.
https://cimg6.ibsrv.net/gimg/www.sco...2f5f9cb338.jpg
Screws dug into grooves to open the unit
https://cimg0.ibsrv.net/gimg/www.sco...7af6f0b0c7.jpg
Siren and battery disconnected


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This may solve my problem on 03 wrx. Alarm randomnly going off in middle of night with battery on good charge. Also had the alarm go off whilst driving on motorway. At least the 9v must be dead as disconnecting battery stopped it. I just want it all to end!:wall:

So, just to clarify, when I get to the box, can I just cut off the siren and remove the battery and maintain car locking etc or do I disconnect circuit board and leave siren connected? Ta!