Help please - Audi A3 2.0 TDi - alarm problem!

[hotfuss73]

Hi - I hope you can help! I have a 4.5yr old Audi A3 2.0 TDi and 2 days ago the alarm started sounding for no apparent reason outside my house. I unlocked and then locked the doors, and it worked for a short while, then the alarm sounded again so I repeated the unlocking etc. 36 hours later I was driving to work today and the boot open sign appeared on my dash. When I got to work, I opened and closed the boot, then locked the car (therefore setting the alarm.) Since then, the alarm has been going off all morning, and even when I disable the alarm (by pressing the button inside my car door), it still makes the alarm sound. I've had to leave the car unlocked, which isn't ideal. Called Audi who tell me (without seeing it and charging me an initial £60), that I need a new 'siren' which is going to cost upwards from £300 including labour!! I have a feeling that this may not be the problem - can anyone please help?! Thanks, Ali.

Optional Information:
Year: 2004
Make: Audi
Make (other): A3
Model: TDi
Engine: 2.0

 

[FactionOne]

First of all, welcome to ASN.

Secondly - As per your PM I guess you've got to grips with posting (it's a shame it looks like a copy & paste from somewhere else though ) - I'll move this to the A3 8P section where you're likely to get more responses...

Thirdly - I'd be inclined to say it's absolutely nothing to do with the siren - and more likely related to the boot lock (I seem to remember this has been a bit of an issue with both 8L and 8P A3s to some degree). I guess if you have the car scanned for diagnostic trouble codes using VCDS (VAG-COM) or similar, you'd get a better handle on the issue - it should show exactly how the alarm has been triggered, and I'd guess it'll state the boot switch...

It's probably worth a search on the forum, or there may even be something in a Frequently Asked Questions post...

Regards,

Rob.

 

[robos rado]

Hi,

Ive got exactly the same issue on mine, the boot open sign keeps comming up intermitently when driving and then the alarm goes off when its parked up!

I took out fuse 35 (i think) to disable the alarm (no siren) so i can at least lock it but the hazzards do sometimes still go. Ive also found that if i slam it hard it doesnt happen as much !

Anyone any ideas what it could be?

and yes im also new to this forum but im a regular on Club GTI and MK1 owners club, my other car is a MK1 GTI currently in the process of a 16v transplant !

Ste

 

[robos rado]

Think ive fixed mine, took the back trim panel off, made sure all the connectors round the lock and on the boot lid were in properly (loads of them), then covered everything in loads of WD40. Ive put the fuse back in and it all seems fine, no warning light when im driving and no alarm going off..... yet :icon_thumright:

 

[wesley]

It will without a shadow of a doubt be the microswitch on the boot lock, take off the plastic trim that covers the inside of the boot lid and you will see the lock with a wire attatched to it, thats the microswitch which tells the car the boots shut, either its faulty or may be wet as i have found on the Gf's in the past. Remove the wire and check all is dry, squirt of WD40 and put everything back together and you should be fine.

 

[Ashishin]

Wesley, I owe you a beer! Thank you.
Just had this same problem start tonight. Boot warning comming on while driving. Then I got home, locked up and went inside. Then the alarm started beeping. No matter what i tried it started again about 2-3 minutes after locking and activating the alarm. Scratched my head...lots! then read your post.
Popped the boot and removed the trim. Found the wire and the connector was corroded to hell. Cleaned it up and wd40'd it.
put back together and hey presto!! Fixed!!
Also found that my wiper pump was leaking which caused it.
So thanks again

 

[mike foster]

Wesley, I owe you a beer! Thank you.
Just had this same problem start tonight. Boot warning comming on while driving. Then I got home, locked up and went inside. Then the alarm started beeping. No matter what i tried it started again about 2-3 minutes after locking and activating the alarm. Scratched my head...lots! then read your post.
Popped the boot and removed the trim. Found the wire and the connector was corroded to hell. Cleaned it up and wd40'd it.
put back together and hey presto!! Fixed!!
Also found that my wiper pump was leaking which caused it.
So thanks again

You will need to replace the wiper motor or the whole problem will start again. Very common problem on A3's bet it's about 2005 - 2007 model year !

Also make sure the pipe joints are ok because that can cause the same problem.

Or you could just de-wiper and disconnect the power to the rear washer pump !!!

 

[Anton787]

Afternoon all, followed this post with interest as had the same fault tracked down to a faulty washer motor, now disconnected. Unfortunately before replacing I was called away with work. On my return attempted to start the car no joy no attempt to fire up and plenty of warning lights.
breakdown company have been out and said the ecu is not talking to the engine.
Open to suggestions or just to confront my fears that it needs a complete rewire and replacement ecu which audi currently recommend.

 

[_a3sport]

Afternoon all, followed this post with interest as had the same fault tracked down to a faulty washer motor, now disconnected. Unfortunately before replacing I was called away with work. On my return attempted to start the car no joy no attempt to fire up and plenty of warning lights.
breakdown company have been out and said the ecu is not talking to the engine.
Open to suggestions or just to confront my fears that it needs a complete rewire and replacement ecu which audi currently recommend.

Mine done something similar when the boot lock sensor first went. Wouldn't start then sometimes it would with no lights on dash or no lights on centre console and plenty of warning lights on speedo when it did work. Left it an hour or two and it started fine. I think the alarm drains the battery and that gets the ECU(s) into a confused state. Once you get it running take it a long drive and get the battery charged up. If your sensor is shot you'll need to disconnect the battery to stop the alarm going off. You could remove alarm fuse, I am not sure if lights will flash or not (and drain battery).

 

[Anton787]

Cheers for the response can't even get the engine to start, neither could the breakdown guys any tips?

 

[_a3sport]

Reset the ECU? I do not know the "official" procedure but I suggest you disconnect the battery for half an hour reconnect and try again. Did the breakdown guy who diagnosed an ECU problem not think of this!?

 

[Radford212]

This happened to mine, I disconnected to boot switch (stopped the alarm going off, only downside was I couldn't open the boot ) until I was able to take it to the garage, luckily this should be covered in my warranty. When I removed the plastic boot cover to inspect the problem it was soaking wet inside and the wiper motor was leaking for fun :/

 

[Anton787]

Thanks the water pump was definately the cause, now replaced but the ecu is no longer communicating with the engine according to the diagnostic. Unfortunately as its an 07 plate I'm out of warranty.

 

[hotfuss73]

Sorry guys, I was off line for ages having started this thread yonks ago!! In case anyone is still having issues, the problem with my alarm was solved by looking at the boot lock. There was a tiny piece of plastic dislodged and once I cut that off the alarm was absolutely perfect.

Interesting that Audi Watford wanted to charge me upwards of £300 without even giving that a thought!

Thanks all

 

[dancupra225]

Alarm question mine when I shut the door it goes off beep beep beep then open door press the two buttons on side then shut again works no alarm, what fuse is the alarm in the engine bay or inside please Fed up with it