Audi A3 2004 Sport Alarm Problem

[Pwatkins]

I have been having a problem with the alarm system going off at various times. The vehicle was taken in by Audi, tested and because they could not find any fault they reduced the sensitivity from 100% to 50%.
After a couple of days without problem it went off again in the middle of the night.
a couple of questions please 1) When the alarm goes off how long do the lights flash for, as I am worried about a flat battery if I am not around
2) does anyone know where the problem lies as Audi do not appear to.

many thanks

paul

[Flash2]

Hello Paul, welcome to the forum.

The dealer diag tool (or any other decent VAG tool) is able to tell you what has caused the last 4 alarm triggers. I've never came across this fault on an A3 but I've had few MK5 Golfs with the alarm going off (same alarm as the A3, I think), and in each case it's been the alarm siren that has been causing the false alarms. No further issues after replacing the siren.
Your Audi garage seem to think the problem is the interior monitor in your case (since they reduced the sensitivity). Can't you arm the alarm with the interior monitor switched off. If it is the int. monitor that is causing it, it should be OK when it's disabled. It would be worth trying just to confirm that's what's causing your problem. On the Golf there is a switch on the O/S B post trim for switching the int. monitor off.

Regards.

Jim.

[Pwatkins]

Jim, thanks for the reply. The Audi dealer checked the alarm history, caused by the interior monitor, and no faults were stored in the system.
When the interior monitor is switched off from the door post I do not have any problems and had been doing this prior to Audi looking at it.
i am sorry to sound thick but if the interior monitor is turned off would the alarm go off if there was a attempted theft/break in ?
So, in short, if I lock the car by remote the alarm goes off at some stage. If I switch off the interior monitor and lock by key I have no problems.
Help !

Paul

[Flash2]

With the int. monitor disabled your alarm will still detect a break in when a door, tailgate or bonnet is opened. Basically, it's just the glass that isn't protected with the int. monitor off.
I'm not sure how it works off the top of my head, but it might be worth disconnecting the ultrasonic sensors to see if the alarm still goes off. That might give you a clue to whether it's the sensor itself or the wiring between the sensor and the ECU that's causing the problem.

[Pwatkins]

Jim, thanks for all your help. I will rebook it into the Audi garage when I have some spare time. At least I know it is still mostly alarmed when I turn the internal sensor off.

Regards

Paul

[Pwatkins]

Jim, just a further thought. My golf clubs tend to "live" in the car. Because of this there is sometimes a considerable amount of moisture about.
Could this cause an alarm problem ?

Thanks