a3 alarm

[wilkesneil]

Hi all, I have a 2004 audi a3 and the last few nights the alarm has been going off, even wouldn't turn off with the keys in and engine running.
anyone know what the cause may be.

thanx

neil

[NickPicks]

Try a fault code read to see what's setting it off.

[wilkesneil]

will this show up on the ecu though as it didn't go off last night, and it seems to be intermittent.

[Eshrules]

if there's a fault with the car, the first stop, for me, is always a quick fault read.

Doesn't hurt to eliminate possible factors.

[NickPicks]

It'll show up on the alarm module (I think it's module address 35). It should, say something like "Alarm triggered by internal sensors" or "Alarm triggered by door switch". Then you need to figure out why that sensor is false alarming.

I'm not sure if this will show up on a generic OBD scan. A vcds/ vag-com scan will show it.

[wilkesneil]

Cheers guys, It's been ok for the last 2 nights but if it happens again I'll look at getting it in on a diagnostic.
Someone has said due to the temps being -10 some ice/water could have got on the module (not sure about this, but could believe it due to weather.)

[NickPicks]

I had an aftermarket alarm that kept sounding at between 2 and 3 am. The alarm code said it was due to the internal ultrasonics, and this was traced to a design fault where the ultrasonics were too sensitive to sudden temperature drops (as you get at 2am). They fixed it by installing a different module.

The Audi standard alarm shouldn't be sensitive to temperature drop, but it might be due to this extreme temperature.

[rugby85]

MY A3 did this and it seems it is just the weather - it has happened quite a lot recently with the snow and ice and bad temperatures. It is very annoying.

[NickPicks]

There should be a button on the driver's door frame. Push this as you get out and it disables the internal sensors, which are what usually gets set off by the cold.

[wilkesneil]

cheers all, it seems to be ok now its warmed up to -2 lol.

on saturday i couldn't turn the internal sensors or the tow settings on or off.
wouldn't allow for some reason but its all working again and can switch the partitions on and off as normal now.