Audi A4 1.9 tdi avant intermittant alarm

**barneylad** · 26-02-2008,09:31 PM

Its just driving me nutz! my alarm seems want to go off at all sorts of times of day and night for no apparent reason! rapid indicator flashing and wailing i open the car which shuts it up and then lock again and it goes again i repeat the above and then nothing for hours and even days, i called rac and they cant disable it what could it be? any ideas would be really appreciated or how do i pull the plug on it all together? the car is an x reg 2001

**Ben** · 26-02-2008,11:27 PM

Year of car?

**barneylad** · 26-02-2008,11:29 PM

x plate 2001

**nickynibbles** · 27-02-2008,10:21 AM

Heard of this before, your alarm unit has probably had it, or the back up battery needs changing. The unit is sited behind the side panel in the boot on the passenger side. Check the battery voltage, if its below 12v then try changing this 1st. If still no luck then i'd change the whole alarm unit, about £100 I think but it'll need coding to the car. This should be picked up if the car is scanned for fault codes so try that 1st.

**jonbaker** · 27-02-2008,02:05 PM

Originally Posted by nickynibbles

Heard of this before, your alarm unit has probably had it, or the back up battery needs changing. The unit is sited behind the side panel in the boot on the passenger side. Check the battery voltage, if its below 12v then try changing this 1st. If still no luck then i'd change the whole alarm unit, about £100 I think but it'll need coding to the car. This should be picked up if the car is scanned for fault codes so try that 1st.

Nicky, i have no problem with my alarm going off but i do know the horn isn't sounding when activated. Could changing this battery you talk of cure this? if so, how easy is it to get to the battery, how much roughly and where can me and barneylad purchase it?! cheers in advance

**nickynibbles** · 28-02-2008,10:25 AM

Originally Posted by jonbaker

Nicky, i have no problem with my alarm going off but i do know the horn isn't sounding when activated. Could changing this battery you talk of cure this? if so, how easy is it to get to the battery, how much roughly and where can me and barneylad purchase it?! cheers in advance

Do you mean the horn dosent sound when the alarm is going off or just when you lock the car & switch on the alarm? If you mean it dosent sound when the alarm goes off this could just be a connection issue. If you mean it dosent sound when the alarm is switched on this is a feature you have to activate via vagcom.

The backup battery is purely there to sound the alarm should some thieving scumbag try to be clever and disconnect the battery thinking the alarm wont go off.

**jonbaker** · 28-02-2008,02:47 PM

Originally Posted by nickynibbles

Do you mean the horn dosent sound when the alarm is going off or just when you lock the car & switch on the alarm? If you mean it dosent sound when the alarm goes off this could just be a connection issue. If you mean it dosent sound when the alarm is switched on this is a feature you have to activate via vagcom.

The backup battery is purely there to sound the alarm should some thieving scumbag try to be clever and disconnect the battery thinking the alarm wont go off.

The horn doesn't sound when it is actually going off. Hazards go off but no sound. Are you saying that even if the back up battery is cream crackered, as long as the main batt is still connected it should still work? Where EXACTLY is it situated?

I've hijacked this thread slightly, apologies for my rudeness!

**Mitch22** · 28-02-2008,05:47 PM

Had intermittant alarm sounding after thinking my car was amphibious. Tried to go through a road that I was told was flooded about 8-10 inches. Turned out to be about 2 Feet!!!! For next few days alarm kept going off then it obviously dried out and alarm was normal. Don't know if your problem could be similar...i.e. damp problem....just a thought! Hope u get it sorted.

While we're on the subject my alarm has never been very loud. Should the horn also sound when the alarm activates? Any info greatly appreciated. Mitch

**nickynibbles** · 29-02-2008,10:58 AM

Originally Posted by jonbaker

The horn doesn't sound when it is actually going off. Hazards go off but no sound. Are you saying that even if the back up battery is cream crackered, as long as the main batt is still connected it should still work? Where EXACTLY is it situated?

I've hijacked this thread slightly, apologies for my rudeness!

My understanding is the main battery would be used to power the system during normal operation, the back up is there should the battery be disconnected. If your getting no sound when the alarm sounds i'd say the alarm unit is shot. Not having heard the Audi alarm im assuming it like others i've had before where the horn & siren sound together. If your getting nothing then no signal is coming out from the alarm unit at all. change it!!

**jonbaker** · 29-02-2008,02:10 PM

Originally Posted by nickynibbles

My understanding is the main battery would be used to power the system during normal operation, the back up is there should the battery be disconnected. If your getting no sound when the alarm sounds i'd say the alarm unit is shot. Not having heard the Audi alarm im assuming it like others i've had before where the horn & siren sound together. If your getting nothing then no signal is coming out from the alarm unit at all. change it!!

Thanks, is it easy to change myself?