B7 Avant Alarm going off intermittently

[Mcarthurr]

My Alarm is intermittently going off, normally it happens about 30 secs after I lock it but it does not do it all the time.

Not sure if this makes any difference but I had the rear washer issue and had to remove the passenger wheel arch cover to connect the pipe back together, there didn't appear to be any dampness in the passenger footwell but there's a little condensation inside the windows.

Not showing anything up on the local garage diagnostic tests, they mentioned it might be a boot or door sensor but i ain't sure how test that,

Switching off the interior sensors, motion and tilt makes no difference and if left unattended and locked the battery eventually dies, so the only solution is to leave it unlocked... Which ain't good

Dodge

[ROY]

Noticed my rear washer jets stopped working
What's the crack MacArthur ???
Any tips on how to get at the pipe work or where it runs so I can check it???

Check your courtesy lights are working you may find one of the doors isn't triggering the light - just a thought.

[MikeFish]

Doesn't the red LED flash rate tell you which sensor set the alarm off? Or the umber of indicator lashes when you disarm the alarm following it going off?

[Mcarthurr]

Hey Roy, the rear jet problem was caused by a blocked rear jet which caused a pipe at the front to disconnect itself with the pressure, if you try to run the rear jet and water leaks under the car at the passenger wheel then the fix is...
Remove the wheel at the passenger side
Remove the screws that hold in the wheel arch cover
Look straight up and you will see some pipes, might not be obvious at first but I pulled them around till i found the right one,
There is a small black push fit pipe, plug it back in and get a little cable tie to sort it for good
Put it all back together and job done (also clean out the rear connection with a pin etc or it wll happen again)
Dodge

[Mcarthurr]

Cheers Mike will check that out, there are 8 rapid flashes when I lock the car, but I also noticed it sometimes just goes solid for 30 seconds then flashes on and off

[MikeFish]

I ust unlocked mine then relocated it and it flashed (probably about 8 times, I didn't count) quickly, then flashed slowly.
I'm pretty sure at other times it goes solid for the 30 seconds while it sets. It ight only do this after I've just turned the engine off rather than just unlock and relock.
It's not these flashes I was talking about though. From previous experience, almost ever alarm I've had would flash the indicators differently when you unlock it after it was set off, and or the red light would be flashing differently, so next tie it goes off check the red light, check the indicators as you unlock and then check the red light again.

[ROY]

Hey Roy, the rear jet problem was caused by a blocked rear jet which caused a pipe at the front to disconnect itself with the pressure, if you try to run the rear jet and water leaks under the car at the passenger wheel then the fix is...
Remove the wheel at the passenger side
Remove the screws that hold in the wheel arch cover
Look straight up and you will see some pipes, might not be obvious at first but I pulled them around till i found the right one,
There is a small black push fit pipe, plug it back in and get a little cable tie to sort it for good
Put it all back together and job done (also clean out the rear connection with a pin etc or it wll happen again)
Dodge

Cheese mate
Just been out and checked it so caught it in time - yep blocked rear washer jets
Robbed one of the Mrs needles from the sewing box and job sorted
Cheers

[Mcarthurr]

Glad it helped Roy...

Mike I've checked the diode situation and it seems....
1) if I lock the car and it flashes rapidly, then flashes slowly the alarm will start to sound at some point (it usually waits until I'm in a deep sleep and dreaming about the B8)
2) if I lock the car and the diode goes solid for 30 seconds then flashes slowly it sits happily without the alarm going off

There is a section in the manual which says if number 2 happens then the alarm system is not working properly... Wondering if it recognises this when locking so it doesn't sound the alarm.
What I'd really like to do is disable the alarm (a fuse I can pull?) to let me lock it and not worry about the alarm, until I get it sorted.

[Mcarthurr]

Seems I have the makings of a solution,
I bit the bullet and took it to Audi...they did diagnosis and noticed the elements that run inside the rear quarter light windows and the rear window were uneven/dark orange or broken in certain areas. The most likely cause is a dog in the rear has scratched them off and this is causing the Alarm to think the rear windows have been smashed. Its pretty clear to see in the attached photo.

Pending replacement of all 3 rear windows ...so fingers crossed

[adsgreen]

Seems I have the makings of a solution,
I bit the bullet and took it to Audi...they did diagnosis and noticed the elements that run inside the rear quarter light windows and the rear window were uneven/dark orange or broken in certain areas. The most likely cause is a dog in the rear has scratched them off and this is causing the Alarm to think the rear windows have been smashed. Its pretty clear to see in the attached photo.

Pending replacement of all 3 rear windows ...so fingers crossed

photo.JPG

Err... IIRc aren't they just heating elements for the demister?
I've never know a car to have internal wiring for the alarm to detect a smashed window. Normally this is done by ultrasonic sensors detecting a disturbance.

Just theen the other thread - I would say more likely to be tv aerial than alarm. Unless there's a huge fecking blindspot?

[adsgreen]

My bet is that if you've had water in the boot lid then the alarm switch for the boot may be on the fritz.

[PetrolDave]

Err... IIRc aren't they just heating elements for the demister?

No they are not, they are a combination of glass break detection elements and radio antennas - the only heating element is on the tailgate (which is also used as a radio antenna).

[MB2]

Might the sensors be disabled via VCDS to see if is the correct diagnosis & potentially avoid new windows too if being replaced just for the alarm ?

[StandFreeRS4]

I could be barking completely up the wrong tree but I was using my mate's B5 S4 for a couple of months until my new motor arrived. The alarm went off literally a minute after I turned the engine off and locked the door. It also went off during the night frequently. I didn't want to pay to fix something I was only borrowing but in the end got it checked with Vagcom and it showed up as the bonnet catch. Swapped this out and no problems since. 30 quid part.

Like I said probably not your issue as different platforms and models but thought it was worth posting.

[Mcarthurr]

Thanks yes good shout I checked the bonnet catch but the Vagcom/VCDS that Audi are using advise that a back window has been smashed. Also noticed the rear window takes an age to defrost and the radio signal is not good, so it could all be related. Thanks MB2 I may just do this in the interim.