Alarm woes VW Passat - Riz
Just picked up 51 plate passat td130 se. In my opinion a very nice car apart from the fact that the alarm keeps going off every few hours!

Am I doing something wrong when I lock it? I know it has "ultrasonic" sensors which are meant to detect movements internally, but I'm positive there's hasn't been anything to trigger it.

Is this a fault of the sensors or just the alarm system? Any ideas what I should do to solve this, is there anyway to deactivate the motion sensors if their the culprit. Is this is common problem for this model.

Any help much appreciated, as seeing at the mo I'm leaving the car unlocked!!

Alarm woes VW Passat - Halmer
There is an issue of water ingress via the pollen filter which causes a problem with the electrics and hence the alarm. Are the carpets dry on the passenger side under the dash?
Alarm woes VW Passat - Halmer
When you lock it do the indicators flash once?
Alarm woes VW Passat - adverse camber
Does it have a little button on the bottom of the b pillar ? pressing that should disable the internal motion sensors. check your handbook.

the water leak issue does cause alarm probs. do all the interiour and dash lights, etc work properly - they are also controlled by the same ecu.
Alarm woes VW Passat - mark25
Long shot: There are issues with the door closed/locked switches on those cars. The switches are built into the lock mechanism and the solder joints are prone failure. If one of those is becoming an intermittent connection, that could be what's upsetting your alarm. Probably worth checking any other logical suggestions first though.
Alarm woes VW Passat - Riz
Thanks so much for the suggestions gents.

I've looked under the matts on both passenger and drivers side, the carpets are dry and don't look like they have been wet in the past.

Yes the lights do flash once when you press the lock button on the key fob.

So far all the interior lights and electrical gizmos seem to be working fine.

Ah ha, yep the car does have a button on the B -pillar, I've tried it and so far no false alarms as yet. So it looks like the internal sensors are playing up......or maybe too sensitive? According to the handbook you have to press the button each time you lock the car as otherwise the sensors automatically reactivate, I wonder if you can turn them off/deactivate them permanently?

Alarm woes VW Passat - Stuartli
>>I wonder if you can turn them off/deactivate them permanently?>>

I have a VW Bora which also has the deactivating button on the bottom of the driver's side B pillar; it reactivates ready for use again when the vehicle is unlocked.

The idea is that the vehicle can still be left locked for security purposes without activating the alarm if dogs and/or people remain in the car (the windows need to be left open slightly); obviously don't leave people or animals in such circumstances during hot weather.
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Alarm woes VW Passat - Alec
When the alarm goes off the source of the trigger is logged.
The dealer can read this for you, at £70/hour !!, or if you have access to a VAGCOM you can use that.
If you know the source then it is usually an easy fix.
Alarm woes VW Passat - EddyStone
Similar problem this end.
As someone has pointed out this problem can be caused by water ingress via the pollen filter seal. This is caused by the drainage ducts becoming blocked, the ducts are a bit difficult to get at but follow the instructions at

However in my case ( a 52 plate Passat Sport Estate ). This is not the problem. No water ingress, carpets dry. When I set the alarm the indicators do NOT flash. It has been intermittent, sometimes they would flash, however now they do not flash at all when locking. I have changed the rear boot locking mechanism as this is apparantly a common problem on estates, Caused by trying to use the rear wiper/washer when iced up. The hose pops off the rear washer and the washer fluid finds it's way onto the "lock closed" switch. Changed this but it didn't solve my problem so I am now going to change the bonnet closed sensor as these are also known to fail. Has anyone any other suggestions, or am I on the right track. I need desperately to find a cure as the neighbours are getting a bit fed up with 3am alarm calls!!

Thanks Ed
Alarm woes VW Passat - Stuartli
Re VAG-COM. See:
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What\'s for you won\'t pass you by
Alarm woes VW Passat - Glaikit Wee Scunner {P}
When my module on the passengers side was damaged by water leaking from the pollen filter the carpet was NOT wet to the touch when lifting the rubber mats.
So do not assume the problem lies elsewhere.
I wasna fu but just had plenty.

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