Passat - turn the alarm off?

Won't be as simple as that - it'll be water in the comfort module or the connector under the passenger seat.

The random alarm sounding is the first it's about to go pop due to water damage.

I looked at that when I bought it 12 months ago. It's as dry as a bone. it's been serviced twice since and the mechanic is happy that water isn't getting in.

I reckon it has a faulty sensor somewhere.

It happens that R D S formulated :

The bonnet sensor is a favourite cause of alarms being falsely triggered on most cars, due to it being out in the weather and salt. Try bypassing it/linking it out for a few days to see if that resolves it.

I guess it's not as simple as unplugging the alarm horn itself as it was on my old mondeo :)

I thought of that but then it would sit there with the lights flashing. Curently i'm simply leaving it unlocked.

So I read, I have a suspicion there may be an issue with the boot sensor as using the rear wash/wipe seems to exacerbate the problem. Though it could be a coincidence.

Your best bet is to ask on a VAG forum and get soemone with VCDS, and code read it first. This *might* reveal what is triggering the alarm. Few of the handlheld scanners will read all the codes.

You could then get them to code the CCM so that it thinks the alarm isn't there, if you like, but it might whinge about incorrect coding.

Possible, as on the mk4 golf there is a known problem with rear wash pipes leaking which ends up on the boot microswitch (£20 and 15 minutes to change) which can show an open boot warning up on he dash (only sometimes) and the boot light won't work which is another sign.

If you open the boot and remove the trim and have a look whats going on. If this is at fault it can confuse the alarm I think in to possibly thinking its open.

I'm not 100% sure this is the case on the passat but worth a shot and thought it could be helpful to say, considering its worse when you use the rear wash.