Add motion detector to Passat 5.5 ?

Is it possible to add a motion detector to the existing security system in a 2005 Passat 5.5 Diesel?

I know that a seperate remote could control the other VW remote functions as well, but as the VW remote has the key  built into it, and therefore has to be carried around anyway,  I'm trying to avoid a seperate remote in my pockets for that extra security function.

Here's something you could also do if it does have an exterior zone output wire. Take the exterior zone trigger (negative output) and wire it to a relay and have the relay trigger the factory horn. It would only honk the horn for a short time but it might be something to try. It is more wiring but I would maybe see how long the exterior zone trigger is activated and if it's a short length timed output it might give you another feature on top of the factory alarm.

Jim 

Just thinking, wouldn't the motion sensor trigger with a person sitting in the car with the ignition off?

How well did the shock sensor work?? Any false alarms?

My Passat was broken into (passenger window) and the navigation system was ripped out. The factory alarm never went off. Any other thoughts on preventing this from happening again?

The sensor could trigger if you were siting in the car, used the remote to arm the system and then moved (if a motion sensor was used) or created a shock (when an impact sensor is used) but I doubt you would be doing that. Unless you are going to arm the system and then climb out the window. You would first turn off the ignition and the sensor would then become active and may output to trigger the alarm but the alarms not on as yet. The output from the sensor should only be for a second or so and then disconnect. Once you get out of the car and close the door the sensor will not be activated as it has reset and then with the remote the alarm is turned on and THEN if the sensor is tripped it will activate the alarm. There may also be a delay on the factory system to where if it is armed opening up the hood or trunk right away might not set it off.

I've done a similiar addition of an impact sensor on a factory GM alarm tieing into the door switch and then adding a relay to where when the ignition is on the relay opens up the output from the sensor to the factory door switch and then when the ignition is turned off the sensor can activate the dome light and/or the alarm BUT it gets armed while out of the car and enough time passes and the sensor resets itself.

Most sensors have sensitivity adjustments. Have it too high and you will get the alarm to go of if a bird craps on it. Have it not sensitive enough and a ton of bricks could fall on it and not activate the system. Normally on impact sensors the further away from the sensor you get the less sensitive it is. If a sensor is mounted by the front bumper a cartain amount of force will trip the sensor but using the same force on the rear bumper will not set if off. Motion sensors can also be blocked by objects in front of them and are more a line of sight type of sensor.

Factory alarms normally require and opening to be opened like a door, hood, or trunk. If a theif climbs through an open or broken out window the system will not go off. Even with motion sensors if you move slow enough you can get by them. Layers of protection are the best but it also allows for more things to go wrong. If someone climbed through the window maybe add an impact or motion sensor or even add seat pressure sensors. I doubt if they leaned in and got the radio out. I would think they leaned in and with one hand pressed down on the seat bottom for support. 

Jim 

......Did somebody actually steal your factory nav, or was it an aftermarket system. If it was factory, that is the first time I have heard of that happening. [/QUOTE]

The Passat 5.5 was not available with a factory nav in North America. The unit that was ripped off was a Pioneer Avic D1 which unfortunately doesn't have the security of an OEM unit.

However, I bet at least half of the European factory VW navs that are sold on ebay are stolen goods. It's become a huge problem over there.

That worked perfectly for me. We now have an inside motion detector working with the VW alarm system.

Part 2:

What does it take to have that motion sensor trigger a siren istead of, or in additon to, the car horn?