My 96 Audi A4 Quattro 2.8 loves wake the whole neighborhood at all hours of the night. I know its a stock alarm, and I narrowed the issue down to the cabin sensor. Lately I have just been over riding the cabin sensor with the factory switch on the driver pillar. But i would like to fix or replace the sensor. I have been told it's a motion sensor or maybe a sonar sensor that detects broken glass. I have also been told that if you leave windows down or cracked or live next to a busy street that it will set it off, but neither of those are a factor. All i know is that the manual says to disarm it when leaving a pet in the car, so then why would it be sonar? Either way, I need to fix it. Where is the sensor located? What kind is it? How do i replace it? All help is appreciated.

 

They are called "Ultra-Sound" sensors and detect glass breaking type noises/frequencies. I'm fairly sure there is a right and left side (G170 and G171) located at the top of each B-pillar trim panel, just above the shoulder belt ring. They are attached to the back of the trim panel. As I said, I'm FAIRLY sure about that, not positive though.

As for disarming it when leaving a pet in the car, I do know certain dogs barks can be close enough to glass breakage sound frequency to set off ultra sonic (or ultra sound) sensors.