How do you deactivate the passenger airbag on a 2006 Jetta TDI?

First off, any attempt to disable any airbag (or airbag system device) will turn the airbag light on.

Seatbelts is correct, the passenger airbag automatically disables when no one is in the seat.

One thing he did not mention is the passenger seat is equipped with a P.O.D.S. device. This stands for something like passenger occupant detection system. It is a gel filled mat under the lower seat cover. When someone sits down, it displaces the gel and is measured. This system can tell if a child is in the seat or an adult. It actually has five or six different increments - empty, child, light adult, heavy adult, ect. It will deploy the airbag accordingly.

I'm pretty certain that there's no "button" to turn it off. If someone is not sitting in the passenger seat, it should automatically disable. and the read out on your "Passenger airbag on/off" light should be "off". There is probably a way to disable it by screwing around with your fuses, but I wouldn't advise doing that unless you know what's going on there. I have a 2009 Jetta, and there's no button that I'm aware of.

airbags dont have fuses to mess with. They are too much of a crucial part of crash protection to have something as simple as a fuse to make it not work. I would bet you have a wiring problem somewhere or your crash sensors on the front of the car has a problem. My recommendation is to have a dealership look at it. I know its more expensive than your standard mom and pop operation but you know are getting better work.