zagit, you probably have a burned out bulb. You need to remove the instrument cluster and replace it. Details and pictures on how to remove the cluster are found here:
http://www.pelicanparts.com/techarticles/box_OBD_Mod/box_obd_mod.htm
This pelican parts page is for another mod, but it will help you get to the point where you can change the bulb in the middle. I've attached a photo of the back of the cluster and the bulb's location.
You will need to get a replacement lamp from your friendly Porsche dealership parts counter. Probably costs around 4 or 5 bucks. I'd take the old one (or the whole cluster for that matter) in to get the new one if you have a second car. This way, you can be sure you are getting the right bulb... the parts guys do their best to know their stuff, but I've found numerous Porsche parts labeled wrong or I'm given the wrong thing accidentally. This will just save you a 2nd trip to the dealership.
PS - I want to be just like Toolpants when I grow up. I'm building my picture library every day!
