Q&A

Not sure about your Audi and where it takes its crank shaft position "feed " from, some cars you can put a fly wheel on wrong and it will trough the signal sent to the computer off. If it is a professional garage and they are stumped they can call a service called Identanfix , http://www.identifix.com/Corp/contact_us.htm brilliant service a bank of specialist technicians that have either seen the problem before or can talk the mechanic through a series of tests to perform. I suspect something just got knock off.

is the starter cranking? do you have spark and/or fuel?