If your VW won't star or randomly cuts out when you are driving, it could be the engine speed sensor ( sometimes called the crankshaft position sensor ). If the ECU doesn't get a signal from this sensor it will cut out the ignition. The engine code for this failure is P0322: Ign/Dist. Sped Inp Circ No Signal.
It's not a hard fix, but unfortunately this thing is tuck behind the oil filter and not so easy to get at. There is just one bolt ( 5 mm i think? ) holding it in. Some folks say you don't need to remove the oil filter to get at it, I was not able to do it that and wasted about 45 minutes trying to loosen it up. The part itself should cost between $80 and $100 dollars. You can save yourself about 200 bucks doing this one yourself.
Good Luck.
