On pre 2008 VW TDI engines, there was a camshaft position sensor that monitored a disk with patterns, so that sensor was really an encoder - could tell camphase and engine position.
On the modern common rail TDI I don't know what the story is, does it monitor one splot, four slots where one slot is a different size or a double slot, or a pattern enoder.
So what I am wondering is, for both engines, how do you go about hooking up the scope, is there a varying voltage for different encoder positions or a digital word, or what is the story?
Sample cam traces would be great if anyone has these.