Car wont start, no spark.
 

1996 audi a4 quattro manual 2.8 AFC

I scanned it with vag-com and here's what I have

1 fault found 16721 crankshaft position sensor g28 or g4 signal too low. P0337 92-00 UNKNOWN ERROR ELABORATION

Which one of these sensors control ignition? I understand that g4 is the CPS and G28 is the vehicle speed sensor. I parked the car yesterday after driving it for sometime and now it won't start. No dtc's prior to that, just seized to start one day out of the blue. I'm trying to figure out which one of these sensors I need to replace.

i have had experience with both of these failing. both had same symptoms. i would recommend just picking up a speed sensor at a local junkyard or on a part out here/vortex since it's prolly gonna be easier to replace over crank position sensor.

Fixed it, turns out it was the CKP sensor. Not as difficult as I thought. Speed sensor is actually more difficult to replace. I've noticed that my old sensor has been scored by the crankshaft how can this be? Is it missing a spacer or something?