Crankshaft rpm sensor
 

Hi guys, sorry if this has been asked before but I have an S4 B7 tiptronic which when I pulled up at a junction today it cut out and would not restart. After 10 minutes she fired up again and upon checking for error codes it showed 16706 ign/distributor eng. speed imp.circ. No signal - no signal/communication
i'm guessing this is the rpm sensor but my question is where do I find the thing, I've looked all over but can't see it,
help !

Dunc.