does anyone know whygm went with two crank sensors on the northstar v8?

 

Dual crank sensors originally came on 3800 buick engine but there was just 1 part with 2 sensors built in to it. They did it for "Quick start" The idea was with 2 sensors monitoring different things car would start faster. The 2 sensors read the same interuptor on crankshaft just at different angles for the "Quick start" feature. Quick start - the idea engine could turn half as many turns and start. The benafit is car may still start with just one.