I've done searches but I haven't found what I'm looking for so...

I've physicaly looked at a X24 reluctor ring on an LS1 crank and there are two sandwitched together. I also know that the reluctor ring has either a 3 or 12 degree pulse every 15 degree increments.. i.e. small and big "teeth" on the ring.

What I want to know is does the Crankshaft Position sensor output 1 rings pulses or is it the combination of both rings?

 

The 24X comes from having 24 teeth on the ring; 360/24 = 15, which of course means a tooth begins every 15 degrees. The beginning of each tooth can be used to determine that the crankshaft has rotated 15 degrees, while the length of the tooth can be used to index the crankshaft.

The camshaft position sensor assists in the indexing as well, because there are two revolutions of the crankshaft for a complete combustion cycle. However, the factory service manuals say that the camshaft position sensor is not critical for indexing the crankshaft and the PCM has a fault recovery strategy if this sensor fails. However, it may result in extended cranking cycles as the PCM may end up firing the wrong cylinder the first time it tries to index the crankshaft during start up.

 

I agree with everything you stated. Let me explain, I've created in CAD a reluctor wheel that will allow an LT1 (or any V8 I can put it on for that matter) opti to send correct information to a GEN 3 ECM.

Having looked at a 24X reluctor (GM Part number 12559353), I physicaly counted 48 teeth. 24 on the front ring, 24 on the back ring.

What I need to know is if the crank posistion sensor pics up both rings (i.e. 48 pulses pur revolution) or just the back or front ring (i.e. 24 pulses pur velolution)