Join Date: Feb 2006
Location: Indianapolis, IN
If I'm understanding those pics correctly, and the wide spline lines up with #1 TDC then the wide part wouldn't be over the sensor when any of the four were at TDC.
All of it could be interpreted too. The frequency could be used to calculate a delay and the processor clock in the ECM is doing the work. This starts a new hypothesis. The wide part is not as tall as the other points. This suggests the CKP is a variable proximity switch and brings new meaning to the peak voltage check. That half height could be telling the ECM that it's still getting signal from the sensor, but it's neither a high nor a low. So let's assume a failing sensor is dropping voltage. What would the ECM think is happening? Would it basically be seeing two half height segments? If the first part of the theory is correct, the clock would be resetting and skipping an ignition cycle. The other thread in ECM would see the missed cycle for the pair. But the ECM would still be getting signal from the CKP and not throw a code for it. I just think that would be too erratic to stay consistent on a specific pair.
It's just fun to try and understand what's going on with the logic.