Great write-up, Gary! This was just what I was looking for and confirmed my suspicion that the crank position slots are pretty good size compared to the generic picture shown in the manual below.
 Here's a link to my oscilloscope video of the position and reference signals in action. The top signal is the position signal generated by the inner ring of slots, every 60 degrees, and the bottom one is the reference signal generated by the outer ring of slots, every 1 degree. As I rev the engine more signals occur per unit time resulting in the signal squashing down like an accordion. The ECU counts how many squares occur over some amount of time. More squares means the engine is running faster. Why did I go through the rigor of checking the CAS signal with an O-scope? I'm on a witch hunt trying to solve an erratic timing problem which is likely CAS sensor related. In the 1993 FSM page EF & EC-171 indicates the approximate voltages you would read using a regular voltmeter: 1.2-1.4V for the crank position sensor (ECU pin 41 or 51) and 2.5-2.7V for the crank reference sensor (ECU pin 42 or 52). These are erroneous voltage measurements relative to the real fluctuating voltage signal you saw in the video which a voltmeter just isn't able to pick up but is nevertheless a useful way of determining whether your CAS is operating correctly or not. The beauty of this design is that it's very accurate and fast, small changes in rpm are immediately picked up by the finely spaced 360 degree slits, and it's very robust, entire slits or sensors have to be blocked by dirt for the CAS to become inaccurate. In fact the disk can be warped like an old vinyl record, and like an old slightly warped vinyl record it'll likely still work ok. A great big thanks to Agner.S(CT) for letting me borrow his expensive scope to check this out on my car. Thanks for the e-mail and reposting, Gary.
Zarcasm(Hfd, CT)
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