Here is a way to check hall effect sensors(cam/crank). You will need a T pin to probe the connector.

 

I know this is a crazy old thread but it's the closest to the exact problem I'm having and I can't figure it out I'm at buying a new PCM stage. I've tested cam and crank sensors changed them both two or three times. New I AC valve new fuel pump. New battery new rotor and cap. New ignition coil. I have the power to the coil but no spark out and I also am at the noid light testing stage. The tests seem to leave unsureity without a scope but I see a new PCM didn't fix the issue. This truck simply didn't start at the gas pump and I can not get it running. After all of the reading on this Im pretty sure the sensors are working because the PCM is sending signal or reference. Also it protected itself during testing where it shut the 5 v reference off until I turned the key off and on. I am completely stumped and out of ideas other than trying a new PCM and if that doesn't work, well that's messed up. And the fix isn't in this thread. Please help me.

 

Five volt reference should always be there. ASD powers the coil, and injectors. PCM will trigger asd for about 3 seconds at initial key on, after that, only if it sees the engine turning.

Need to see what is missing when it won't start. Fuel, or spark. (or both....)