You need to check each wire . Individually.
Unplug 60 pin and unplug the cam and crank sensors. Then put the black lead of DVOM on ground at engine and probe each wire to the sensors, voltage , return and signal leads, to be sure one of them isnt shorted. They should all read infinite.
9 volts isnt a problem, at least I dont think so. Each component has a tolerance factor or an acceptable amount of deviation from spec. Between that and test equiptment tolerance value, it could read 9 volts.
You can check it against another meter to be sure yours is accurate, or if not, at least how far off it is.
If the wiring checks out, I would have to lean back on a defective PCM from the get go.The coil circuit and its operational conditions you described are not right, and the function originates at the PCM.
Be sure you do not just have a bum coil. Try one off of a running truck, or bolt the one in question on a running truck.
Fact is stranger than Fiction