Turn ON the ignition, with the engine OFF.
Disconnect the CKP sensor.
Measure the voltage from the CKP sensor 12 volt reference circuit and a good ground.
Compare the measured voltage with the system voltage.
Is the difference more than 0.5V?
If not replace the CKP.
If yes, test for a short to ground in the CKP 12 volt reference circuit or the CMP sensor 12 volt reference circuit.
Test for poor connections at the coils.
If problem isn't solved there has to be a ground issue somewhere or check fuses again.
Check and clear all DTC's and scan again.

I'd start here and rule out the CKP and CMP.