Will a defective PCM cause a misfire on one cylinder

If PCM is bad it would give a random misfire,check the compression on the cylinder that is not firing,may have bad valve on it.

I have already pulled the new coil and put a new plug in it and grounded it and then started the engine...but no fire to the plug from the coil...could that still mean possablility of a low compression problem? If low compression can cause the coil not to fire, I will run a compression check in the morning if you still think so

No,if you do not have fire at that plug,there is a issue,may be bad spark plug wire,

The PCM uses input signals from the cam and crank sensors in order to activate the spark with correct timing. Depending on the design of the vehicle there and be different types of ignition coil systems and coil packs. Many modern cars use a coil on plug or COP design. With a two pin system or simple coil system the control transistor is located within the pcm and can fail resulting in a no spark on one or more cylinders. With a four pin coil design the transistor is located within the coil pack itself and can be tested at the coil by applying power and ground and then replicating the pcm signal using a test light on the trigger pin.