2006 mazda 6 2.3 crank no start. No DTC's

Im working on a 2006 mazda 6 with a 2.3 for a crank no start. There are no DTC's customer has replaced cam and crank sensors. There is no spark at all 4 coils. Has an RPM signal. All 3 wire coils have good ground and 12v power supply. The vehicle has good injector pulse and fuel pressure. No security light.  When checking correlation to a known good capture, timing appears good. When checking turn on signal to each coil i noticed that all 4 coils have a command at the same time but roughly only 4 volts. When unplugging coils, voltage slowly goes up but never reaches 12 volts. I havnt found clear information about coil control but can only assume its a 12volt signal control. Is this a default strategy by the pcm for another issue or am i looking at a pcm failure? Pcm.has good powers and grounds. I did notice that when unplugging all 4 coil that my control wires have 200k ohms of continuity. When unplugging the pcm it shows OL. My pictures show known good correlation on top part of first image and vehicle in questions cam/crank correlation on bottom part of image. Second image is of relative compression and ignition coil control 4 for cylinders 1,2 and 3. I feel like im ready to call a PCM but also feel that im overlooking something. 

Hey CPayton! Thanks for the scope captures.

Seeing all the coils firing at the same time is definitely a red flag. There's no reason I can think of that the PCM would do that during normal operation. I think you're looking at (at least) part of the problem.

Typically, three-wire coils like this don't use 12V signals. Normally they're 5V or less. 4V sounds entirely normal, IMO. Since you already have a scope, you could use a current probe on the ignition coil power feed(s) to confirm primary circuit operation. If you're seeing 7-10A of primary current flow with your existing signal voltage, you know that a lack of amplitude is not the problem.

If you're seeing less than 7-10A of coil current, I'd suggest rechecking the coil powers and grounds during a starting attempt. Add a ground if you're in doubt. If the engine now starts, you know you're on the right path.
 

After an engine swap on the same car (2006 Mazda 6i) I had the same symptoms. crank, no start ,no codes.

The plugs weren't firing.

Traced it back to a tiny ground wire which connects to a bracket near the drivers side head.
Locate the thermostat housing and look for metal brackets that hold the hoses etc to the lower right of the thermostat housing.

Good luck