[FIXED] Diagnosed a faulty PCM but am not confident

I don't know what els the problem could be, but my mind just keeps racing around about all of the things I might have missed! I am working on a: 2014 RAM 1500 with a 5.7 HEMI.
It had a p0440 and a p0441. General EVAP code, and Purge solenoid performance code. So first thing I did was, check the purge valve. So I cleared the codes, and went into a bi directional mode, and commanded the purge to start duty cycling. I did not audibly hear anything. That seemed like something that would cause a purge performance issue. So I chased it. I back probed the solenoid, and was only getting a few millivolts on both the wires. (I was verifying my BAT connections every step) At first I thought maybe the bi-directional control wasn't working. I unplugged it, and found my answer. I had 6-7 volts on one wire, and 0 on the other. Ok so we have a power side switched solenoid. I did verify this on a wiring diagram. The power is being duty cycled, and 6-7 volts was within MFG spec. Ok great. Plug it in, and poof, switched power goes to 10mV. So I unplug it, 7 volts again. Put a grounded test light up to it, and poof, 10 mV. Is it bias voltage? I command it off while unplugged, it goes from 7 to 0. Turn it on, it goes back to 7. Ok, so at this point, I am not throwing a solenoid in it. So I bypass test the solenoid, and it works. With the motor running, I can feel vacuum and a full seal, when I go on and off. Perfect. I know that this is not a bad solenoid. To the PCM. 7 volts @ the PCM. Plug it in, or connect test light, it drops it to 10mV. I unplug the connector, and send power from the PCM back probe, and power the solenoid. It works. I drag tested with a .5mm probe. Drag tested fine. I even bypass tested the solenoid, front probed at the PCM. This PCM driver will not support any current flow. I called a bad PCM.

So that is my drag story. A few questions come up for me.
Why didn't it throw a P0443 Purge valve circuit code?
Could this somehow be a driver shut down from a FTP reading/ESIM reading?
What if there is a faulty power feed to the PCM that is feeding this driver?
Maybe a bad PCM ground causing this? (It was only the purge solenoid acting up though?)
What am I missing?

Can somebody please just help me sleep at night? I am freaking out. lol. Thanks in advance. I am really looking forward to some feedback from ye old wise ones on this awesome informational website.

P0440 General EVAP System Failure
P0441 EVAP Purge System Performance


The P0440,41, are monitor tests the PCM performs using the Purge Solenoid. The code gets set from ESIM (Evaporative System Integrity Monitor) See attached Diagram.

P0443 is a hard fault for the operation of the purge solenoid. You don't see this code more than likely because the PCM believes it to be operational.

Here is a diagram and some INfo

Might be worth to check before condemning the PCM

Same feelings here! I hate calling computers....makes you worry all day and all night that you missed something. If you have checked and double checked all the powers and grounds to the pcm and found them to be good, I'm not sure what else it could be other than the pcm. If you command the purge valve on and off with a scan tool, other inputs shouldnt matter should they? I feel as though you've made the right call (provided the powers and grounds are good)

Ok guys! Update time.

I still had that nasty feeling and did one more check, before I blew hundreds of dollars. I went into a the "system tests" rather than the "functional tests" on the Snap On modus. And I went to do a purge flow test. And this test required the engine running. And allowed me to activate the purge solenoid while the vehicle was running. And as soon as I did this test, I could audibly hear the solenoid over the motor, I had a pulse width on my scope. And then I could also watch my fuel trims plummet, confirming purge flow! So I returned the unopened computer box, and moved on to go find the real issue with these purge flow codes. But a lesson to be learned! You can't lean on your bi-directional controls.

Any way....I still had to find the problem. So now that I knew the purge valve was working, there was something els causing this purge flow code. So I lifted the vehicle, and found that the tank had been out already for one reason or another, and when reassembled, the vent hose was completely pinched off between the frame and the tank. So that was a pretty obvious problem. I fixed that and cleared the codes. I cannot confirm the fix just as of yet. The only thing I wasn't confident about, was the the ESIM and it function. The one thing that bugged me, was the fact that I could not get that thing to switch states with the ESIM forced monitor test. So the ESIM switch might not be functioning, but frankly I can't get any consistent solid information on it to prove anything conclusive with this system. And considering it takes weeks for the time logs to add up in the PCM, I just sent it, and said, "I fixed a confirmed problem. Only time can tell us if another EVAP code will arise." And I left it at that.