CTIS transducer or solenoid issue?

My CTIS has been working properly. I was getting 4 flashing light errors when my tires were leaking. Got most of that fixed and it was working fine. Then it starting making a noise in the pneumatic control unit. I could hear a solenoid cycling very fast. Machine gun fast: click click click click click. If I pushed any button on the ECU it stopped and resumed normal operation.

Today I get in and start it up and it exhausts one blast of air at the PCU, then goes immediately to the 5 light flash. Reset it...same thing.

I pulled the PCU and tore it down. I cleaned everything inside and lubed the valves. I used the TM and checked the continuity of the solenoid harness and it checked out fine. Put it back together and tried it again...same thing. I can't find any diagnostic to check the pressure transducer to verify if it's bad.

Could a solenoid still be bad if the continuity in it was OK? I was thinking broken wire or a short would cause the fast clicking. I checked it and messed with the wires, wiggled them around, etc. still shows good.

Parts manual shows the solenoids and plug are one part (599760). I'm not finding any online. I'm also not able to find a transducer (599601 NSN 669501329641.

Anyone else go down this road? Anyone know how to test the transducer? Hate to throw in the towel and do away with the CTIS.

We have a PCU that was doing that to we have checked and all solenoids checked out.
We have not retested unit.
I just got another one off a parts truck and all is fine in the Ctis world.

I'm going to step back a bit and look at it further. I still have one leaking wheel O-Ring. Since it warmed up it hasn't been leaking as bad, so I wasn't too worried about fixing it right away. Checked tire pressures and found that one is about 10 PSI lower than the others. The CTIS was working fine and would air up the leaky tire after a while, giving a steady mode light. I thought that the 4 light flash was for a leaky tire, but reading the CTIS troubleshooting manual close shows that it can also lead to a 5 light error.

So I guess the best course of action is to fix the leaky wheel O-ring, then re-evalute.

It would be sooooooooo awesome to get the correct diagnostic cable and be able to pull the actual error codes.