I have the original PCM and the BCM is the same one that’* been in there. The new PCM was programmed to my vin number and I’ve put the original back in before with the same results.

so they are in there? Then you should have to do the immobilizer re-learn but after that it should "should" be back to normal conditions

Would you mind explaining the immobilizer relearn? Is that similar the the anti theft relearn?

I dont have the same service data pulled up, but if its either passkey 3 And not passkey 3+ OR if they never changed the procedure, here:

scratch that. your PCM is the heavy hitter in this year and not the RCLDR or whatever(The keyless entry thingy) like when passkey 3 was new. so if you have a HP tuners,
But

without getting into the service data, google has this which seems to be close at least to what it was in the old days, just a Message on screen instead of a Telltale Security Relearn

1. With a master PASS-Key III key, turn ON the ignition, with the engine OFF.
2. Observe the STARTING DISABLED DUE TO THEFT message on the driver information center (DIC), after approximately 10 minutes the STARTING DISABLED DUE TO THEFT message on the DIC will turn off.
3. Turn OFF the ignition, and wait 5 seconds .
4. Repeat steps 1-3 two more times for a total of 3 cycles or 30 minutes .
5. With a master PASS-Key III key, start the vehicle. The vehicle has now learned the key transponder information and the PCM has now learned the fuel continue password. IMPORTANT: The vehicle learns the key transponder information and/or passwords on the ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

My car has the PASS Key 3 and I don’t have any HP Tuners unfortunately.
So that is exactly the same as the anti theft relearn procedure I’ve already attempted. The thing is that I never get that message (starting disabled) unless I switch out the BCM for a different one or if I have a door key in the ignition. And when ever that message does come up the car won’t even crank over.
I think I’m having an internal issue inside the BCM.
I really appreciate you taking the time to look all that up though.

door key? The car has 1 key and possibly a valet key if you have content theft deterrent

also this is interesting then. You’re now dealing with a much easier to swalllow problem. At this moment in time, what would happen if you removed battery for 10 min then hooked it up and tried to start ? What codes? Any fuel pump sound? Spark?

For this car the ignition key works for both the door and the ignition lock cylinder so I copied the key for an extra ’door key’
Everything remains the same when I unhook the battery. I still have to use a toggle switch for the fuel pump relay to start the car but it starts and runs. Some slight stutter due to the fuel pump I think. No codes show up
One thing I noticed is that I can barely hear the fuel pump now but it still puts out 60 psi. Before I could really hear it. It might be time for a new one but I wanted to solve the current problem before that.

Why are you using a toggle on the relay? What did you do to the wiring to do this? Can you show pics? Ive asked for you to show pics a few times now..
but also, whats your VIN? I can look and see if there are any BCM or PCM updates needed

The PCM isn’t sending power to the fuel pump relay so I’m using a toggle switch that is inserted into pins 30 and 87 to give power straight the the fuel pump. Sorry I haven’t shown pictures, I’ll do that when I’m around the car again. VIN 2G4WC582471146769

Just a quick thing, did you replace balancer or put the OE back on? if you did that, did you disturb the reluctor ring on the outside edge by chance