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Hello and welcome to just answer. The reason the 2 junkyard PCM's would not work is because they came from Jeeps that did have security alarm. Those PCM's are looking for the "ok to run" message from the security module which your Jeep does not have. So, if you do not want to buy a remanufactured PCM, then you will need to find a good used one that came from a Jeep without the security system.
I hope this information helps, and let me know if you need more assistance with this,
Well there is no way to tell if a PCM came from another vehicle that had a security system. It works like this: If a pcm is installed into a vehicle that does not have security alarm, then it will never look for a SAM module signal. But once a PCM is installed into a vehicle that does have security, then it will become "married" to the SAM module and will always look for the signal from the SAM module. It can not be changed after it becomes married. So the PCMs that you have are the correct ones, but were installed in vehicles that had SAM modules and need to see that "ok to run" signal from it in order to run. Now your question about installing the SAM module from the donor Jeep may work if the wiring harness and connector is there in your Jeep. It seems to me that you would be better off just getting a "fresh" re manufactured PCM from the auto parts store and be done with this asap.