2000 Dodge Neon Did I kill the PCM

I’m having a really bad day and I’m not sure why. Maybe someone with better knowledge then me can help. I have two 2000 Neons. 1 is an ES with all the toys and the other is a bare bones SE. Both have automatic. I took the ES to the dealer to reprogram the keyless entry fob I bought. They did the job OK but the car died a half mile from the dealership. I had it towed home and I’ve been troubleshooting it for two days. It cranks fine. The timing belt seems to be OK because the valves move when it cranks. It has gas. I checked the pressure and it’s OK. I checked the ignition module and it’s OK. So I thought maybe the PCM was bad and that’s where I screwed up. I took the PCM out of the other Neon and tried it in the ES. Nothing. But when I put it back into the original car the engine would start but it would die almost immediately. I fiddled around with it starting and stalling and then suddenly it wouldn’t crank at all. The battery was OK because the lights were bright but when I turn the key the headlights don’t dim and I hear nothing. So I got the bright idea of putting the PCM from the ES into the other car. It did exactly the same thing. It cranked fine and started but died immediately. It did this seven or eight times and then it refused to crank just like the other one.
I know now you have to match up the PCMs or have them programmed with the serial number but can you kill one if you don’t? I hate to think I’ve killed 2 of the darn things through my own stupidity. Thus the cause of my really bad day. The only codes I’m getting are 1684 and once I got a 1193. Please, I’m tearing my hair and contemplating buying any other car besides a Neon.