I have killed a few ecm due to bad grounds. I quit buying the mopar ecm boxes and use hei modules. The last few mopar ones I’ve had seem crappy, the hei works better and uses the same four wires as the mopar box. Lots of info on how to do it on this site. Good grounds very important, I run a jumper wire from the ecm mounting bolt to known good ground no matter what box i use now.