2000 challenger mpem

[NitroHunter]

I have a 2000 challenger model 5672. For some reason mpem is not turning on or giving response. Checked voltage coming in, attempted to connect candoo pro to see if any reading. Unfortunately no response, buzzer works, checked dess post, all reading comes back as a good dess post. Any other suggest? All fuses are good none of them are burnt. Not sure what to do at this point.