Dodge Repair Questions? Ask a Mechanic for Answers ASAP
You're obviously do the key dance routine in order to get this meassage.
The "P" "ECU" is telling you there is a fault code stored in the Cummins controller. The Cummins controller however does not display fault codes when you do this routine.
The only way to get the codes from the Cummins controller is to use a shop quality scan tool.