I have a 2002 Dodge Durango SLT+, with the 5.9L V8, 4X4. I was getting a No Bus code in my odometer and it would not start. I was told it was the ECM. I ordered a new one and had it programed at the local dodge dealership. Now here is my issue. With the old ECM the truck would start on occasion and would die without warning. All warning lights on the dash would come on and gauges would stop working. With the new ECM, it cranks every time like its brand new and will run all day long. However, all warning lights are on and the No Bus signal is still showing in my odometer, as well as my gauges still don't work. So in short with the old ecm it didnt run and gauges worked until truck died. With new ECM truck runs great but gauges don't work and warning lights are still on. What the heck is wrong with my car. The people at dodge scratched there head for a while charged me over 100 bucks and then said. "I have no idea whats going on with your durango." If you have any idea or what not let me know. I know its not a bad relay because my gauges worked with old ECM. I know its not a sensor. Im stuck.......could it be that one of the chips or motherboard in the ECM went out?

 

Had a similar issue with my 2002 Ram truck.
Do you have wiring for trailer (4 flat plug)? Last summer, my 4 flat some how shorted and caused a no bus code. Took me a while to figure it out. Only found it because on day I kept getting intermittent waring lights in the dash. Turned out it was shorting on and off as the wind blew the plug that was hanging from the back of the truck.
May not be your issue, but worth a look.