Hey guys,

So I have a 2003 Durango with the 5.9L and the notorious "no bus" issue. I realize that this is one of those dreaded problems with now easy fix. I have new symptoms.... Well at least I think they are new. I have yet to find anyone having these problems through searching. Yesterday I got in to leave a restaurant that we had been in for maybe an hr. The truck started with no problems, I drove maybe 50 yards and then it died. I had the "no bus" light on which made me check my main connections like grounds. Nothing was loose or heavily corroded. I did some quick searching while sitting in the parking lot and saw that this could possibly be a pcm issue so I took all three connectors off and re-seated them. After sitting for about 20min I tried to restart the truck, which it did, and then drove probably a half a mile and it died again. Tried to do the same things over again and could never get it to start again. I had it towed home and spent all night doing my research. This morning I checked to make sure the the "no bus" message was still showing before I started testing all of the sensors and it was still... even with the truck cool. I used the TSB that was posted but had a weird issue. I pulled the connector from the TPS sensor and had 5V on the reference wire. I did this will all sensors except the governor pressure sensor and I have 5V on all reference wires. I unplugged all of the sensors, except for the trans case connector and still had the "no bus" message with 5V on all reference wires.

Now I am stumped!

Obviously I have no shorts within the sensors so why am I still getting the "no bus" message? I have read tons of posts and have read about guys with rams and dakotas who have found shorts in the column and loose connections in the main fuse box under the hood but had different symptoms than I do. Could the durangos have the same issue? My cluster has all of the lights on but the gauges dont move. I would love to think that its something with the pcm but if that was the case I shouldnt be getting 5V at any of the senors right?

Any other leads would be awesome. Im thinking im at the point of having to order some wiring diagrams from ebay and just running continuity on each wire that is connected between the pcm and cluster.

Thanks in advance guys!!

 

Oh, and im more than certain that im guessing correctly but a dead fuel pump won't cause a "no bus" message would it? Should the "no bus" message come on right away? I have to wait 10 - 15 min before I get the error.

 

If it takes some driving to happen, it sounds like something is getting hot and causing the issue. When my crank sensor went bad this winter it would drive fine for about 15 minutes then start randomly dying. I never had the no-bus message though.

 

you might have to replace the computer this is what i had to do .the voltage regulator is in the computer not on the alternator and when it goes out you get the no bus