I'm fairly new to this forum and am looking for help. I bought my 2005 Cummins 2500 new years ago and after 10+ years and 285,000 trouble free miles it's finally given me a headache. I started it the other day and it freaked out, threw all sorts of codes and won't run well or at all. Fuel rail high voltage code, cam sensor, crank sensor, map sensor, battery temp sensor, throttle low voltage, sometimes 7 codes, sometimes 9. It'll sometimes start and idle, but you can tell it's not happy about anything. It'll die then i can restart it and idle it again. The throttle pedal is unresponsive unless you hold it to the floor for a second then the motor will rev up a lil bit. First I thought maybe the fuel pump was getting weak so I replaced it, the new pump flows equal to the original pump. I replaced the accelerator pedal hoping I had a "dead pedal" that didn't help. Still throws codes and won't run well. Dies instantly if you put it to gear. I cleaned the battery terminals and the engine ground. I pulled the wiring harness above the injectors and it appeared like new. I'm of the opinion now that my computer is fried. I had a TST Power Max on it since new, I removed it and the situation is unchanged. Ideas????

 

first write all the codes down..then erase the codes then start the truck and see what codes come back...i would also check all the wires coming from the fuse block see if any got chewed up by any rodents ...if the wires are fine then start testing the sensors if they all test good then i would suspect the ecm.....scott

 

I have tried to clear the codes but they won't clear. I've tried multiple times to clear them and they won't. The fuel rail, map, throttle, and a couple others won't clear. I have looked for chewed up wires and haven't found any yet. all the connections appear like new. The grounds were also like new.New problem from last night is the check gauges light comes on and the ammeter doesn't work when I get it started and it will idle (unhappily) for a moment. The water in fuel light comes on once in a while as well since this started but with me draining the filter multiple times it's most likely malfunctioning as well.
I'm hoping to get a hold of TST before to long, they must be closed for Thanksgiving week, their tech line won't answer. Anyone have any suggestions on other folks who know the electronics on these things?

 

I know that the battery condition could be the cause. Have you checked your batteries for dead cells. It sounds like the Ecm is freaking out maybe a low voltage issue. It would be worthwhile to put a meter on the batteries with them isolated and see if they are above 12.5 volts.

 

The batteries are new but worth a check. Tomorrow i'm going to run wiring tests from the steering column forward looking for a bad connection en route to the computer.

 

Here are some schematics to help you out. Pay particular attention to the PCM and where it gets it power and ground.

2005 Dodge engine 1.pdf

2005 Dodge engine 2.pdf

2005 Dodge engine 3.pdf

2005 dodge engine 4.pdf

 

Those diagrams are much simpler than the ones in my factory manuals, the ones in my manuals are completely overcomplicated. Thank you very much for taking the time to post these! These are keepers. I'll report back what I come up with

 

I am happy to help there are some other diagrams for the diagnostic data bus. But I would start as simple as I could first. I will be out of touch for a day or so traveling back state side. Hope you get it fixed.