Hello once again folks, as I continue to battle the issues that come with buying a used 2nd gen I have found that when I go to check codes using the key cycle method it comes up with a “P PCU”, and then “P doNE” and when I hook up an OBD2 code reader it gives me a link error in any key position, any tips or issues that could cause this? I already had the truck check the gauge cluster and no issues were indicated there. Thanks!

 

Try a different scanner..... Local auto parts store will generally scan for free.

 

Alright i’ll try that, thanks. I’m just using the cen-tech harbor freight code reader and it worked fine on my car so that is just what I was curious about. I appreciate the reply!

 

These trucks can be finicky......

 

The 24 valve Cummins trucks have a Dodge PCM (PCU for lack of an "M" in the display) and a Cummins ECM (ECU) mounted to the engine. You should see codes (if present) followd by P doNE for each. Weird that the cluster seems to communicate with the PCM but your scan tool can't.

 

So essentially it would show the PCU message first before any codes normally? Just wanted to make sure it wasn’t indicating an issue with the PCM itself. Thank you sir!

 

Yes. See here for how it should look like: The blurb under the video mentions 2001 may or may not show ECU codes but I don't know what the story is there.

 

Gotcha. You are the best I appreciate the info!